GNU Gengetopt 2.8
/December 30th, 2002/
This program generates a C function that uses /getopt_long/ function to
parse the command line options, to validate them and fills a /struct/ .
Thus your program can now handle 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. 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 is *free software*. Please see the file LICENSE and COPYING
for details.
Notice that: Use of gengetopt _does not impose any particular license on
the generated code: the code generated is not under any license_.
For documentation, please read this file.
gengetopt is perfect if you are too lazy (like me) to write all stuff
required to call getopt_long, and when you have a
program and wish it took options.
Generated code works if you use /GNU Autoconf/ or /GNU Automake/ .
Gengetopt has originally been written by *Roberto Arturo Tena Sanchez*
<arturo@directmail.org <mailto:arturo@directmail.org>>, and currently
maintained by *Lorenzo Bettini *<bettini@gnu.org <mailto:bettini@gnu.org>>.
Gengetopt is a GNU <http://www.gnu.org> program and its main home page
is at GNU site:
http://www.gnu.org/software/gengetopt/gengetopt.html ,
Download
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
(bettini@gnu.org <mailto:bettini@gnu.org> ) and I can send them to you.
You may also want to check the /md5sum/ of the archives, which are also
digitally signed by me (/Lorenzo Bettini/) with /GNU gpg/
(http://www.gnupg.org). My GPG public key can be found at my home page
(see at the end of this doc).
You can also get the patches, if they are available for a particular
release (see below <#Patching%20from%20a%20previous%20version> for
patching from a previous version).
Anonymous CVS Access
This project's CVS repository can be checked out through anonymous
(pserver) CVS with the following instruction set. When prompted for a
password for anoncvs, simply press the Enter key.
cvs -d:pserver:anoncvs@subversions.gnu.org:/cvsroot/gengetopt login
cvs -z3 -d:pserver:anoncvs@subversions.gnu.org:/cvsroot/gengetopt co gengetopt
Further instructions can be found at the address:
http://savannah.gnu.org/projects/gengetopt .
Changes in this release
* see NEWS file for a summary of new features in this release and
* see ChangeLog for the complete list of changes sources
Installation
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:
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 'make install'.
You can also run some tests by issuing 'make check'.
Files will be installed in the following directories:
* Executables -> /prefix/bin
* Docs -> /prefix/share/doc/gengetopt
* Man pages -> /prefix/man
* Examples -> /prefix/share/doc/gengetopt/examples
* Util files -> /prefix/share/gengetopt
Default value for prefix is /usr/local but you may change it with
--prefix option to configure (see above).
What you need to build gengetopt
*Actually you need nothing more than a Unix C/C++ compiler.*
/getopt_long/ function is usually in the standard C library, but there
may be some C libraries which don't include it; in this case you have to
link the program that uses the file generated by gengetopt with the
files /getopt.c/ and /getopt1.c/ and include /getopt.h/ in your project.
You may also need to link /alloca.c./We obviously provide these files in
the utility files directory (/prefix/share/gengetopt). These files are
part of the GNU C library. You may want to take a look at /getopt/ man
page <man_getopt.html>. Read also no_getopt_long.txt. for instuctions on
how to check if /getopt_long/ and /alloca/ are part of the library and
how to deal with their lacking (using /autoconf/ and /automake/).
gengetopt has been developed under Linux, using *gcc*, and *bison*
(yacc) and *flex* (lex), and ported under Windows with *Cygnus C/C++*
compiler, available at http://www.cygnus.com/. I used the excellent GNU
*Autoconf* and *Automake*. I also used *Autotools
*(ftp://ftp.ugcs.caltech.edu/pub/elef/autotools ) which creates a
starting source tree (according to GNU standards) with autoconf,
automake starting files, and *getopt_long* (for command line parsing).
Moreover /Gengen/ (http://www.lorenzobettini.it/software/gengen/ ) is
used for automatically generating the code that generates the command
line parser.
Actually, unless you want to develop gengetopt, you don't need all these
tools to build gengetopt because I provide generated sources; you don't
need neither bison (yacc) nor flex (lex), for the same reason. Actually
programs that use lex generated files need to link with library /libfl
/(or / libl /for lex); anyway configuration phase can discover if this
library is missing and in that case it sets the program to link with a
source file I provide. This hack works for flex: I don't know about lex
generated scanners. But, again, this is a problem only if you develop
gengetopt and you use lex.
Should you want to act on the generated code you may want to download
/Gengen/ that speeds up this part
(http://www.lorenzobettini.it/software/gengen/ ).
Patching from a previous version
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 will do).
Usage (/a little tutorial/)
The command line options, which have to be handled by gengetopt
generated function, are specified in a file (typically with /.ggo/
extension). This file consist in lines of sentences with the following
formats:
package <packname>
version <version>
option <long> <short> <desc> <argtype> {default="<default value>"} <required> {multiple}
option <long> <short> <desc> flag <onoff>
option <long> <short> <desc> no
Where:
*packname*
Double quoted string.
*version*
Double quoted string.
*purpose*
What the program does (even on more than one line), it will be
printed with the help. Double quoted string.
