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ComputingCString.h

strspn

Span a string

Interface

#include <string.h>
size_t strspn (const char *s, const char *charset)

Description

The strspn function spans the initial part of the null-terminated string \c s as long as the characters from \c s occur in string \c charset.

Example:
Example - Span a string
Workings
#include <stdio.h>
#include <string.h>
int main()
{
  char s[20] = "0123456abcde", t[11] = "0123456789";
  printf("The position of the first non-digit in s is: %d.\n", strspn(s, t));
  return 0;
}
Solution
Output:
The position of the first non-digit in s is: 7.

Return Values

The strspn function returns the number of characters spanned.

Standards

The strspn function conforms to ISO/IEC 9899:1990 ("ISO C90").