text:
Gengetopt is a tool to write command line option parsing code for C programs.
This is Edition 2.22.6 of the Gengetopt manual.
This file documents GNU Gengetopt version 2.22.6.
This manual is for GNU Gengetopt (version 2.22.6, 2 November 2012), a tool to write command line option parsers for C programs.
Copyright © 2001 - 2011 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, with the Front-Cover Texts being "A GNU Manual," and with the Back-Cover Texts as in (a) below. A copy of the license is included in the section entitled "GNU Free Documentation License."
(a) The FSF's Back-Cover Text is: "You have freedom to copy and modify this GNU Manual, like GNU software. Copies published by the Free Software Foundation raise funds for GNU development."
Gengetopt is a tool to generate C code to parse the command line
argc and
argv that are part of every C or C++
program. The generated code uses the C library function
getopt_long to perform the actual command line parsing.
This manual is written for C and C++ programmers, specifically the lazy ones. If you've written any non-trivial C program, you've had to deal with argument parsing. It isn't particularly difficult, nor is it particularly exciting. It is one of the classic programming nuisances, which is why most books on programming leave it as an exercise for the reader. Gengetopt can save you from this work, leaving you free to focus on the interesting parts of your program.
Thus your program will be able to handle command line options such as:
myprog --input foo.c -o foo.o --no-tabs -i 100 *.class
And both long options (those that start with
--) and short
options (start with
- and consist of only one character) can be
handled (see Terminology for further details). For standards about
short and long options you may want to take a look at the GNU Coding
Standards (http://www.gnu.org/prep/standards_toc.html).
Gengetopt can also generate a function to save the command line options into a file (see Basic Usage), and a function to read the command line options from a file (see Configuration files). Of course, these two kinds of files are compliant.
Generated code works also if you use GNU Autoconf and GNU Automake and
it is documented with Doxygen comments. In particular,
PACKAGE_NAME and
VERSION are used in the generated code
to print information.
Gengetopt is free software; you are free to use, share and modify it under the terms of the GNU General Public License that accompanies this manual.
The code that Gengetopt generates is also free software; however it is licensed with a simple all-permissive license instead of the GPL or LGPL. You are free to do anything you like with the generated code, including incorporating it into or linking it with proprietary software.
Gengetopt was originally written by Roberto Arturo Tena Sanchez. It is currently maintained by Lorenzo Bettini http://www.lorenzobettini.it.
A primordial version of Terminology was written by Adam Greenblatt.
See the file INSTALL for detailed building and installation instructions; anyway if you're used to compiling Linux software that comes with sources you may simply follow the usual procedure, i.e. untar the file you downloaded in a directory and then:
cd <source code main directory> ./configure make make install
Note: unless you specify a different install directory by
--prefix option of
configure (e.g.
./configure --prefix=<your home>),
you must be root to run
make install.
Files will be installed in the following directories:
additional files
Default value for prefix is
but you may change it with
option to configure.
You can download it from GNU's ftp site: ftp://ftp.gnu.org/gnu/gengetopt or from one of its mirrors (see http://www.gnu.org/prep/ftp.html).
I do not distribute Windows binaries anymore; since, they can be easily built by using Cygnus C/C++ compiler, available at http://www.cygwin.com. However, if you don't feel like downloading such compiler, you can request such binaries directly to me, by e-mail (find my e-mail at my home page) and I can send them to you.
Archives are digitally signed by me (Lorenzo Bettini) with GNU gpg (http://www.gnupg.org). My GPG public key can be found at my home page (http://www.lorenzobettini.it).
You can also get the patches, if they are available for a particular release (see below for patching from a previous version).
This project's git repository can be checked out through the following clone instruction1:
git clone git://git.savannah.gnu.org/gengetopt.git
Further instructions can be found at the address:
And the git repository can also browsed on-line at
Please note that this way you will get the latest development sources of Gengetopt, which may also be unstable. This solution is the best if you intend to correct/extend this program: you should send me patches against the latest git repository sources.
If, on the contrary, you want to get the sources of a given release,
through git, say, e.g., version X.Y.Z, you must specify the tag
When you compile the sources that you get from the git repository,
before running the
configure and
make commands, for the
first time, you must run the command:
autoreconf -i
This will run the autotools commands in the correct order, and also copy
possibly missing files. You should have installed recent versions of
autoconf and
libtool in order for this to
Gengetopt has been developed under GNU/Linux, using gcc (C++), and bison (yacc) and flex (lex), and ported under Win32 with Cygnus C/C++compiler, available at http://www.cygwin.com.
For developing gengetopt, I use the excellent
GNU Autoconf2,
GNU Automake3 and
GNU Libtool4.
Since version 2.19 I also started to use Gnulib - The GNU Portability
Library5, "a central
location for common GNU code, intended to be shared among GNU packages"
(for instance, I rely on Gnulib for checking for the presence and
correctness of
getopt_long function, Use Gnulib).
Moreover GNU Gengen (http://www.gnu.org/software/gengen) is used for automatically generating the code that generates the command line parser.
Actually, you don't need all these tools above to build gengetopt because I provide generated sources, unless you want to develop gengetopt.
The code generated by gengetopt relies on the
function that is usually in the standard C library; however, there may
be some implementations of the C library that don't include it; we refer
to No getopt_long, for instructions on how to check whether
getopt_long is part of the library and how to deal with their lacking
(using autoconf and automake).
If you downloaded a patch, say gengetopt-1.3-1.3.1-patch.gz (i.e., the patch to go from version 1.3 to version 1.3.1), cd to the directory with sources from the previous version (gengetopt-1.3) and type:
gunzip -cd ../gengetopt-1.3-1.3.1.patch.gz | patch -p1
and restart the compilation process (if you had already run configure a simple make should do).
The command line options, which have to be handled by gengetopt
generated function, are specified in a file (typically with .ggo
extension). This file consists of sentences with the formats shown below
(these sentences are allowed to span more than one line). Statements in
{} are optional (the
option sentences need not to be given in
separate lines):
package "<packname>" version "<version>" purpose "<purpose>" usage "<usage>" description "<description>" versiontext "<versiontext>" args "<command line options>" option <long> <short> "<desc>" {details="<detailed description>"} {argtype} {typestr="<type descr>"} {values="<value1>","<value2>",...} {default="<default value>"} {dependon="<other option>"} {required} {argoptional} {multiple} {hidden} option <long> <short> "<desc>" flag <on/off> section "section name" {sectiondesc="optional section description"} text "a textual sentence"
PACKAGE and
PACKAGE_NAME generated by autoconf.
This is required, unless you use autoconf.
package is specified, then it will be used to print the
program name in the output of
--help and
--version, and
also when printing errors (from within the generated parser). If it is
not specified, then
PACKAGE will be used when printing errors,
PACKAGE_NAME in the output of
--help and
--version. Note that if
PACKAGE_NAME is empty, then
PACKAGE will be used also in this case.
VERSION generated by autoconf.
This is required, unless you use autoconf.
--version. This would be used, for
example, to display copyright and licensing information.
args8 you can specify options
that will be added to the command line options of gengetopt itself. For
instance, if you always run gengetopt on your input file with the
--no-handle-error --string-parser -u, you can add these
options in the input file like this:
args "--no-handle-error --string-parser -u"
and remove those recurrent options from the command line.
-) and a dot (
.). No spaces
allowed. The name of the variables generated to store arguments (see
later in this section) are long options converted to be legal C variable
names. This means that
. and
- are both replaced by
- is specified, then no short option is considered for the long
option (thus long options with no associated short options are allowed).
Since version 2.22 you can also specify
? as the short option.
--help. Wrapping will be automatically performed.
--detailed-help9, which will be
automatically generated. Thus, these further details will NOT be
printed with
--help. Wrapping will be automatically performed.
Note that if
--strict-hidden is used, options that are hidden
(See Hidden options.) will not appear in the output of
--detailed-help, even if those options have details.
longdouble or
longlong. If the option is
an enumerated one (see Options with enumerated values) the type
can also be
enum. If no type is specified the option does not
accept an argument.
--help (e.g.,
"filename" instead
of simply
STRING, or
"portnumber" instead of simply
enum. More on this feature
can be found in Options with enumerated values.
multiple flag (Multiple Options) but only by
giving a single default value. It is not possible to specify a list of
default values.
required or
optional. This specifies whether such option
must be given at each program invocation. These keywords were
introduced in release 2.17. Before, you had to use the keywords
yes or
no. You can still use these keywords but their use
is not advised since they are not much explicative.
If not specified, an option is considered mandatory; if you do not want
this behavior, you can require that by default options are considered
optional, by using the command line option
= in case you use a long option, and avoid spaces if
you use short option. For instance, if the option with optional
argument is
-B|--bar, use the following command line syntax:
-B15 or
--bar=15, and NOT the following one
--bar 15.
By using this specification together with
default you can obtain
an option that even if not explicitly specified will have the default
value, and if it is specified without an argument it will have, again,
the default value.
required flag. See Multiple Options.
--help but it can still be specified at command
line12. When hidden options are used, the
command line option
--full-help will also be generated. This
will also print hidden options13. Hidden
options are also displayed in the output of
--detailed-help, if
it is present, along with any details that those options have.
Note that when
--strict-hidden is used, hidden options do not
appear as described above, although they can still be given on the
comand line. That is to say, the
--full-help option is not
generated, and hidden options do not appear in the output of
--detailed-help, even if they have details.
on or
off. This is the state of the flag when the program
starts. If user specifies the option, the flag toggles.
For strings (delimited by
") the following convention is
adopted14: a string
spanning more than one line will be interpreted with the corresponding
line breaks; if the line break is not desired one can use the backslash
\ to break the line without inserting a line break. A line break
in a string can also be inserted with the string
\n. Here are
some examples:
"This string will be interpreted into two lines exactly as it is" "This string is specified with two lines \ but interpreted as specified in only one line \ i.e., without explicit line break" "This string\nwill have a line break"
Moreover, if the character
" must be specified in the string, it
will have to be escaped with the backslash15:
"This string contains \"a quoted string\" inside"
The part that must be provided in the correct order is
option <long> <short> "<desc>"
while the other specifications can be given in any order16. Thus, for instance
option <long> <short> "<desc>" {argtype} {typestr="<type descr>"}
is the same as
option <long> <short> "<desc>" {typestr="<type descr>"} {argtype}
Comments begin with
# in any place (but in strings) of the line
and ends in the end of line.