*long*
The long option, a double quoted string with upper and lower
case chars, digits, '-' and '.'. No spaces allowed. The name of
the variables generated to store arguments are long options
converted to be legal C variable names. This means, '.' and '-'
are both replaced by '_'. '_arg' is appended, or '_flag' for a flag.
*short*
The short option, a single upper or lower case char, or a
digit. If a '-' is specified, then no short option is considered for
the long option (thus long options with no associated short options
are allowed).
*desc*
Double quoted string with upper and lower case chars, digits,
'-', '.' and spaces. First character must not be a space.
*argtype*
string, int, short, long, float, double, longdouble or longlong.
*default*
an optional default value for the option. The value must always be
specified as a double quoted string.
*required*
yes or no.
*multiple*
If this flag is specified then this option can be specified more
than once at command line; all the values for this option are stored
in an array. See multiple options <#multiple> in the Advanced
Features section.
*onoff*
on or off. This is the state of the flag when the program starts. If
user specifies the option, the flag toggles.
The third type of option is used when the option does not take any
argument. It must not be required.
Comments begins with '*#*' in any place of the line and ends in the end
of line.
Here's an example of such a file (the file is called /sample1.ggo/)
# file sample1.ggo
option "str-opt" s "A string option" string no
option "my-opt" m "Another integer option" int no
option "int-opt" i "A int option" int yes
option "flag-opt" - "A flag option" flag off
option "funct-opt" F "A function option" no
option "long-opt" - "A long option" long no
option "def-opt" - "A string option with default" string
default="Hello" no
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 as
*.c, foo*.? and so on).
In cmdline1.h you'll find the generated C struct:
//* cmdline1.h */
/* File autogenerated by gengetopt version 2.6 */
/*#ifndef* _cmdline1_h
*#define* _cmdline1_h
*#ifdef* __cplusplus
*extern* "C" {
*#endif* //* __cplusplus */
/* Don't define PACKAGE and VERSION if we use automake. */
/*#if* defined PACKAGE
*# undef* PACKAGE
*#endif
#define* PACKAGE "sample1"
*#if* defined VERSION
*# undef* VERSION
*#endif
#define* VERSION "2.0"
*struct* gengetopt_args_info {
char * str_opt_arg; //* A string option. */
/ int my_opt_arg; //* Another integer option. */
/ int int_opt_arg; //* A int option. */
/ int flag_opt_flag; //* A flag option (default=off). */
/ long long_opt_arg; //* A long option. */
/ char * def_opt_arg; //* A string option with default (default='Hello'). */
/ int help_given ; //* Whether help was given. */
/ int version_given ; //* Whether version was given. */
/ int str_opt_given ; //* Whether str-opt was given. */
/ int my_opt_given ; //* Whether my-opt was given. */
/ int int_opt_given ; //* Whether int-opt was given. */
/ int flag_opt_given ; //* Whether flag-opt was given. */
/ int funct_opt_given ; //* Whether funct-opt was given. */
/ int long_opt_given ; //* Whether long-opt was given. */
/ int def_opt_given ; //* Whether def-opt was given. */
/ char **inputs ; //* unamed options */
/ unsigned inputs_num ; //* unamed options number */
/} ;
int *cmdline_parser* (int argc, char * *const* *argv, *struct* gengetopt_args_info *args_info);
void *cmdline_parser_print_help*(void);
void *cmdline_parser_print_version*(void);
*#ifdef* __cplusplus
}
*#endif* //* __cplusplus */
/*#endif* //* _cmdline1_h *//
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.
And here's how this function 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 */
/*#include* <iostream.h>
*#include* "stdlib.h"
*#include* "cmdline1.h"
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 ;
cout << args_info.def_opt_arg << "! ";
cout << "Have a nice day! :-)" << endl ;
*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 'What you need to build gengetopt <#build%20gengetopt>' section).
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!
If you're curious you may want to take a look at the generated C file
<cmdline1.c.html>.
You may find other examples in /prefix/share/doc/gengetopt.
Advanced features
Group options
It is also possible /to group/ options; options belonging to a group are
considered mutual exclusive. 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 mutual exclusive) and the
/group/to which the option belongs has to be specified.
