Files
apg/getopt.c
Adel I. Mirzazhanov 900ff5ea18 APG v2.1.0
2023-07-12 15:36:18 +06:00

95 lines
2.1 KiB
C

/*
* Modified by Adel I. Mirzazhanov 2002
* getopt - get option letter from argv
*
* This is a version of the public domain getopt() implementation by
* Henry Spencer, changed for 4.3BSD compatibility (in addition to System V).
* It allows rescanning of an option list by setting optind to 0 before
* calling, which is why we use it even if the system has its own (in fact,
* this one has a unique name so as not to conflict with the system's).
* Thanks to Dennis Ferguson for the appropriate modifications.
*
* This file is in the Public Domain.
*/
#include <stdio.h>
#include "getopt.h"
static int badopt(const char *mess,int ch);
char *apg_optarg; /* Global argument pointer. */
int apg_optind = 0; /* Global argv index. */
int apg_opterr = 1; /* for compatibility, should error be printed? */
int apg_optopt; /* for compatibility, option character checked */
static char *scan = NULL; /* Private scan pointer. */
static const char *prog = "apg";
/*
* Print message about a bad option.
*/
static int
badopt(const char *mess,int ch)
{
if (apg_opterr) {
fprintf(stderr,"%s%s%c\n", prog, mess, ch);
fflush(stderr);
}
return ('?');
}
int
apg_getopt(int argc,char *argv[],const char *optstring)
{
register char c;
register const char *place;
prog = argv[0];
apg_optarg = NULL;
if (apg_optind == 0) {
scan = NULL;
apg_optind++;
}
if (scan == NULL || *scan == '\0') {
if (apg_optind >= argc
|| argv[apg_optind][0] != '-'
|| argv[apg_optind][1] == '\0') {
return (EOF);
}
if (argv[apg_optind][1] == '-'
&& argv[apg_optind][2] == '\0') {
apg_optind++;
return (EOF);
}
scan = argv[apg_optind++]+1;
}
c = *scan++;
apg_optopt = c & 0377;
for (place = optstring; place != NULL && *place != '\0'; ++place)
if (*place == c)
break;
if (place == NULL || *place == '\0' || c == ':' || c == '?') {
return (badopt(": unknown option -", c));
}
place++;
if (*place == ':') {
if (*scan != '\0') {
apg_optarg = scan;
scan = NULL;
} else if (apg_optind >= argc) {
return (badopt(": option requires an argument -", c));
} else {
apg_optarg = argv[apg_optind++];
}
}
return (c & 0377);
}