/* FUNCTION <<strcspn>>---count characters not in string INDEX strcspn ANSI_SYNOPSIS size_t strcspn(const char *<[s1]>, const char *<[s2]>); TRAD_SYNOPSIS size_t strcspn(<[s1]>, <[s2]>) char *<[s1]>; char *<[s2]>; DESCRIPTION This function computes the length of the initial part of the string pointed to by <[s1]> which consists entirely of characters <[NOT]> from the string pointed to by <[s2]> (excluding the terminating null character). RETURNS <<strcspn>> returns the length of the substring found. PORTABILITY <<strcspn>> is ANSI C. <<strcspn>> requires no supporting OS subroutines. */ #include <string.h> size_t _DEFUN (strcspn, (s1, s2), _CONST char *s1 _AND _CONST char *s2) { _CONST char *s = s1; _CONST char *c; while (*s1) { for (c = s2; *c; c++) { if (*s1 == *c) break; } if (*c) break; s1++; } return s1 - s; }