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_OR_UBDL)
int	getopt_long (int argc, char *const argv[], const char *optstring, const struct option *longopts, int *longindex)
	Parse command-line options. More...
static int	getopt (int argc, char *const argv[], const char *optstring)
	Parse command-line options. More...
static void	reset_getopt (void)
	Reset getopt() internal state. More...

Variables
char *	optarg
	Option argument. More...
int	optind
	Current option index. More...
int	nextchar
	Current option character index. More...
int	optopt
	Unrecognised option. More...

Detailed Description

Parse command-line options.

Definition in file getopt.h.

Enumeration Type Documentation

getopt_argument_requirement

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()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

getopt_long()

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 229 of file getopt.c.

                                                                  {
        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++) == '-' ) {
                /* "--" indicates end of options */
                if ( *opttext == '\0' ) {
                        optind++;
                        return -1;
                }
                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 '?';
}

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

Referenced by getopt(), linux_args_parse(), and reparse_options().

getopt()

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

inlinestatic

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.

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

References getopt_long(), and NULL.

reset_getopt()

static void reset_getopt ( void  )

inlinestatic

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.

                                         {
        optind = 1;
        nextchar = 0;
}

References nextchar, and optind.

Referenced by execv(), and linux_args_parse().

Variable Documentation

optarg

char* optarg

Option argument.

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

Definition at line 43 of file getopt.c.

Referenced by linux_args_parse(), match_long_option(), match_short_option(), and reparse_options().

optind

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 51 of file getopt.c.

Referenced by cert_exec(), choose_exec(), colour_exec(), config_exec(), cpair_exec(), cpuid_exec(), digest_exec(), dynui_exec(), echo_exec(), exit_exec(), fcels_exec(), gdbstub_exec(), get_argv_argument(), getopt_long(), goto_exec(), ifcommon_exec(), imgdecrypt_exec(), imgextract_exec(), imgmem_exec(), imgmulti_exec(), imgsingle_exec(), imgverify_exec(), inc_exec(), iseq_exec(), isset_exec(), item_exec(), lotest_exec(), match_long_option(), match_short_option(), nslookup_exec(), ntp_exec(), param_exec(), pciscan_exec(), ping_exec(), prompt_exec(), pxebs_exec(), reparse_options(), reset_getopt(), sanboot_core_exec(), set_core_exec(), shim_exec(), show_exec(), sleep_exec(), usbscan_exec(), vcreate_exec(), and vdestroy_exec().

nextchar

int nextchar

Current option character index.

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

Definition at line 58 of file getopt.c.

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

optopt

int optopt

Unrecognised option.

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

Definition at line 66 of file getopt.c.

Referenced by getopt_long().