Hey,
regarding atoi:
#include <stdio.h>
int main(){
printf("value: %d\n",atoi("nosegv123"));
return(0);
}
output:
value: 0
this doesn't segfault
SYNOPSIS
#include <ctype.h>
int isalnum(int c);
int isalpha(int c);
int isascii(int c);
int isblank(int c);
int iscntrl(int c);
int isdigit(int c);
int isgraph(int c);
int islower(int c);
int isprint(int c);
int ispunct(int c);
int isspace(int c);
int isupper(int c);
int isxdigit(int c);
ctype only takes one variable as argument _not_ a string, he would
have to check every element of the array with isdigit.
Markus
On Fri, 4 Mar 2005 22:16:54 +0100 (CET), J. <[EMAIL PROTECTED]> wrote:
> 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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