check the given string is numeric or not.

knowledge_gain · #1 (**permalink**) 06-18-2007

Hi,

how to check the given string is numeric or not , without converting ( using strtol...).

for ex: if string is C01 - non-numeric data
if string is 001 - numeric data

TIA

ilko_partizan · #2 (**permalink**) 06-18-2007

You are trying with following standard C library function:

This function test only for decimal-digit character
http://www.freebsd.org/cgi/man.cgi?q...SD+6.2-RELEASE

This function test for hexadecimal-digit character
http://www.freebsd.org/cgi/man.cgi?q...SE&format=html

Best regards,
Iliyan Varshilov

knowledge_gain · #3 (**permalink**) 06-18-2007

i don't want to check in a loop using isdigit. need something simple.

ilko_partizan · #4 (**permalink**) 06-18-2007

You are trying to solve your validation problem with regular expression library function .
http://www.opengroup.org/onlinepubs/...s/regcomp.html

Best regards,
Iliyan Varshilov

porter · #5 (**permalink**) 06-18-2007

Quote:

Originally Posted by knowledge_gain

i don't want to check in a loop using isdigit. need something simple.

You are posting is a C programming forum and loops are too difficult?

Octal · #6 (**permalink**) 06-18-2007

Quote:

Originally Posted by knowledge_gain

i don't want to check in a loop using isdigit. need something simple.

You could make your own function:

Code:

#include <stdlib.h>

short strchk (char *s) {
	unsigned short r = 0;

	while (*++s) {
		if (isdigit(s)) {
			r = 1;
		} else {
			r = 0;
			break;
		}
	}
	return r;
}

Note that I didn't compile this code, but it should work.

porter · #7 (**permalink**) 06-18-2007

That routine does not check the first character of the string...

Try

Code:

int is_numeric(const char *p) {
     if (*p) {
          char c;
          while ((c=*p++)) {
                if (!isdigit(c)) return 0;
          }
          return 1;
      }
      return 0;
}

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