/* The getopt() function parses the command line arguments. Its arguments argc and argv are the argument count and array as passed to the main() function on program invocation. An element of argv that starts with `/'is an option element. If getopt() is called repeatedly, it returns successively each of the option characters from each of the option elements. If there are no more option characters, getopt() returns -1. Then optind is the index in argv of the first argv element that is not an option. optstring is a string containing the legitimate option characters. If such a character is followed by a colon, the option requires an argument, so getopt places a pointer to the following text in the same argv-element, or the text of the following argv-element, in optarg. If getopt() does not recognize an option character, it prints an error message to stderr, stores the character in optopt, and returns `?'. The calling program MUST TURN ON THIS BEHAVIOR by setting opterr to 1. */ #ifndef _GETOPT_H #define _GETOPT_H #ifdef __cplusplus extern "C" { #endif extern char *optarg; /* Global argument pointer. */ extern int optind; /* Global argv index. */ extern int opterr; /* Global error message flag. */ int getopt(int argc, char *argv[], char *optstring); #ifdef __cplusplus } #endif #endif