getopt

Name

getopt -- parse command line options

Synopsis

int getopt(int argc, char * const argv[], const char *optstring);
extern char *optarg;
extern int optind, opterr, optopt;

GNU supports the following extensions of getopt:

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

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

Description

The getopt() function parses command line arguments. GNU and POSIX specifications for this function vary in the following areas.

Option Characteristics

GNU specifies that:

POSIX specifies that:

Extensions

GNU specifies that:

POSIX specifies that:

Return Values

GNU specifies the following getopt() return values:

GNU specifies the following getopt_long() and getopt_long_only() return values:

POSIX specifies the following getopt() return values:

Environmental Variables

GNU specifies that:

Environmental Variables

POSIX.2 Interpretation 150 reports a technical error in the function of getopt(). GNU implements the correct behavior of getopt().