C + + Parse command-line arguments

Related library functions # include <unistd.h> #include <getopt.h>int getopt (int argc, char * const ARGV[],CONST char *optstring); extern char *optarg;extern int optind, Opterr, optopt;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,co NST struct option *longopts, int *longindex);

EG1:

#include  <stdio.h> #include  <getopt.h>int main (int argc,char *argv[])  {    int opt;    char *optstring =  "A:b:c:de The; //  represents the-A,-B,-C,-D,-E command line parameter, with the expression parameter with: can specify a value, so the de cannot specify a value of     while (opt =  Getopt (argc,argv,optstring))  != -1) {        printf ("opt  = %c\n ", opt);         printf (" optarg = %s\n ", OPTARG);         printf ("optind = %d\n", Optind);         printf ("argv[optind-1] = %s\n\n", Argv[optind-1]);     }    return 0;} #./test_arg -a 1 -b 2 -c 3 -d -eopt = aoptarg =  1optind = 3argv[optind-1] = 1opt = boptarg = 2optind = 5argv[optind-1] = 2opt = coptarg = 3optind = 7argv[ optind-1] = 3opt = doptarg =  (NULL) optind = 8argv[optind-1] =  -dopt = eoptarg =  (NULL) OPTIND&NBSP;=&NBSP;9ARGV[OPTIND-1]&NBSP;=&NBSP;-E

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C + + Parse command-line arguments