Notice that the options
-h,--help and
-V,--version are added automatically; however, if you specify an
option yourself that has
h as short form, then only
is added17. The same holds for
In case hidden options are used, See Hidden options, the
command line option
--full-help will also be generated. This
will print also the hidden options18.
Note, though, that when
--strict-hidden is used, this is not
the case and
--full-help is not generated.
If there's at least one option with
details, the command line
--detailed-help will also be generated. This will print
also the details for options and hidden options19 (except when
--strict-hidden is used).
Options can be part of sections, that provide a more meaningful
descriptions of the options. A section can be defined with the
following syntax (the
sectiondesc is optional) and all the options
following a section declaration are considered part of that sections:
section "section name" {sectiondesc="optional section description"}
Notice that the separation in sections is stronger than separation in
groups of mutually exclusive options (see Group options).
Furthermore, sections should not be inserted among group options (but
only externally). A section makes sense only if it is followed by some
options. If you don't specify any option after a section, that section
will not be printed at all. If you need to simply insert some text in
the output of
--help, then you must use
text, explained in
the next paragraph.
You can insert, among options, a textual string that will be printed in
the output of
text "\nA text description with possible line\nbreaks"
Of course, you can use this mechanism even to manually insert blank lines among options with an empty text string:
text ""
You can also specify the list of
values that can be passed to an
option (if the type is not specified, the option has type
string). More on this feature can be found in Options with enumerated values. If a value that is not in the list is passed, an
error is raised. You can think of such options as enumerated
options. It is not necessary to pass the complete value at the command
line option: a non ambiguous prefix will do. For instance, if the
accepted values are
"foo","bar","foobar", then you can pass at
the command line the value
"b" and the value
"bar" will be
selected, or the value
"foob" and the value
"foobar" will
be selected; instead, passing the value
"fo" will raise an
ambiguity error.
Here's an example of such a file (the file is called sample1.ggo)
# Name of your program package "sample1" # don't use package if you're using automake # Version of your program version "2.0" # don't use version if you're using automake # Options option "str-opt" s "A string option, for a filename" string typestr="filename" optional text "\nA brief text description" text " before the other options.\n" option "my-opt" m "Another integer option, \ this time the description of the option should be \"quite\" long to \ require wrapping... possibly more than one wrapping :-) \ especially if I\nrequire a line break" int optional option "int-opt" i "A int option" int yes section "more involved options" sectiondesc="the following options\nare more complex" text "" option "flag-opt" - "A flag option" flag off option "funct-opt" F "A function option" optional details="\nA function option is basically an option with no argument.\ It can be used, e.g., to specify a specific behavior for a program. Well, this further explanation is quite useless, but it's only to \ show an example of an option with details, \ which will be printed only when --detailed-help is given \ at the command line." section "last option section" option "long-opt" - "A long option" long optional option "def-opt" - "A string option with default" string default="Hello" optional option "enum-opt" - "A string option with list of values" values="foo","bar","hello","bye" default="hello" optional option "secret" S "hidden option will not appear in --help" int optional hidden option "dependant" D "option that depends on str-opt" int optional dependon="str-opt" text "\nAn ending text."
The simplest way to use gengetopt is to pass this file as the standard input, i.e.:
gengetopt < sample1.ggo
By default gengetopt generates cmdline.h and cmdline.c. Otherwise we can specify these names with a command line option:
gengetopt < sample1.ggo --file-name=cmdline1 --unamed-opts
The option
--unamed-opts allows the generated command line parser
to accept also names, without an option (for instance you can pass a
file name without an option in front of it, and also use wildcards, such
foo*.? and so on). These are also called
parameters (see Terminology). You can specify an optional
description for these additional names (default is
In cmdline1.h you'll find the generated C struct:
/** @file cmdline1.h * @brief The header file for the command line option parser * generated by GNU Gengetopt version 2.22.6 * http://www.gnu.org/software/gengetopt. * DO NOT modify this file, since it can be overwritten * @author GNU Gengetopt by Lorenzo Bettini */ #ifndef CMDLINE1_H #define CMDLINE1_H /* If we use autoconf. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include <stdio.h> /* for FILE */ #ifdef __cplusplus extern "C" { #endif /* __cplusplus */ #ifndef CMDLINE_PARSER_PACKAGE /** @brief the program name (used for printing errors) */ #define CMDLINE_PARSER_PACKAGE "sample1" #endif #ifndef CMDLINE_PARSER_PACKAGE_NAME /** @brief the complete program name (used for help and version) */ #define CMDLINE_PARSER_PACKAGE_NAME "sample1" #endif #ifndef CMDLINE_PARSER_VERSION /** @brief the program version */ #define CMDLINE_PARSER_VERSION "2.0" #endif /** @brief Where the command line options are stored */ struct gengetopt_args_info { const char *help_help; /**< @brief Print help and exit help description. */ const char *detailed_help_help; /**< @brief Print help, including all details and hidden options, and exit help description. */ const char *full_help_help; /**< @brief Print help, including hidden options, and exit help description. */ const char *version_help; /**< @brief Print version and exit help description. */ char * str_opt_arg; /**< @brief A string option, for a filename. */ char * str_opt_orig; /**< @brief A string option, for a filename original value given at command line. */ const char *str_opt_help; /**< @brief A string option, for a filename help description. */ int my_opt_arg; /**< @brief Another integer option, this time the description of the option should be \"quite\" long to require wrapping... possibly more than one wrapping :-) especially if I require a line break. */ char * my_opt_orig; /**< @brief Another integer option, this time the description of the option should be \"quite\" long to require wrapping... possibly more than one wrapping :-) especially if I require a line break original value given at command line. */ const char *my_opt_help; /**< @brief Another integer option, this time the description of the option should be \"quite\" long to require wrapping... possibly more than one wrapping :-) especially if I require a line break help description. */ int int_opt_arg; /**< @brief A int option. */ char * int_opt_orig; /**< @brief A int option original value given at command line. */ const char *int_opt_help; /**< @brief A int option help description. */ int flag_opt_flag; /**< @brief A flag option (default=off). */ const char *flag_opt_help; /**< @brief A flag option help description. */ const char *funct_opt_help; /**< @brief A function option help description. */ long long_opt_arg; /**< @brief A long option. */ char * long_opt_orig; /**< @brief A long option original value given at command line. */ const char *long_opt_help; /**< @brief A long option help description. */ char * def_opt_arg; /**< @brief A string option with default (default='Hello'). */ char * def_opt_orig; /**< @brief A string option with default original value given at command line. */ const char *def_opt_help; /**< @brief A string option with default help description. */ char * enum_opt_arg; /**< @brief A string option with list of values (default='hello'). */ char * enum_opt_orig; /**< @brief A string option with list of values original value given at command line. */ const char *enum_opt_help; /**< @brief A string option with list of values help description. */ int secret_arg; /**< @brief hidden option will not appear in --help. */ char * secret_orig; /**< @brief hidden option will not appear in --help original value given at command line. */ const char *secret_help; /**< @brief hidden option will not appear in --help help description. */ int dependant_arg; /**< @brief option that depends on str-opt. */ char * dependant_orig; /**< @brief option that depends on str-opt original value given at command line. */ const char *dependant_help; /**< @brief option that depends on str-opt help description. */ unsigned int help_given ; /**< @brief Whether help was given. */ unsigned int detailed_help_given ; /**< @brief Whether detailed-help was given. */ unsigned int full_help_given ; /**< @brief Whether full-help was given. */ unsigned int version_given ; /**< @brief Whether version was given. */ unsigned int str_opt_given ; /**< @brief Whether str-opt was given. */ unsigned int my_opt_given ; /**< @brief Whether my-opt was given. */ unsigned int int_opt_given ; /**< @brief Whether int-opt was given. */ unsigned int flag_opt_given ; /**< @brief Whether flag-opt was given. */ unsigned int funct_opt_given ; /**< @brief Whether funct-opt was given. */ unsigned int long_opt_given ; /**< @brief Whether long-opt was given. */ unsigned int def_opt_given ; /**< @brief Whether def-opt was given. */ unsigned int enum_opt_given ; /**< @brief Whether enum-opt was given. */ unsigned int secret_given ; /**< @brief Whether secret was given. */ unsigned int dependant_given ; /**< @brief Whether dependant was given. */ char **inputs ; /**< @brief unamed options (options without names) */ unsigned inputs_num ; /**< @brief unamed options number */ } ; /** @brief The additional parameters to pass to parser functions */ struct cmdline_parser_params { int override; /**< @brief whether to override possibly already present options (default 0) */ int initialize; /**< @brief whether to initialize the option structure gengetopt_args_info (default 1) */ int check_required; /**< @brief whether to check that all required options were provided (default 1) */ int check_ambiguity; /**< @brief whether to check for options already specified in the option structure gengetopt_args_info (default 0) */ int print_errors; /**< @brief whether getopt_long should print an error message for a bad option (default 1) */ } ; /** @brief the purpose string of the program */ extern const char *gengetopt_args_info_purpose; /** @brief the usage string of the program */ extern const char *gengetopt_args_info_usage; /** @brief the description string of the program */ extern const char *gengetopt_args_info_description; /** @brief all the lines making the help output */ extern const char *gengetopt_args_info_help[]; /** @brief all the lines making the full help output (including hidden options) */ extern const char *gengetopt_args_info_full_help[]; /** @brief all the lines making the detailed help output (including hidden options and details) */ extern const char *gengetopt_args_info_detailed_help[]; /** * The command line parser * @param argc the number of command line options * @param argv the command line options * @param args_info the structure where option information will be stored * @return 0 if everything went fine, NON 0 if an error took place */ int cmdline_parser (int argc, char **argv, struct gengetopt_args_info *args_info); /** * The command line parser (version with additional parameters - deprecated) * @param argc the number of command line options * @param argv the command line options * @param args_info the structure where option information will be stored * @param override whether to override possibly already present options * @param initialize whether to initialize the option structure my_args_info * @param check_required whether to check that all required options were provided * @return 0 if everything went fine, NON 0 if an error took place * @deprecated use cmdline_parser_ext() instead */ int cmdline_parser2 (int argc, char **argv, struct gengetopt_args_info *args_info, int override, int initialize, int check_required); /** * The command line parser (version with additional parameters) * @param argc the number of command line options * @param argv the command line options * @param args_info the structure where option information will be stored * @param params additional parameters for the parser * @return 0 if everything went fine, NON 0 if an error took place */ int cmdline_parser_ext (int argc, char **argv, struct gengetopt_args_info *args_info, struct cmdline_parser_params *params); /** * Save the contents of the option struct into an already open FILE stream. * @param outfile the stream where to dump options * @param args_info the option struct to dump * @return 0 if everything went fine, NON 0 if an error took place */ int cmdline_parser_dump(FILE *outfile, struct gengetopt_args_info *args_info); /** * Save the contents of the option struct into a (text) file. * This file can be read by the config file parser (if generated by gengetopt) * @param filename the file where to save * @param args_info the option struct to save * @return 0 if everything went fine, NON 0 if an error took place */ int cmdline_parser_file_save(const char *filename, struct gengetopt_args_info *args_info); /** * Print the help */ void cmdline_parser_print_help(void); /** * Print the full help (including hidden options) */ void cmdline_parser_print_full_help(void); /** * Print the detailed help (including hidden options and details) */ void cmdline_parser_print_detailed_help(void); /** * Print the version */ void cmdline_parser_print_version(void); /** * Initializes all the fields a cmdline_parser_params structure * to their default values * @param params the structure to initialize */ void cmdline_parser_params_init(struct cmdline_parser_params *params); /** * Allocates dynamically a cmdline_parser_params structure and initializes * all its fields to their default values * @return the created and initialized cmdline_parser_params structure */ struct cmdline_parser_params *cmdline_parser_params_create(void); /** * Initializes the passed gengetopt_args_info structure's fields * (also set default values for options that have a default) * @param args_info the structure to initialize */ void cmdline_parser_init (struct gengetopt_args_info *args_info); /** * Deallocates the string fields of the gengetopt_args_info structure * (but does not deallocate the structure itself) * @param args_info the structure to deallocate */ void cmdline_parser_free (struct gengetopt_args_info *args_info); /** * Checks that all the required options were specified * @param args_info the structure to check * @param prog_name the name of the program that will be used to print * possible errors * @return */ int cmdline_parser_required (struct gengetopt_args_info *args_info, const char *prog_name); extern const char *cmdline_parser_enum_opt_values[]; /**< @brief Possible values for enum-opt. */ #ifdef __cplusplus } #endif /* __cplusplus */ #endif /* CMDLINE1_H */
First of all, notice that the
argv parameter (typically
corresponding to the homonimous argument of your program's
function) is declared as
char ** and not as
char *const
*21. Actually,
the version of
getopt_long in libc uses prototypes with
char *const *argv that are incorrect because getopt_long and
getopt_long_only can permute argv; this is required for backward
compatibility (e.g., for LSB 2.0.1)22. So, it is better to declare
argv as
char ** in the generated parser functions.
<option>_given field is set to 1 when an argument for
<option> has been specified (otherwise it is 0)23. This fields also
counts the times a multiple option is specified (see Multiple Options). If the option accepts an argument and it is not of
flag type The
<option>_arg field is set to the value
passed at the command line. The
<option>_arg field has the
corresponding C type specified in the file passed to gengetopt.
Notice that if an option has a default value, then the corresponding
<option>_arg will be initialized with that value but the
<option>_given will NOT be initialized to 1. Thus,
<option>_given will effectively inform you if the user has
specified that command line option.
The additional field
<option>_orig is always a string containing
the original value passed at the command line. This may be different,
for instance, in case of numerical arguments: gengetopt converts the
passed value (a string) into the corresponding numerical type; due to
conversions, float representations, etc., this may not correspond
exactly to the original value passed at command line. It can also be
different when enumerated options are used (see above): in particular
<option>_arg field will contain a value taken from the
specified list, while
<option>_orig contains the (non-ambiguous)
prefix specified at the command line.
The user can always access this original value by using
<option>_orig instead of
<option>_arg, as he sees
fit24. For instance, gengetopt itself uses the original value when it
saves the command line options into a file (see the
function in the following). However, apart from very specific command
line processing, the user might hardly need the
field, and can be always safely use
<option>_help contains the string (concerning this very
option) that is printed when
--help command line is given.
If it is of
flag type, only the field
is generated.
The strings
cmdline_parser_purpose and
cmdline_parser_usage contain the
purpose as specified in
the input file and the generated "usage" string as printed when
--help command line is given. Finally, the string array
cmdline_parser_help contains the strings (one for each option)
printed when
--help command line is given (this array is
terminated by a null string element). If hidden options are used also
cmdline_parser_full_help array is available (containing also
help strings concerning hidden options). If at least one option has
details, then the
cmdline_parser_detailed_help array is
available (containing also help strings concerning hidden options and
details for options). All these strings can be used by the programmer
to build a customized help output25.
Even if
<option>_given is 0, the corresponding
<option>_arg is set to default value (if one has been specified
<option>). However, in this case, the
is set to
Notice that by default the generated function is called
cmdline_parser (see the command line options below, to override
this name), and it takes the arguments that main receives and a
pointer to such a struct, that it will be filled. Another version,
cmdline_parser2, can be specified more arguments. Since you
typically need this second version only in conjunction with other
"kinds" of parsers such as configuration files and multiple parsers,
you can find more details about it in Configuration files.
IMPORTANT: The array passed to the parser function (that in turn
is passed to
getopt_long is expected to have in the first
element (of index 0) the name of the program that was invoked. This
will be used, for instance, for printing possible errors.
cmdline_parser_free can be called to deallocate memory
allocated by the parser for string and multiple options.
cmdline_parser_init can be called to initialize the struct (it is
not mandatory, since it is done automatically by the command line
cmdline_parser_file_save26 can be used to save the command line options into a
file. The contents of this file are consistent with the configuration
files (Configuration files). Notice that if an option has a
default value, this option will be saved into the file only if it was
passed explicitly at command line (or read from a configuration file),
i.e., default values will not be saved into the file. Alternatively,
you can use
cmdline_parser_dump27 that takes as the first parameter an
already open stream (
FILE *) instead of a file name.
And here's how these functions can be used inside the main program:
/* main1.cc */ /* we try to use gengetopt generated file in a C++ program */ /* we don't use autoconf and automake vars */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include <iostream> #include "stdlib.h" #include "cmdline1.h" using std::cout; using std::endl; int main (int argc, char **argv) { gengetopt_args_info args_info; cout << "This one is from a C++ program" << endl ; cout << "Try to launch me with some options" << endl ; cout << "(type sample1 --help for the complete list)" << endl ; cout << "For example: ./sample1 *.* --funct-opt" << endl ; /* let's call our cmdline parser */ if (cmdline_parser (argc, argv, &args_info) != 0) exit(1) ; cout << "Here are the options you passed..." << endl; for ( unsigned i = 0 ; i < args_info.inputs_num ; ++i ) cout << "file: " << args_info.inputs[i] << endl ; if ( args_info.funct_opt_given ) cout << "You chose --funct-opt or -F." << endl ; if ( args_info.str_opt_given ) cout << "You inserted " << args_info.str_opt_arg << " for " << "--str-opt option." << endl ; if ( args_info.int_opt_given ) cout << "This is the integer you input: " << args_info.int_opt_arg << "." << endl; if (args_info.flag_opt_given) cout << "The flag option was given!" << endl; cout << "The flag is " << ( args_info.flag_opt_flag ? "on" : "off" ) << "." << endl ; if (args_info.enum_opt_given) { cout << "enum-opt value: " << args_info.enum_opt_arg << endl; cout << "enum-opt (original specified) value: " << args_info.enum_opt_orig << endl; } if (args_info.secret_given) cout << "Secret option was specified: " << args_info.secret_arg << endl; cout << args_info.def_opt_arg << "! "; cout << "Have a nice day! :-)" << endl ; cmdline_parser_free (&args_info); /* release allocated memory */ return 0; }
Now you can compile main1.cc and the cmdline1.c generated
by gengetopt and link all together to obtain
sample1 executable:
gcc -c cmdline1.c g++ -c main1.cc g++ -o sample1 cmdline1.o main1.o
(Here we assume that
getopt_long is included in the standard C library;
see Installation and No getopt_long).
Now let's try some tests with this program:
$ ./sample1 -s "hello" --int-opt 1234 This one is from a C++ program Try to launch me with some options (type sample1 --help for the complete list) For example: ./sample1 *.* --funct-opt Here are the options you passed... You inserted hello for --str-opt option. This is the integer you input: 1234. The flag is off. Have a nice day! :-)
You can also pass many file names to the command line (this also shows how flags work):
$ ./sample1 *.h -i -100 -x This one is from a C++ program Try to launch me with some options (type sample1 --help for the complete list) For example: ./sample1 *.* --funct-opt Here are the options you passed... file: cmdline1.h file: cmdline2.h file: cmdline.h file: getopt.h This is the integer you input: -100. The flag is on. Have a nice day! :-)
And if we try to omit the
--int-opt (or
-i), which is
required, we get an error:
$ ./sample1 This one is from a C++ program Try to launch me with some options (type sample1 --help for the complete list) For example: ./sample1 *.* --funct-opt sample1: `--int-opt' (`-i') option required!
Now, let's test the enumerated options, notice the use of a prefix for
specifying an acceptable value, and the difference between the actual
passed value and the one recorded in
$ ./sample1 -i 10 --enum-opt h ... enum-opt value: hello enum-opt (original specified) value: h ...
While the next one raises an ambiguity error (between
$ ./sample1 -i 10 --enum-opt b ... ./sample1: ambiguous argument, "b", for option `--enum-opt'
Here is the output of
--help of the parser generated from
sample1.ggo by specifying the following options to gengetopt:
--long-help -u --show-required (see Invoking gengetopt for
further explanation for these command line options).