defgroup "<group name>" {yes}
option <long> <short> <desc> <argtype> group="<group name>"
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 "grp2"
defgroup "grp1" yes
groupoption "opta" a "string a" group="grp1"
groupoption "optb" b "string b" group="grp1"
groupoption "optc" c "string c" group="grp2"
groupoption "optd" d "string d" group="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
gengetopt: 0 options of group grp1 were given. One is required
$ ./test_groups -a OK
$ ./test_groups -a -b
gengetopt: 2 options of group grp1 were given. One is required
$ ./test_groups -a -c OK
$ ./test_groups -a -c -d
gengetopt: 2 options of group grp2 were given. At most one is required
Config files
It is often useful to specifiy 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 / --conf-parser/ is given to gengetopt, apart from the
standard command line option parser, also this additional parser is
generated (its name is /<commandline_parser>_configfile/):
int
<cmd_parser_name>_configfile (char * const filename,
struct gengetopt_args_info *args_info,
int override);
The config file has the following simple syntax: lines starting with /#/
are considered comments and:
* <option_name> {<option_val>} means that /option_name/ is given,
and if it accepts an argument, then its value is /option_val/
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 *//
*#include* <stdlib.h>
*#include* <stdio.h>
*#include* "test_conf_parser_cmd.h"
*static* *struct* gengetopt_args_info args_info;
int
*main* (int argc, char **argv)
{
*if* (*test_conf_parser_cmd_parser* (argc, argv, &args_info) != 0)
*exit*(1) ;
*if* (*test_conf_parser_cmd_parser_configfile*
(args_info.conf_file_arg, &args_info, 1) != 0) /// override cmd options/
*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: %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);
*return* 0;
}
So if we use the config file (/test_conf.conf/)
# required option
required "foo"
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 --conf-file test_conf.conf
value of required: "foo"
value of string: another
value of no-short: 1
value of int: 100
value of float: 3.140000
Multiple options
If an option is specified as multiple, then it can be specified multiple
times at command line. In this case, say the option is called 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.
For instance, if the gengetopt file is as follows
# test options that can be given more than once
option "string" s "string option" string no multiple
option "int" i "int option" int no multiple
Then the command line options can be collected like that
//* test_multiple.c test *//
//* test options that can be given more than once *//
*#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;
}
Then if this program is called with the following command line options
./test_multiple -s "foo" -s "bar" -s "hello" -i 100 -i 200 -s "world"
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
Warning for Windows users
If you run Windows, please remember that DOS shell does not translate
wildcards, and thus the previous test which uses '*.h' will not work.
Options
This is the output of /gengetopt --help/:
$ gengetopt --help
gengetopt 2.8
Purpose:
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
-V --version Print version and exit
-iSTRING --input=STRING input file (default std input)
-fSTRING --func-name=STRING name of generated function (default='cmdline_parser')
-FSTRING --file-name=STRING name of generated file (default='cmdline')
-l --long-help long usage line in help
-u --unamed-opts accept filenames
--no-handle-help do not handle --help|-h automatically
--no-handle-version do not handle --version|-V automatically
--no-handle-error do not exit on errors
--conf-parser generate a config file parser
Maintained by Lorenzo Bettini <bettini@gnu.org>
Report bugs to <bug-gengetopt@gnu.org>
The options should be clear; in particular:
* if no --/func-name/ is given, /cmdline_parser/ is taken by default;
* with /--long-help/ option, the "Usage" line reports all the
options; this may be unpleasant if options are many;
* with /--unamed-opts/ we can accept also options without a name,
which, in most case, means that we can pass many file names to the
program (see the example above when we call /sample1 *.h/).
* if /--no-handle-help/ (/--no-handle-version/) is given the command
line /--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>_print_version/), where
/<parser-name>/ is the name specified with /---func-name/ or the
default /cmdline_parser/.
* if /--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 non 0, the program can
print a help message, as gengetopt itself does in case of an error
(try it!).
You may have already guessed it: _gengetopt uses gengetopt itself_ for
command line options, and this is its specification file:
purpose "This program generates a C function that uses getopt_long function
to parse the command line options, validate them and fill a struct."
option "input" i "input file. default std input" string no
option "func-name" f "name of generated function" string default="cmdline_parser" no
option "file-name" F "name of generated file" string default="cmdline" no
option "long-help" l "long usage line in help" no
option "unamed-opts" u "accept filenames" no
option "no-handle-help" - "do not handle --help|-h automatically" no
option "no-handle-version" - "do not handle --version|-V automatically" no
option "no-handle-error" - "do not exit on errors" no
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 screen:
$ ./gengetopt --zzzz
./gengetopt: unrecognized option `--zzzz'
Run gengetopt --help to see the list of options.
Credits
See THANKS file :-)
Feedback
Tell us if you like this software :-)
Actually we want to extend it, so if you have some ideas... The most
import one will be to make gengetopt more customizable :-)
Please send all bug reports by electronic mail to:
bug-gengetopt@gnu.org <mailto:bug-gengetopt@gnu.org>
Mailing Lists
The following mailing lists are available:
* help-gengetopt@gnu.org <mailto:help-gengetopt@gnu.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@gnu.org <mailto:info-gengetopt@gnu.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.
*Lorenzo Bettini*
http://www.lorenzobettini.it
<bettini@gnu.org <mailto:bettini@gnu.org>>. *Roberto Arturo Tena Sanchez*
http://arturo.directmail.org
<arturo@directmail.org <mailto:arturo@directmail.org>>,
gengetopt is free software. See the file LICENSE and COPYING for copying
conditions. Anyway we won't get offended if you send us a postcard :-)
C/C++ files are formatted with /GNU Source-highlight/
(http://www.gnu.org/software/src-highlite/ ) by Lorenzo Bettini.
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Please send comments on these web pages to /webmasters@gnu.org
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Copyright (C) 2001 Free Software Foundation, Inc., 59 Temple Place -
Suite 330, Boston, MA 02111, USA
Verbatim copying and distribution of this entire article is permitted in
any medium, provided this notice is preserved.
Updated:9 Jan 2001 mhw
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