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

54 lines
830 B
C

/*
FUNCTION
<<strspn>>---find initial match
INDEX
strspn
SYNOPSIS
#include <string.h>
size_t strspn(const char *<[s1]>, const char *<[s2]>);
DESCRIPTION
This function computes the length of the initial segment of
the string pointed to by <[s1]> which consists entirely of
characters from the string pointed to by <[s2]> (excluding the
terminating null character).
RETURNS
<<strspn>> returns the length of the segment found.
PORTABILITY
<<strspn>> is ANSI C.
<<strspn>> requires no supporting OS subroutines.
QUICKREF
strspn ansi pure
*/
#include <string.h>
size_t
strspn (const char *s1,
const char *s2)
{
const char *s = s1;
const char *c;
while (*s1)
{
for (c = s2; *c; c++)
{
if (*s1 == *c)
goto found;
}
if (*c == '\0')
break;
found:
s1++;
}
return s1 - s;
}