This one is from a C++ program Try to launch me with some options (type sample1 --help for the complete list) For example: ./sample1 *.* --funct-opt sample1 2.0 Usage: sample1 -iINT|--int-opt=INT [-h|--help] [--detailed-help] [--full-help] [-V|--version] [-sfilename|--str-opt=filename] [-mINT|--my-opt=INT] [--flag-opt] [-F|--funct-opt] [--long-opt=LONG] [--def-opt=STRING] [--enum-opt=STRING] [-DINT|--dependant=INT] [FILES]... -h, --help Print help and exit --detailed-help Print help, including all details and hidden options, and exit --full-help Print help, including hidden options, and exit -V, --version Print version and exit -s, --str-opt=filename A string option, for a filename A brief text description before the other options. -m, --my-opt=INT Another integer option, this time the description of the option should be "quite" long to require wrapping... possibly more than one wrapping :-) especially if I require a line break -i, --int-opt=INT A int option (mandatory) more involved options: the following options are more complex --flag-opt A flag option (default=off) -F, --funct-opt A function option last option section: --long-opt=LONG A long option --def-opt=STRING A string option with default (default=`Hello') --enum-opt=STRING A string option with list of values (possible values="foo", "bar", "hello", "bye" default=`hello') -D, --dependant=INT option that depends on str-opt An ending text.
Notice how
filename is printed instead of
STRING for the
--str-opt (since
typestr was used in the
sample1.ggo file) and how the description of
--my-opt is
wrapped to 80 columns, and how the
\n is actually interpreted as
a newline request. Also the usage string is wrapped. Moreover, since
-S,--secret is
an hidden option (See Hidden options.) it is not printed;
if you wanted that to be printed, you should use
The option
--func-opt has also the
details, but they are
not printed with
Finally, notice how the
text strings are printed in the help
output (and the empty line after the "more involved options" section
achieved with an empty
text string).
Instead, here is the output of
--detailed-help of the parser
generated from sample1.ggo. You may want to compare this output
with the one produced by
--help (See Output of
--help.); in particular, you may notice that the hidden option
--secret is actually printed and the details of
are printed too:
This one is from a C++ program Try to launch me with some options (type sample1 --help for the complete list) For example: ./sample1 *.* --funct-opt sample1 2.0 Usage: sample1 -iINT|--int-opt=INT [-h|--help] [--detailed-help] [--full-help] [-V|--version] [-sfilename|--str-opt=filename] [-mINT|--my-opt=INT] [--flag-opt] [-F|--funct-opt] [--long-opt=LONG] [--def-opt=STRING] [--enum-opt=STRING] [-DINT|--dependant=INT] [FILES]... -h, --help Print help and exit --detailed-help Print help, including all details and hidden options, and exit --full-help Print help, including hidden options, and exit -V, --version Print version and exit -s, --str-opt=filename A string option, for a filename A brief text description before the other options. -m, --my-opt=INT Another integer option, this time the description of the option should be "quite" long to require wrapping... possibly more than one wrapping :-) especially if I require a line break -i, --int-opt=INT A int option (mandatory) more involved options: the following options are more complex --flag-opt A flag option (default=off) -F, --funct-opt A function option A function option is basically an option with no argument. It can be used, e.g., to specify a specific behavior for a program. Well, this further explanation is quite useless, but it's only to show an example of an option with details, which will be printed only when --detailed-help is given at the command line. last option section: --long-opt=LONG A long option --def-opt=STRING A string option with default (default=`Hello') --enum-opt=STRING A string option with list of values (possible values="foo", "bar", "hello", "bye" default=`hello') -S, --secret=INT hidden option will not appear in --help -D, --dependant=INT option that depends on str-opt An ending text.
If you're curious you may want to take a look at the generated C file cmdline1.c.
You may find other examples in /prefix/share/doc/gengetopt/examples or in the tests of the source tarbal.
This is the output of
gengetopt --help:
gengetopt This program generates a C function that uses getopt_long function to parse the command line options, validate them and fill a struct. Usage: gengetopt [OPTIONS]... -h, --help Print help and exit --detailed-help Print help, including all details and hidden options, and exit -V, --version Print version and exit Main options: -i, --input=filename input file (default std input) -f, --func-name=name name of generated function (default=`cmdline_parser') -a, --arg-struct-name=name name of generated args info struct (default=`gengetopt_args_info') -F, --file-name=name name of generated file (default=`cmdline') --output-dir=path output directory --header-output-dir=path header output directory --src-output-dir=path source output directory -c, --c-extension=ext extension of c file (default=`c') -H, --header-extension=ext extension of header file (default=`h') -l, --long-help long usage line in help --default-optional by default, an option is considered optional if not specified otherwise -u, --unamed-opts[=STRING] accept options without names (e.g., file names) (default=`FILES') The parser generated is thought to be used to parse the command line arguments. However, you can also generate parsers for configuration files, or strings that contain the arguments to parse, by using the following two options. -C, --conf-parser generate a config file parser -S, --string-parser generate a string parser (the string contains the command line) Additional options: -G, --include-getopt adds the code for getopt_long in the generated C file -n, --no-handle-help do not handle --help|-h automatically --no-help do not add --help|-h automatically -N, --no-handle-version do not handle --version|-V automatically --no-version do not add --version|-V automatically -e, --no-handle-error do not exit on errors --show-required[=STRING] in the output of help will specify which options are mandatory, by using the optional passed string (default=`(mandatory)') --strict-hidden completely hide hidden options -g, --gen-version put gengetopt version in the generated file (default=on) --set-package=STRING set the package name (override package defined in the .ggo file) --set-version=STRING set the version number (override version defined in the .ggo file) --show-help show the output of --help instead of generating code --show-full-help show the output of --full-help (i.e., including hidden options) instead of generating code --show-detailed-help show the output of --detailed-help (i.e., including details and hidden options) instead of generating code --show-version show the output of --version instead of generating code Please refer to the info manual for further explanations.
The options should be clear; in particular:
--func-name is given,
cmdline_parser is taken by default;
--output-dir28 is given, the
files are generated in the current directory;
sample1 *.h). You can
specify an optional description for these additional names (default is
--no-handle-help (
--no-handle-version) is given the
command line option
--help|-h (
--version|-V) is not
handled automatically, so the programmer will be able to print some
other information; then the function for printing the standard help
(version) response can be used; this function is called
<parser-name>_print_help (
<parser-name> is the name specified with
or the default,
cmdline_parser. In case hidden options are used,
See Hidden options, also the function
<parser-name>_print_full_help will be generated; if
details are used for at least one option, then also the function
<parser-name>_print_detailed_help will be generated. Notice
that, although the programmer can handle these options manually, the
parser will return after finding one of these options: the other command
line options, if any, will be ignored. In case you want to have full
control on
--version|-V, you should use the
following options:
--help|-h and
respectively. The programmer will then be able to add these options in
the input file and handle them as he sees fit. Notice that
--no-help will also disable the automatic options
--detailed-help and
--full-help. The programmer can still
define options with short character
h and
V as he wants,
but he cannot define options
help and
version, unless he
--no-help and
--no-version, respectively
(otherwise an error will be printed). An example using these options
and manually handles
--help and
--version can be found in
test_manual_help_cmd.ggo and test_manual_help.c in the
examples directory.
--no-handle-error is given, an error in the parsing does not
provoke the exit of the program; instead, since the parser function, in
case of an error, returns a value different 0, the program can print a
help message, as gengetopt itself does in case of an error (try it!).
--show-required is given, possibly with
a string, in the output of
--help will be made explicit
which options are actually required, See Basic Usage.
--full-help option will not be added, and
hidden options will not show-up in the output of
--detailed-help, even if they have details.
See Hidden options.
getopt_long into the generated parser C file.
This will make your generated parser much bigger, but it will be
compiled in any system, even if
getopt_long is not part of the C
library where your program is being compiled. See also No getopt_long.
--full-help and
--version command lines without
generating any code, See Automatically added options.
For instance, I use the
--show-help option to generate a
texinfo file with the output of help (this also shows an example of
use of
--set-package and
../src/gengetopt --show-help -i ../src/cmdline.ggo \ --set-package="gengetopt" \ --set-version="" > help_output.texinfo
You may have already guessed it: gengetopt uses gengetopt itself for
command line options, and its specification file is
in the source directory. In particular the command line for gengetopt
itself is generated with the following command:
gengetopt --input=cmdline.ggo --no-handle-version \ --no-handle-help --no-handle-error
Indeed when
--help|-h is passed on the command line, gengetopt will call
cmdline_parser_print_help() and then the lines for reporting bugs. When
--version|-V is passed, it will call cmdline_parser_print_version() and
then prints a copyright. If an error occurs it prints a message on the
$ ./gengetopt --zzzz ./gengetopt: unrecognized option `--zzzz' Run gengetopt --help to see the list of options.
An argument is an element of the
argv array passed into
your C or C++ program by your operating system.
An option is an argument that begins with -, or --.
A value is an argument, or part of an argument, that is associated with a particular option (an option may also not accept any value). For example, in
> ls --width=80
ls is called with one argument, --width=80,
which is an option that has a value,
80, while in
> ls --width 80
ls is called with two arguments, --width,
which is an option, and
80 which might or might not be a value.
In this case, whether the
80 is treated as a value associated
with the preceding --width option, or as the name of a file to
list depends on how ls parses the --width option.
The order in which options are specified is usually unimportant:
> ls -a -l > ls -l -a
both do exactly the same thing.
An parameter is an argument that is not an option. For example, in
> cp --archive source dest
cp is called with three arguments, the option
--archive, the parameter
source, and the parameter
dest. Unlike options, the order in which parameters are
specified usually is important:
> cp --archive --verbose source dest > cp --verbose --archive source dest > cp --archive source --verbose dest > cp --archive --verbose dest source
The first three cp commands do the same thing, but the fourth one is completely different.
If you're new to Gengetopt, you may wish to skip the rest of this section. It goes into more detail about different sorts of options, and how they are parsed.
Note that some parameters may begin with - or --. Equivalently, not all arguments that begin with - or -- are options. Consider
> ls -- -file > tar -c -f - . > ../foo.tar
The ls command has two arguments; the first
argument, -- is ignored by ls, but causes the
-file argument to be interpreted as a parameter. The tar
command has four arguments. The -c argument tells tar to
create an archive; the -f argument, which takes a value,
-, tells tar that the archive should be written onto the standard
output, and the fourth argument,
., tells tar what directories to
include in the archive. (The remaining two items,
> and
../foo.tar, tell the shell to redirect the tar
command's output to the file ../foo.tar. The tar command
doesn't even see them.)
