Pass arguments into C program from command line
You could use getopt.
#include <ctype.h> #include <stdio.h> #include <stdlib.h> #include <unistd.h> int main (int argc, char **argv) { int bflag = 0; int sflag = 0; int index; int c; opterr = 0; while ((c = getopt (argc, argv, "bs")) != -1) switch (c) { case 'b': bflag = 1; break; case 's': sflag = 1; break; case '?': if (isprint (optopt)) fprintf (stderr, "Unknown option `-%c'.\n", optopt); else fprintf (stderr, "Unknown option character `\\x%x'.\n", optopt); return 1; default: abort (); } printf ("bflag = %d, sflag = %d\n", bflag, sflag); for (index = optind; index < argc; index++) printf ("Non-option argument %s\n", argv[index]); return 0; }
In C, this is done using arguments passed to your main() function:
int main(int argc, char *argv[]){ int i = 0; for (i = 0; i < argc; i++) { printf("argv[%d] = %s\n", i, argv[i]); } return 0;}More information can be found online such as this Arguments to main article.
Consider using getopt_long(). It allows both short and long options in any combination.
#include <stdio.h>#include <stdlib.h>#include <getopt.h>/* Flag set by `--verbose'. */static int verbose_flag;intmain (int argc, char *argv[]){ while (1) { static struct option long_options[] = { /* This option set a flag. */ {"verbose", no_argument, &verbose_flag, 1}, /* These options don't set a flag. We distinguish them by their indices. */ {"blip", no_argument, 0, 'b'}, {"slip", no_argument, 0, 's'}, {0, 0, 0, 0} }; /* getopt_long stores the option index here. */ int option_index = 0; int c = getopt_long (argc, argv, "bs", long_options, &option_index); /* Detect the end of the options. */ if (c == -1) break; switch (c) { case 0: /* If this option set a flag, do nothing else now. */ if (long_options[option_index].flag != 0) break; printf ("option %s", long_options[option_index].name); if (optarg) printf (" with arg %s", optarg); printf ("\n"); break; case 'b': puts ("option -b\n"); break; case 's': puts ("option -s\n"); break; case '?': /* getopt_long already printed an error message. */ break; default: abort (); } } if (verbose_flag) puts ("verbose flag is set"); /* Print any remaining command line arguments (not options). */ if (optind < argc) { printf ("non-option ARGV-elements: "); while (optind < argc) printf ("%s ", argv[optind++]); putchar ('\n'); } return 0;}Related: