getopt.h File Reference

Parse command-line options. More...

#include <stddef.h>

Go to the source code of this file.

Data Structures
struct	option
	A long option, as used for getopt_long(). More...
Enumerations
enum	getopt_argument_requirement { no_argument = 0, required_argument = 1, optional_argument = 2 }
Functions
	FILE_LICENCE (GPL2_OR_LATER)
int	getopt_long (int argc, char *const argv[], const char *optstring, const struct option *longopts, int *longindex)
	Parse command-line options.
static int	getopt (int argc, char *const argv[], const char *optstring)
	Parse command-line options.
static void	reset_getopt (void)
	Reset getopt() internal state.
Variables
char *	optarg
	Option argument.
int	optind
	Current option index.
int	nextchar
	Current option character index.
int	optopt
	Unrecognised option.

---

Detailed Description

Parse command-line options.

Definition in file getopt.h.

---

Enumeration Type Documentation

enum getopt_argument_requirement

Enumerator:

no_argument	Option does not take an argument.
required_argument	Option requires an argument.
optional_argument	Option may have an argument.

Definition at line 14 of file getopt.h.

                                 {
        /** Option does not take an argument */
        no_argument = 0,
        /** Option requires an argument */
        required_argument = 1,
        /** Option may have an argument */
        optional_argument = 2,
};

---

Function Documentation

FILE_LICENCE

(

GPL2_OR_LATER

)

int getopt_long	(	int	argc,
		char *const	argv[],
		const char *	optstring,
		const struct option *	longopts,
		int *	longindex
	)

Parse command-line options.

Parameters:

	argc	Argument count
	argv	Argument list
	optstring	Option specification string
	longopts	Long option specification table

Return values:

	longindex	Index of long option (or NULL)
	option	Option found, or -1 for no more options

Note that the caller must arrange for reset_getopt() to be called before each set of calls to getopt_long(). In Etherboot, this is done automatically by execv().

Definition at line 224 of file getopt.c.

References option::has_arg, match_long_option(), match_short_option(), option::name, nextchar, no_argument, optind, optopt, and printf().

Referenced by dhcp_exec(), gdbstub_exec(), getopt(), ifcommon_exec(), imgargs_exec(), imgexec_exec(), imgfetch_core_exec(), imgfree_exec(), imgload_exec(), imgstat_exec(), pxebs_exec(), route_exec(), and sanboot_exec().

                                                                  {
        const char *opttext = argv[optind];
        const struct option *longopt;
        int shortopt;
        enum getopt_argument_requirement has_arg;
        int option;

        /* Check for end of argv array */
        if ( optind >= argc )
                return -1;

        /* Check for end of options */
        if ( *(opttext++) != '-' )
                return -1;

        /* Check for long options */
        if ( *(opttext++) == '-' ) {
                for ( longopt = longopts ; longopt->name ; longopt++ ) {
                        if ( ! match_long_option ( argc, argv, opttext,
                                                   longopt, &option ) )
                                continue;
                        if ( longindex )
                                *longindex = ( longopt - longopts );
                        return option;
                }
                optopt = '?';
                printf ( "Unrecognised option \"--%s\"\n", opttext );
                return '?';
        }

        /* Check for short options */
        if ( nextchar < 1 )
                nextchar = 1;
        opttext = ( argv[optind] + nextchar );
        while ( ( shortopt = *(optstring++) ) ) {
                has_arg = no_argument;
                while ( *optstring == ':' ) {
                        has_arg++;
                        optstring++;
                }
                if ( match_short_option ( argc, argv, opttext, shortopt,
                                          has_arg, &option ) ) {
                        return option;
                }
        }
        optopt = *opttext;
        printf ( "Unrecognised option \"-%c\"\n", optopt );
        return '?';
}

static int getopt	(	int	argc,
		char *const	argv[],
		const char *	optstring
	)			[inline, static]

Parse command-line options.

Parameters:

	argv	Argument count
	argv	Argument list
	optstring	Option specification string

Return values:

option

Option found, or -1 for no more options

See getopt_long() for full details.

Definition at line 70 of file getopt.h.

References getopt_long(), and NULL.

                                                   {
        static const struct option no_options[] = {
                { NULL, 0, NULL, 0 }
        };
        return getopt_long ( argc, argv, optstring, no_options, NULL );
}

static void reset_getopt

(

void

)

[inline, static]

Reset getopt() internal state.

Due to a limitation of the POSIX getopt() API, it is necessary to add a call to reset_getopt() before each set of calls to getopt() or getopt_long(). This arises because POSIX assumes that each process will parse command line arguments no more than once; this assumption is not valid within Etherboot. We work around the limitation by arranging for execv() to call reset_getopt() before executing the command.

Definition at line 89 of file getopt.h.

References nextchar, and optind.

Referenced by execv().

                                         {
        optind = 1;
        nextchar = 0;
}

---

Variable Documentation

char* optarg

Option argument.

This will point to the argument for the most recently returned option, if applicable.

Definition at line 38 of file getopt.c.

Referenced by imgfetch_core_exec(), match_long_option(), and match_short_option().

int optind

Current option index.

This is an index into the argv[] array. When getopt() returns -1, optind is the index to the first element that is not an option.

Definition at line 41 of file exec.c.

Referenced by dhcp_exec(), gdbstub_exec(), get_argv_argument(), getopt_long(), ifcommon_exec(), imgargs_exec(), imgexec_exec(), imgfetch_core_exec(), imgfree_exec(), imgload_exec(), imgstat_exec(), match_long_option(), match_short_option(), pxebs_exec(), reset_getopt(), route_exec(), and sanboot_exec().

int nextchar

Current option character index.

This is an index into the current element of argv[].

Definition at line 42 of file exec.c.

Referenced by getopt_long(), match_short_option(), and reset_getopt().

int optopt

Unrecognised option.

When an unrecognised option is encountered, the actual option character is stored in optopt.

Definition at line 61 of file getopt.c.

Referenced by getopt_long().