On Thu, 3 Mar 2005, Fabio wrote:
> Hello,
>
> I am coding a small utility for system administrator.
> The following command line options will be accepted:
........
> This was I got on a getopt() man page, I understand some basic concept,
> but I cant put the unaccpted arguments to work. Thanks alot if someone
> can build this from scratch.
>
> Thanks in advance,
>
> fabio.
Friday, March 03
You could use an regex to determine if your dealing with an INT or
not.. Or check the option string with isdigit() <ctype.h>.
If atoi is used on non-digit conversion the result is a segfault.
Use strtol family instead because atoi can't detect errors. Also
casting return value's is a bad idea since they can hide errors..
your code with might looklike something like this....
#include <stdio.h>
#include <getopt.h>
#include <stdlib.h>
#include <regex.h>
#include <locale.h>
#define PACKAGE "getoptex"
#define VERSION "0.0.1"
void print_help(int exval);
int isthisanint(char *str);
int main(int argc, char *argv[]) {
int opt;
/*
// no arguments given
*/
if(argc == 1) {
fprintf(stderr, "This program needs arguments....\n\n");
print_help(1);
}
while((opt = getopt(argc, argv, "hVvd:f:o:")) != -1) {
switch(opt) {
case 'h':
print_help(0);
case 'V':
printf("%s %s\n\n", PACKAGE, VERSION);
exit(0);
case 'v':
printf("%s: Verbose option is set `%c'\n", PACKAGE, optopt);
break;
case 'd':
printf("%s: isthisanint(%s), says: %d\n", PACKAGE,
optarg, isthisanint(optarg));
break;
case 'f':
printf("%s: Filename %s\n", PACKAGE, optarg);
break;
case 'o':
printf("Output: %s\n", optarg);
break;
case ':':
fprintf(stderr, "%s: Error - Option `%c' needs a value\n\n", PACKAGE,
optopt);
exit(1);
case '?':
fprintf(stderr, "%s: Error - No such option: `%c'\n\n", PACKAGE, optopt);
exit(1);
}
}
/*
// print all remaining options
*/
for(; optind < argc; optind++)
printf("argument: %s\n", argv[optind]);
return 0;
}
void print_help(int exval) {
printf("%s,%s show working getopt example\n", PACKAGE, VERSION);
printf("%s [-h] [-V] [-v] [-d INT] [-f FILE] [-o FILE]\n\n", PACKAGE);
printf(" -h print this help and exit\n");
printf(" -V print version and exit\n\n");
printf(" -v set verbose flag\n");
printf(" -d INT set `-d' to `INT'\n");
printf(" -f FILE set intput file\n");
printf(" -o FILE set output file\n\n");
exit(exval);
}
int isthisanint(char *str) {
regex_t re;
int retval = -1;
setlocale(LC_ALL, "");
if(regcomp(&re, "^([0-9]*)$", REG_EXTENDED) != 0) {
fprintf(stderr, "%s: Error - Unable to compile regex", PACKAGE);
return -1;
}
if(regexec(&re, str, 0, NULL, 0) != 0)
retval = -1;
else
retval = atoi(str);
/* or.. Like listed in the manual page */
/* strtol(nptr, (char **)NULL, 10); */
regfree(&re);
return retval;
}
Hope that left you with some usable idea's...
GoodLuck..
J.
--
http://www.rdrs.net/
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