The GNU convention is that - by itself is always interpreted as a value or parameter, while the first -- by itself is always ignored, but causes all subsequent arguments to be interpreted as parameters. Gengetopt always behaves this way.
A short option is an option that begins with -. Not including the leading dash, short options must be one character long:
> ls -a -l -t --width=80
The -a, -l, and -t options are all short options. Multiple short options may be combined into a single argument:
> ls -alt --width=80
is equivalent to the above example.
A long option is an option that begins with - or --. Ignoring the leading punctuation, long options may be one or more characters long:
> ls --all -fs
The ls command has two arguments; the long option --all, and the pair of short options -fs.
Long options need not have synonymous short options; after all, complex programs like cc have more long options than there are valid short option characters; it wouldn't be possible to assign a short option to each of them. Short options are encouraged, but not required, to have a synonymous long option.
Long options may be abbreviated, as long as the abbreviation is not ambiguous. Gengetopt automatically treats unambiguous abbreviations as synonyms.
Short options may have values just like long options, but if several short options are grouped together into one argument, only the last one may have a value. Values in the same argument as a long option are delimited by an equals sign, values in the same argument as a short option are not:
> ls --width 60 # ok, value is "60" > ls --width=60 # ok, value is "60" > ls -w60 # ok, value is "60" > ls -w 60 # ok, value is "60" > ls -w=60 # unexpected, value is "=60" > ls -T7 -w60 # ok, value for -T is 7, value for -w is 60 > ls -T7w60 # unexpected, value for -T is "7w60", no -w at all
A required option must be present, otherwise an error will be raised.
A multiple option is an option that may appear more than once on the command line. Gengetopt would create a tidy array for multiple options (see Multiple Options, for further details about dealing with multiple options).
You can also specify the list of
values that can be passed to an
option (if the type is not specified, the option has type
string). If a value that is not in the list is passed, an error
is raised. You can think of such options as enumerated options.
It is not necessary to pass the complete value at the command line
option: a non ambiguous prefix will do. For instance, if the accepted
values are
"foo","bar","foobar", then you can pass at the command
line the value
"b" and the value
"bar" will be selected,
or the value
"foob" and the value
"foobar" will be
selected; instead, passing the value
"fo" will raise an ambiguity
Since version 2.22 options with values can be given a specific type (the default is string). If you give a numeric type to such options, gengetopt will check that the enumerated values are actually valid values for that numeric type.
As for other options, the
<option>_arg field will have the
specified type, while the
<option>_orig field will always be a
string (
char *) storing the (non-ambiguous) prefix specified at
the command line.
For such an option, no matter what its type is, an array of strings,
<parser-name>_<option>_values, will be generated that contains
all the strings representing the possible accepted values.
An option with enumerated values can also be given the type
in that case, a C
enum type is also generated with name
enum_<option>; the values of such C enum will be generated
according this pattern:
<option>_arg_<value>, where
is the value specified in the input file, and the starting value is
always 0.
An additional value is generated to represent the null/empty value, with
the pattern
<option>__NULL (note the double underscore) with
integer value -1.
For instance, if we specify in the input file the following
option "myopt" ... ... values="FOO","180","BAR" enum ...
then the following C enum will be generated:
enum enum_myopt { myopt__NULL = -1, myopt_arg_FOO = 0, myopt_arg_180, myopt_arg_BAR };
If you use the symbols
+ and
-, these will be translated
PLUS_ and
MINUS_, respectively, in the the C enum.
Thus, if we specify in the input file the following option
option "myopt" ... ... values="+foo","-all","-foo" enum ...
then the following C enum will be generated:
enum enum_myopt { myopt__NULL = -1, myopt_arg_PLUS_foo = 0, myopt_arg_MINUS_all, myopt_arg_MINUS_foo };
An example using options with values (and enum options) is tests/test_values_cmd.ggo and tests/test_values.c.
It is also possible to group options; options belonging to a group are
considered in mutual exclusion. In order to use this feature, first the
group has to be defined, and then a
groupoption can be defined. A
groupoption has basically the same syntax of a standard option, apart
that the required flag must not be specified (it would not make sense,
since the options of the same group are mutually exclusive) and the group
to which the option belongs has to be specified.
defgroup "<group name>" {groupdesc="<group description>"} {required} groupoption <long> <short> "<desc>" <argtype> group="<group name>" \ {argoptional} {multiple}
If a group is defined as
required, then one (but only one) option
belonging to the group has to be specified.
Here's an example (taken from the test test_group_cmd.ggo):
defgroup "my grp2" defgroup "grp1" groupdesc="an option of this group is required" required groupoption "opta" a "string a" group="grp1" multiple groupoption "optA" A "string A" string group="grp1" argoptional groupoption "optAmul" M "string M" string group="grp1" argoptional multiple groupoption "optb" b "string b" group="grp1" groupoption "optc" - "string c" group="my grp2" groupoption "optd" d "string d" group="my grp2"
The group
grp1 is required, so either
--opta or
--optb has to be specified (but only one of them). Here's the
output of some executions:
$ ./test_groups test_groups: 0 options of group grp1 were given. One is required $ ./test_groups -a OK $ ./test_groups -a -a OK (the same option given twice) $ ./test_groups -a -b test_groups: 2 options of group grp1 were given. One is required $ ./test_groups -a -c OK $ ./test_groups -a --optc -d test_groups: 2 options of group my grp2 were given. At most one is required
It is also possible to specify "mode options"; options belonging to a mode are considered in mutual exclusion with options of a different mode. Thus, you can specify more options belonging to the same mode, but you cannot specify, on the same command line, two options belonging to two different modes (thus, modes are different from groups, Group options).
These sets of options are called modes, since they represent the different modes (modalities), in which a program can be run.
In order to use this feature, first the
mode has to be defined,
and then a
modeoption can be defined. A modeoption has basically
the same syntax of a standard option, and it can be given the required
flag must not be specified (with a slightly different semantics, see
below) and the group to which the option belongs has to be specified.
defmode "<mode name>" {modedesc="<mode description>"} modeoption <long> <short> "<desc>" <argtype> mode="<mode name>" \ {argoptional} {multiple} {required}
If a mode option is specified as
required, then it will be
required only if other options of the same mode are specified; this
makes it possible to specify options of different modes as required.
Options not belonging to any mode are not in conflict with mode options.
For instance, let us consider the file test_modes_cmd.ggo:
package "test_modes" version "1.0" section "some non mode options" option "no-mode" N "a generic option not beloging to any mode" optional option "no-mode2" - "another generic option not beloging to any mode" string optional section "some modes just for testing" defmode "mode 2" defmode "my mode" defmode "mode1" modedesc="any option of this mode is in contrast with any \ option of the other mode\nNotice that this description is quite long so \ it may spawn many lines... \ fortunately gengetopt will wrap it for you :-)" modeoption "opta" a "string a" multiple mode="mode1" optional modeoption "optA" A "string A" string argoptional mode="mode1" required modeoption "optAmul" M "string M" argoptional string mode="mode1" multiple optional modeoption "optb" b "string b" mode="mode1" optional modeoption "optc" - "string c" mode="mode 2" optional modeoption "optd" d "string d" mode="mode 2" required modeoption "mopt" m "option of my mode" int optional mode="my mode" optional
Now, we use the program test_modes (that uses the generated parser for the input file above) to demonstrate how the parser generated by gengetopt perform checks on mode options.
test_modes -N
This execution generates no errors (although there are required options which are not specified, these required options are part of modes and they are required only if that mode is used).
test_modes -a ./test_modes: '--optA' ('-A') option required
Since an option of a mode is specified, then required options of that mode must be provided, but, in this execution, we forgot to specify a required option of the mode that is being used.
test_modes -a -A -N
This execution is correct: we specified two options of the same mode, in particular we also specified the required option of that mode. Notice that we use also an option not belonging to any mode, which does not interfere with mode options.
test_modes -a -A -N --optc test_modes: option --optc conflicts with option --opta test_modes: option --optc conflicts with option --optA test_modes: '--optd' ('-d') option required
Here we see a conflict, (actually two), since the last option we specified belongs to a mode that is different from the one of the first two options.
If you require gengetopt to generate
--full-help.), the usage string will be
generated so that it will show the modes of the program; for instance,
this is the output of
--help of the generated parser for the
input file above:
test_modes 1.0 Usage: test_modes [-h|--help] [-V|--version] [-N|--no-mode] [--no-mode2=STRING] or : test_modes -d|--optd [--optc] or : test_modes -ASTRING|--optA=STRING [-a|--opta] [-MSTRING|--optAmul=STRING] [-b|--optb] or : test_modes [-mINT|--mopt=INT] -h, --help Print help and exit -V, --version Print version and exit some non mode options: -N, --no-mode a generic option not beloging to any mode --no-mode2=STRING another generic option not beloging to any mode some modes just for testing: Mode: mode1 any option of this mode is in contrast with any option of the other mode Notice that this description is quite long so it may spawn many lines... fortunately gengetopt will wrap it for you :-) -a, --opta string a -A, --optA[=STRING] string A -M, --optAmul[=STRING] string M -b, --optb string b Mode: mode 2 --optc string c -d, --optd string d Mode: my mode -m, --mopt=INT option of my mode
Besides the parser functions, in the generated header file, gengetopt
also generates31 an additional structure
<cmd_parser_name>_params that can be used to customize the
invocation of the generated parsers (it is especially useful when using
configuration file parsers, Configuration files, string parsers,
String Parsers and Multiple Parsers, and, in general, multiple
These are the fields of this structure (as usual, boolean options are
represented as
int and they are
true if they are set to
1 and
false if they are set to
int initialize (default = 1)
int override (default = 0)
int check_required (default = 1)
int check_ambiguity (default = 0)
int print_errors (default = 1)
must print error messages to the standard error stream if it encounters
an unknown option character or an option with a missing required
argument. This is the default behavior. If you set this variable to
getopt_long does not print any messages, but the generated
parser will still return with error.
Gengetopt also generates an initialization function for such
structures33, called
which takes as argument a pointer to such structure and initialize all
its fields to their default values; it also generates a function called
<cmd_parser_name>_params_create that returns a dynamically
allocated structure with all fields initialized to their default values.
We strongly advise to use such functions for creating and initializing
such a structure, since this will make your code scalable to future
releases of gengetopt where such structure might contain additional
fields. Otherwise, you might risk to use a structure where some fields
are not initialized, with unpredictable results. Furthermore, since the
<cmd_parser_name>_params_create function returns a pointer to a
dynamically allocated structure (with
malloc), it is up to you to
deallocate that structure when you no longer need it (with
Some examples of usage of this parameters struct are shown in Configuration files.
It is often useful to specify command line options directly in a
configuration file, so that the value of some options are read from this
file if they are not given as command line options. When the command
line option
-C|--conf-parser is given to gengetopt, apart from
the standard command line option parser, also this additional parser is
generated (its name is
int <cmd_parser_name>_config_file(char * const filename, struct gengetopt_args_info *args_info, struct <cmd_parser_name>_params *params);
The parameter structure
<cmd_parser_name>_params is described in
Parser function additional parameters.
For instance,
params->override tells whether the values read in the
configuration file have to override those specified at the command line.
IMPORTANT: you have to explicitly set
params->initialize to 1 if
you call the config file parser before the standard command line option
parser, otherwise unpredictable results may show.
If you call the config file parser before the standard command line
option parser and then you want to call the standard command line parser
you MUST use this second version of the parser function, with
params->initialize set to 0, so that collected values from the
config file are not lost35:
int <cmd_parser_name>_ext (int argc, char **argv, struct gengetopt_args_info *args_info, struct <cmd_parser_name>_params *params);
Notice, that with this version you can also specify whether the options passed at the command line must override the ones read from the config file. Moreover, you have to specify whether the check for missing required options must be performed or not. This concerns also options of a required group (Group options).
If you decide not to request the check for required option, you can test it manually, after the command line parsing returns by using the following generated function:
int <cmd_parser_name>_required (struct gengetopt_args_info *args_info, const char *program_name);
program_name is the name of your executable (usually you
should pass
argv[0] as argument). If the function returns a
value different from 0, then some required options are missing. An
error has already been printed by this function. This concerns also
options of a required group (Group options).
The config file has the following simple syntax: lines starting with
# are considered comments and:
<option_name> = {<option_val>}
or simply (if the option does not take an argument):
which means that
option_name is given, and if it accepts an argument,
then its value is
option_val. The
= is not mandatory.
Since version 2.19, it is possible to include other files (i.e., other
configuration files) in a configuration file, by using the
include syntax:
include "filename"
For instance here's a program that uses this feature (this is the test test_conf_parser):
/* test_conf_parser.c test */ /* test all kinds of options and the conf file parser */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include <stdlib.h> #include <stdio.h> #include "test_conf_parser_cmd.h" static struct my_args_info args_info; int main (int argc, char **argv) { unsigned int i; int result = 0; struct test_conf_parser_cmd_parser_params *params; /* initialize the parameters structure */ params = test_conf_parser_cmd_parser_params_create(); /* call the command line parser */ if (test_conf_parser_cmd_parser (argc, argv, &args_info) != 0) { result = 1; goto stop; } /* override command line options, but do not initialize args_info, check for required options. NOTICE: we must NOT skip the 0 assignment to initialize, since its default value is 1 and override defaults to 0 while check_required is already set to its default value, 1 */ params->initialize = 0; params->override = 1; /* call the config file parser */ if (test_conf_parser_cmd_parser_config_file (args_info.conf_file_arg, &args_info, params) != 0) { result = 1; goto stop; } printf ("value of required: %s\n", args_info.required_arg); printf ("value of string: %s\n", args_info.string_arg); printf ("value of no-short_given: %d\n", args_info.no_short_given); printf ("value of int: %d\n", args_info.int_arg); printf ("value of float: %f\n", args_info.float_arg); printf ("value of multi-string_given: %d\n", args_info.multi_string_given); for (i = 0; i < args_info.multi_string_given; i++) printf (" value of multi-string: %s\n", args_info.multi_string_arg [i]); printf ("value of multi-string-def_given: %d\n", args_info.multi_string_def_given); for (i = 0; i < args_info.multi_string_def_given; ++i) printf (" value of multi-string-def: %s\n", args_info.multi_string_def_arg [i]); if (!args_info.multi_string_def_given && args_info.multi_string_def_arg [0]) printf ("default value of multi-string-def: %s\n", args_info.multi_string_def_arg [0]); printf ("value of opta: %s\n", args_info.opta_arg); printf ("noarg given %d times\n", args_info.noarg_given); printf ("noarg_noshort given %d times\n", args_info.noarg_noshort_given); printf ("opt-arg given: %d\n", args_info.opt_arg_given); printf ("opt-arg value: %s\n", (args_info.opt_arg_arg ? args_info.opt_arg_arg : "not given")); if (args_info.file_save_given) { if (test_conf_parser_cmd_parser_file_save (args_info.file_save_arg, &args_info) == EXIT_FAILURE) result = 1; else printf ("saved configuration file %s\n", args_info.file_save_arg); } stop: /* deallocate structures */ test_conf_parser_cmd_parser_free (&args_info); free (params); return result; }
So if we use the following config file
# required option required "this is a test" float 3.14 no-short string another
and we run
test_conf_parser like that, we will have
./test_conf_parser -r bar -i 100 --float 2.14 --conf-file test_conf.conf value of required: this is a test value of string: another value of no-short: 1 value of int: 100 value of float: 3.140000
If, instead we call the
test_conf_parser_cmd_parser_configfile with 0
for override argument, we get the following result
value of required: bar value of string: another value of no-short: 1 value of int: 100 value of float: 2.140000
This second example use the second version of the command line parser: first call the configuration file parser and then the command line parser (the command line options will override the configuration file options):
/* test_conf_parser_ov2.c test */ /* test all kinds of options and the conf file parser */ /* differently from test_conf_parser_ov.c, first scan the conf file and then the command line */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include <stdlib.h> #include <stdio.h> #include "test_conf_parser_cmd.h" static struct my_args_info args_info; int main (int argc, char **argv) { struct test_conf_parser_cmd_parser_params *params; /* initialize the parameters structure */ params = test_conf_parser_cmd_parser_params_create(); /* initialize args_info, but don't check for required options NOTICE: the other fields are initialized to their default values */ params->check_required = 0; /* call the config file parser */ if (test_conf_parser_cmd_parser_config_file ("../../tests/test_conf2.conf", &args_info, params) != 0) exit(1); /* override config file options, do not initialize args_info, check for required options. */ params->initialize = 0; params->override = 1; params->check_required = 1; /* call the command line parser */ if (test_conf_parser_cmd_parser_ext (argc, argv, &args_info, params) != 0) exit(1) ; printf ("value of required: %s\n", args_info.required_arg); printf ("value of string: %s\n", args_info.string_arg); printf ("value of no-short_given: %d\n", args_info.no_short_given); printf ("value of int: %d\n", args_info.int_arg); printf ("value of float: %f\n", args_info.float_arg); /* release memory */ test_conf_parser_cmd_parser_free (&args_info); free (params); return 0; }
This is an invocation and its results:
./test_conf_parser_ov2 -r "bar" --float 2.14 -i 100 value of required: bar value of string: another value of no-short: 1 value of int: 100 value of float: 2.140000
If on the above code you substitute
params->override = 1 with
params->check_ambiguity = 1 (see the test file
test_conf_parser_ov4.c), then the following invocation will
generate an error:
./test_conf_parser_ov4 -r "bar" -i 100 ./test_conf_parser_ov4: `--required' (`-r') option given more than once
since the
-r option is specified both in the configuration file
and at the command line.
The generated config file parser function uses the constant
CONFIG_FILE_LINE_SIZE to read each line of the configuration
file. By default this constant is set to
2048 that should be
enough for most applications. If your application uses configuration
files with lines that are longer, you can compile the generated C file
by specifying an explicit value for this constant with the
command line option of
If an option is specified as
multiple, then it can be specified
multiple times at command line. In this case, say the option is
foo, the generated
foo_given field in the args
structure contains the number of times it was specified and the
generated field
foo_arg is an array containing all the values
that were specified for this option.
Notice that if a default value is specified for a multiple option, that value is assigned to the option only if no other value is specified on the command line, i.e., a default value IS NOT always part of the values of a multiple option.
As in the case for standard options, if a multiple option has a
default value, and this is set because no value was specified on the
command line, then the corresponding
<option>_given will still be
initialized to 0. Thus,
<option>_given will effectively inform
you if the user has specified that command line option.
If it is known that a multiple option has a default value, then it can
be safely assumed that the first element of generated array
<option>_arg is always set.
For instance, if the gengetopt file is as follows
# test options that can be given more than once option "string" s "string option" string optional multiple option "int" i "int option" int optional multiple
Then the command line options can be collected like that
Then if this program is called with the following command line options
/* test options that can be given more than once */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include <stdlib.h> #include <stdio.h> #include "test_multiple_cmd.h" static struct gengetopt_args_info args_info; int main (int argc, char **argv) { int i = 0; if (test_multiple_cmd_parser (argc, argv, &args_info) != 0) exit(1) ; for (i = 0; i < args_info.string_given; ++i) printf ("passed string: %s\n", args_info.string_arg[i]); for (i = 0; i < args_info.int_given; ++i) printf ("passed int: %d\n", args_info.int_arg[i]); return 0; }
The output of the program will be
passed string: world passed string: hello passed string: bar passed string: foo passed int: 200 passed int: 100
You can also pass arguments to a multiple option separated by commas (if
you need to actually specify the comma operator as part of the argument
you can escape it with
\), as in the following:
./test_multiple -s"foo","bar","hello" -i100,200 -s "world"
You can specify the number of occurrences of multiple options by using
the following syntax (that must be given after the
number times
number1 times and no more than
number2 times
number times
number times
Here are some examples:
option "string" s "string option" string optional multiple(4)
option "string" s "string option" string optional multiple(1-4)
option "string" s "string option" string optional multiple(-5)
Notice that this is independent from the
required flag.
The parsers generated by gengetopt (indeed the C and header files) are
self-contained and different parsers can be linked in the same program,
without interferences. This is useful, e.g., in cases where a specific
command line option argument has a complex syntax that accepts options
itself according to terminology already defined, i.e., the one handled
getopt_long, see Terminology. Another case when
multiple parsers can be useful is when your command behaves differently
according to a specific command line option.
