newlib-cygwin/newlib/libc/string/strcspn.c

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2000-02-18 03:39:52 +08:00
/*
FUNCTION
<<strcspn>>---count chars 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;
}