Obviously there exists only one instance of command line arguments
passed to the
main function (namely the variables
argv) so passing the same arguments to different command
line parsers is likely to generate errors: the different command line
parsers are likely to have different syntaxes for accepted options.
For this reason gengetopt can generate parser functions that take a
string containing the further options to parse, instead of taking an
array. This additional parser will have the parser name and the
_string. If you want these additional parsers to be
generated you have to pass the command line option
-S|--string-parser to gengetopt (see Invoking gengetopt).
The two functions will be:
int <parser_name>_string (const char *cmdline, struct test_first_cmdline_cmd_struct *args_info, const char *prog_name); int <parser_name>_string_ext (const char *cmdline, struct test_first_cmdline_cmd_struct *args_info, const char *prog_name, struct <cmd_parser_name>_params *params);
The second version36 allows you to specify more details about the
parsing, using the
<cmd_parser_name>_params structure, shown in
Parser function additional parameters (this is the same as for
configuration files, thus we refer to that section for the details of
the two functions and default values, see Configuration files).
Of course, these functions can be used in general to simulate the invocation of a program with specific command line options (stored in the first string argument), or in general to parse options that are all stored in a string (instead of a vector).
The first argument of these parsers is a string containing the options
to parse (remember that this must respect the option format handled by
getopt_long, see Terminology). The second one is the
pointer to the struct that will be filled with passed options and
arguments, as usual. The third option is the program name: this will
be used when errors have to be printed. This last argument can be
null: in this case, the first element of the first string argument is
considered the program name.
Let's show these functionalities with an example. Consider a program that accepts two command line options (required in this case):
# test for multiple parsers, this is the main file # test_main_cmdline_cmd.ggo option "first-cmd" F "the first command line to parse" required \ typestr="first command" string multiple option "second-cmd" S "the second command line to parse" required \ typestr="second command" string multiple
These two options accept strings as argument that in turn are considered command line arguments, according to specific syntaxes. The first one is:
# test for multiple parsers, this is the first command line file # test_first_cmdline_cmd.ggostr option "option-a" a "option a of the first command line to parse" optional int option "multi" M \ "multiple option of the first command line to parse" \ optional string multiple
and the second one is:
# test for multiple parsers, this is the second command line file # test_second_cmdline_cmd.ggostr option "option-a" a "option a of the second command line to parse" \ optional string option "option-b" b "option a of the second command line to parse" \ optional string option "my-multi" M \ "multiple option of the second command line to parse" \ optional string multiple
These last two files are processed with gengetopt using the
--string-parser. Let's put everything together in this main
#ifdef HAVE_CONFIG_H #include "config.h" #endif #include <stdio.h> #include <stdlib.h> #include "test_main_cmdline_cmd.h" #include "test_first_cmdline_cmd.h" #include "test_second_cmdline_cmd.h" int main(int argc, char **argv) { struct gengetopt_args_info main_args_info; struct test_first_cmdline_cmd_struct first_args_info; struct test_second_cmdline_cmd_struct second_args_info; int exit_code = 0; unsigned int i, j; if (test_main_cmdline_cmd_parser (argc, argv, &main_args_info) != 0) { exit_code = 1; return exit_code; } for (j = 0; j < main_args_info.second_cmd_given; ++j) { printf("second cmdline: %s\n", main_args_info.second_cmd_arg[j]); if (test_second_cmdline_cmd_parser_string (main_args_info.second_cmd_arg[j], &second_args_info, argv[0]) == 0) { if (second_args_info.option_a_given) printf(" --option-a: %s\n", second_args_info.option_a_arg); if (second_args_info.option_b_given) printf(" --option-b: %s\n", second_args_info.option_b_arg); for (i = 0; i < second_args_info.my_multi_given; ++i) printf(" --my-multi: %s\n", second_args_info.my_multi_arg[i]); test_second_cmdline_cmd_parser_free (&second_args_info); } } for (j = 0; j < main_args_info.first_cmd_given; ++j) { printf("first cmdline: %s\n", main_args_info.first_cmd_arg[j]); if (test_first_cmdline_cmd_parser_string (main_args_info.first_cmd_arg[j], &first_args_info, argv[0]) == 0) { if (first_args_info.option_a_given) printf(" --option-a: %d\n", first_args_info.option_a_arg); for (i = 0; i < first_args_info.multi_given; ++i) printf(" --multi: %s\n", first_args_info.multi_arg[i]); test_first_cmdline_cmd_parser_free (&first_args_info); } } test_main_cmdline_cmd_parser_free (&main_args_info); return exit_code; }
Notice that in the
for loops we always free the elements of the
argument structures in order to avoid memory leaks.
Now if you can run this program as follows (notice that we use the comma
separated arguments for multiple option arguments but we escape it with
\ because otherwise, e.g., 200 and 300 would be intended as
further arguments of
--first-cmd instead of
--multi, see
Multiple Options):
./test_multiple_parsers \ --first-cmd="-M400 -a10 --multi 100\,200\,300" \ --second-cmd="-a20 -b10 --my-multi=a\,b\,c\,d\,e\,f" \ -F"-M500 -M600" -S"--my-multi g" second cmdline: -a20 -b10 --my-multi=a,b,c,d,e,f --option-a: 20 --option-b: 10 --my-multi: a --my-multi: b --my-multi: c --my-multi: d --my-multi: e --my-multi: f second cmdline: --my-multi g --my-multi: g first cmdline: -M400 -a10 --multi 100,200,300 --option-a: 10 --multi: 400 --multi: 100 --multi: 200 --multi: 300 first cmdline: -M500 -M600 --multi: 500 --multi: 600
If you use gengetopt to generate C functions for parsing command line
arguments you have to know that these generated functions use
getopt_long to actually read the command line and parsing it.
This function is typically part of the standard C library, but some
implementations may not include it. If you want your program to be
portable on several systems, and be compilable with many C compilers,
you can rely on one of the following solutions.
getopt_long code into the generated parser
Since version 2.17, gengetopt can include into the generated C parser
file the code of
getopt_long, so that the include code will be
used to actually parse the command line arguments, instead of that taken
from the C library.
This solution is actually quite easy, since you only need to specify the
command line option
--include-getopt (see Invoking gengetopt), but it has two main drawbacks:
of the C library
It is up to you to choose between this and the automake/autoconf based solution.
Actually, this solution has the advantage that your program won't behave
strangely when used with another implementation of
I prefer the automake/autoconf based solution, as described in Use automake/autoconf, in particular the one described in Use Gnulib, which is also the one I adopt for gengetopt itself.
Autoconf and Automake are great tools to generate a configure script
that automatically checks for the configuration of your system and for
possible missing functions required to compile your program. However,
in case of detected missing functions, your program must be able to
provide a replacement for such functions. In the next sections we
describe two mechanisms for including the (possible) missing code for
getopt_long and for checking its presence with automake/autoconf.
Since version 2.19, gengetopt itself uses the first mechanism.
Since version 2.19 I also started to use Gnulib - The GNU Portability Library37, "a central location for common GNU code, intended to be shared among GNU packages". Gnulib provides an easy and smooth way to add to your package sources the sources of functions that you want to check during configure. It will also handle the checks for these functions in the configure script, and in case they're not in your system (or they're present but with some missing features) it compiles their sources into a library (that you will need to link your program to, as illustrated in the following).
Once you retrieved gnulib (for the moment it is available only through git, see the home page), you can invoke 'gnulib-tool --import' that will copy source files, create a Makefile.am to build them, generate a file gnulib-comp.m4 with Autoconf M4 macro declarations used by configure.ac, and generate a file gnulib-cache.m4 containing the cached specification of how Gnulib is used. In particular, you must specify the modules you want to import, and in our case, it is getopt:
gnulib-tool --import getopt
By default, the source code is copied into lib/ and the M4
macros in m4/. You can override these paths by using
--source-base=DIRECTORY and
For instance, gengetopt uses
gl and
gl/m4, respectively.
We will use these directories in the rest of this section.
You must ensure Autoconf can find the macro definitions in
gnulib-comp.m4. Use the
ACLOCAL_AMFLAGS specifier in your
top-level Makefile.am file (and the first time you run
aclocal you have to use the
-I as well); for instance, in
the case of gengetopt we have:
ACLOCAL_AMFLAGS = -I gl/m4
You are now ready to call the M4 macros in
gnulib-comp.m4 from
configure.ac. The macro
gl_EARLY must be called as soon
as possible after verifying that the C compiler is working.
Typically, this is immediately after
AC_PROG_CC, as in:
... AC_PROG_CC gl_EARLY ...
The core part of the gnulib checks are done by the macro
gl_INIT. Place it further down in the file, typically where
you normally check for header files or functions. For example:
... # For gnulib. gl_INIT ...
gl_INIT will in turn call the macros related with the gnulib
functions, be it specific gnulib macros. So there is no need to call
those macros yourself when you use the corresponding gnulib modules.
You must also make sure that the gnulib library is built. Add the
Makefile in the gnulib source base directory to
AC_CONFIG_FILES, as in:
AC_CONFIG_FILES(... gl/Makefile ...)
You must also make sure that
make will recurse into the gnulib
directory. To achieve this, add the gnulib source base directory to a
SUBDIRS Makefile.am statement, as in:
SUBDIRS = gl
Finally, you have to add compiler and linker flags in the appropriate source directories, so that you can make use of the gnulib library. Since the 'getopt' module copies files into the build directory, top_builddir/gl is needed as well as top_srcdir/gl. For example:
... AM_CPPFLAGS = -I$(top_srcdir)/gl -I$(top_builddir)/gl ... LDADD = gl/libgnu.a ...
Don't forget to
#include the various header files. In this
example, you would need to make sure that '#include "getopt.h"' is
evaluated when compiling all source code files, that want to make use of
getopt or
getopt_long. If you simply use the files
generated by gengetopt, you won't need include this header though, since
it is already handled by the generated files.
Every now and then, check whether there are updates in the Gnulib
modules, and if the modules you use (e.g.,
getopt) are upgraded,
please remember to also update your files, simply by running:
gnulib-tool --update
We refer to Gnulib documentation for further explanations and features.
NOTICE: this was the procedure used by gengetopt itself up to version 2.18. We suggest now to use the procedure described in Use Gnulib, since the files described in the following might not be kept up-to-date.
We provide C files that actually implement
getopt_long function:
getopt.c getopt1.c and gnugetopt.h. You'll find
these files in the <install prefix>/share/gengetopt directory
where <install prefix> is the one you specified during
compilation. If no prefix had been specified, /usr/local is the
default. If you downloaded gengetopt in binary form prefix will
probably be /usr/local or /usr.
You can rename gnugetopt.h to getopt.h and then simply compile these files and link them to the executable of you program. However, if you use automake and autoconf here's a more elegant solution: you should download the file adl_func_getopt_long.m4 you find at this site:
and add its contents to your acinclude.m4. You can find this macro also in the acinclude.m4 in the sources of gengetopt.
This macro checks if getopt_long function is in C library;
if it is not then it adds getopt.o and getopt1.o to the objects files
that will be linked to your executable (
Then in Makefile.am of your source directory you have to add the contents
LIBOBJS to the
LDADD of the program that has to use getopt_long;
e.g., if the program foo has to use getopt_long, you have to add
the following line
foo_LDADD = @LIBOBJS@
Now these files will be compiled and linked to your program only if necessary.
Moreover you have to add getopt.c getopt1.c and
gnugetopt.h to your distribution. Note that it is not necessary
to put these file names among the
foo_SOURCES contents), but you have to
add gnugetopt.h to
EXTRA_DIST = gnugetopt.h
You may want to take a look at gengetopt's configure.in and src/Makefile.am: they both use the techniques described here.
If you find a bug in gengetopt, please use the Savannah web interface
Include the version number, which you can find by running 'gengetopt --version'. Also include in your message the output that the program produced and the output you expected.
If you have other questions, comments or suggestions about gengetopt, contact the author via electronic mail (find the address at http://www.lorenzobettini.it). The author will try to help you out, although he may not have time to fix your problems.
The list of to-dos in the TODO.
It seems that
getopt_long, at least the version in the GNU
library, if invoked with different
argv arrays, might access
memory in a bad way leading to crashes or unexpected behaviors. This
happens because it keeps pointers to locations of the previous arrays
if not initialized each time by setting
optind =
Unfortunately this initialization behavior seems to be part only of
the implementation of GNU library and actually it is not documented
(you can see it by taking a look into the source of getopt.c);
other implementations of
getopt_long might not be affected by
this problem; alternatively, as reported by a user,
optind = 0
leads some
getopt_long implementations to consider the program
name as a command line option (since it is in position 0), which is
bad anyway!
Probably this is usually not a problem since you usually parse only the
command line, thus you only invoke the command line parser only once,
and only with one instance of array (i.e., the
argv passed to
main). However, it can lead to problems when you use advanced
features, as in the case of configuration file parsing (see
Configuration files) and multiple parsers (see String Parsers and Multiple Parsers).
The parser generated by gengetopt checks whether the program name was
actually considered a command line option, and in that case it removes
it from the collected command line options; thus, this
issue should not come up anyway. In case you still don't feel
comfortable, you can include a correct
getopt_long implementation
in the generated parser, so that you can be sure you will always use the
same implementation of
getopt_long (Include the getopt_long code into the parser).
The following mailing lists are available:
help-gengetopt at gnu dot org
for generic discussions about the program and for asking for help about it (open mailing list), http://mail.gnu.org/mailman/listinfo/help-gengetopt
info-gengetopt at gnu dot org
for receiving information about new releases and features (read-only mailing list), http://mail.gnu.org/mailman/listinfo/info-gengetopt.
If you want to subscribe to a mailing list just go to the URL and follow the instructions, or send me an e-mail and I'll subscribe you.
I'll describe new features in new releases also on my blog, at this URL:
--arg-struct-name: Invoking gengetopt
--conf-parser: Invoking gengetopt
--default-optional: Invoking gengetopt
--default-optional: Basic Usage
--detailed-help: Basic Usage
--full-help: Basic Usage
--func-name: Invoking gengetopt
--gen-version: Invoking gengetopt
--header-output-dir: Invoking gengetopt
--include-getopt: Include the getopt_long code into the parser
--include-getopt: Invoking gengetopt
--long-help: Invoking gengetopt
--no-handle-error: Invoking gengetopt
--no-handle-help: Invoking gengetopt
--no-handle-version: Invoking gengetopt
--no-help: Invoking gengetopt
--no-version: Invoking gengetopt
--output-dir: Invoking gengetopt
--show-full-help: Invoking gengetopt
--show-help: Invoking gengetopt
--show-required: Invoking gengetopt
--show-version: Invoking gengetopt
--src-output-dir: Invoking gengetopt
--string-parser: Invoking gengetopt
--unamed-opts: Invoking gengetopt
-C,--conf-parser: Configuration files
-h,--detailed-help: Basic Usage
-h,--help: Basic Usage
-S,--string-parser: String Parsers and Multiple Parsers
-V,--version: Basic Usage
[1] Since version 2.22.4 of Gengetopt the CVS repository was dismissed in favor of Git (http://git-scm.com/).
[2] http://www.gnu.org/software/autoconf
[3] http://www.gnu.org/software/automake
[4] http://www.gnu.org/software/libtool
[5] http://www.gnu.org/software/gnulib
[6] Since version 2.19.
[7] Since version 2.19.
[8] Since version 2.18
[9] Since version 2.22.
[10] Since version 2.22 the type can be specified
[11] Since version 2.20.
[12] Since version 2.15.
[13] Since version 2.16.
[14] This is true since version 2.19. Before this version, strings were not allowed to spawn more than one line.
[15] Since version 2.19.
[16] This holds since version 2.15: in previous versions the option specifications had to be given in a fixed order.
[17] Before version 2.22 neither
--help was added
and you had to handle the help option manually
[18] Since version 2.16.
[19] Since version 2.22.
[20] Since version 2.18.
[21] as it was up to version 2.22.2 of gengetopt.
[22] This is taken from the comments in getopt.in.h of gnulib.
[23] Since
version 2.22 this field is of type
unsigned int instead of
int for uniformity with multiple options.
[24] The
<option>_orig was introduced in the release
[25] These strings and the
<option>_help were introduced in the release 2.17.
[26] This function was introduced in the release 2.14.
[27] Introduced in version 2.22, thanks to Papp Gyozo.
[28] Since version 2.17.
[29] Since version 2.22.3.
[30] Since version 2.22.
[31] Since version 2.21.
[32] Introduced in version 2.22
[33] The
<cmd_parser_name>_params_init was
introduced in version 2.21, but it used to initialize all its fields to
0, which does not make much sense, since it's more helpful to have the
fields initialized to their default values; in order not to silently
break the semantics of previous code, the (void argument) creation
function is now called
<cmd_parser_name>_params_create and
<cmd_parser_name>_params_init is now a procedure that initializes
a passed pointer to the structure. This will make previous code not
compilable, since the signature of
has changed; hopefully, this will force the programmer to realize that
something has changed. I'm sorry for the (hopefully little) problems
this change might imply.
[34] The
previous function
<cmd_parser_name>_configfile — notice the
absence of the
_ — is deprecated and should be no longer used,
since it might be removed in the future releases.
[35] The previous function
<cmd_parser_name>2 — notice the
2 — is deprecated and
should be no longer used, since it might be removed in the future
[36] The previous function
<cmd_parser_name>_string2 — notice the
2 — is
deprecated and should be no longer used, since it might be removed in
the future releases.
[37] http://www.gnu.org/software/gnulib
optind is the global variable in getopt
implementation that is the index in ARGV of the next element to be
scanned. This is used for communication to and from the caller and
for communication between successive calls to


text:
They dreamed, they entered, they trained ... and they finished!
It was everything I anticipated and more, said Leah Fein of the 2012 Hardrock 100 Endurance Run. I ended up getting engaged at the finish, which greatly added to the best day and a half of my life.
Feins training panned out perfectly for the race that started and finished in Silverton with more than 30,000 feet of elevation gain.
I spent three days a week in Silverton training on the course for two months leading up to the race, she said. That specific training was key to learn the course like the back of my hand and to condition my body for the extreme conditions of the San Juan Mountains.
Pleased with her time, Fein felt everything went better than anticipated. She thought she might suffer more and be burned out on running. On the contrary, though, she would love to run it again.
Ive got the Hardrock bug bad, she said.
Drew Gunn had the race he dreamed of.
I was surprised that I never really had a low point, Gunn said. Even when I was hurting, I was still enjoying being out there.
Aside from wishing he had more time, he wouldnt change much about his preparation for this race.
Training for ultras is very time-consuming, and just running, recovery, yoga and eating could be a full-time job for me, Gunn said.
He also stressed the importance of training on the course, if possible.
Knowing the lay of the land can be very helpful, he said. Learn to power-hike efficiently. Unless you plan on being top 10, you wont be running uphill much at all, but fast hiking can get you a pretty good time.
Expecting to feel lousy near the end, he was surprised at how good he felt the last 20 miles.
I have to credit my pacers for doing a fantastic job of keeping me psyched, Gunn said. That and having my parents there had a tremendously positive effect on my mood throughout the race.
Megan Finnesy gushed about her experience.
I loved being out on the course with all the other Hardrockers, and going in and out of the amazing aid stations, it just kept me going, Finnesy said.
At the Sherman aid station, she felt a surge and came alive.
I was able to push the last 28 miles, I passed 15 people from Sherman to the finish.
Having family and friends around throughout the race was a plus for Finnesy, as well.
I felt so blessed to have my dad and sister and a bunch of friends there, she said. It was so much more than I could have imagined. There has been nothing like it.
In addition to running Hardrock for the personal gratification, Finnesy wanted to support Big Brothers Big Sisters, a cause that is important to her. She sought pledges for every mile and every 13,000-foot-plus pass she climbed and raised $2,303.
Strengthening the courage, confidence and leadership skills of kids is important to me, Finnesy said.
For these three Durango first-time Hardrock finishers, the dream became reality and Hardrock fever surely will lure them back.
Reach Marjorie Brinton at firstname.lastname@example.com.

subset: commoncrawl