ref: 93c94e8c4070d8018a79014e8f5f07d00115462c
dir: /sys/src/libc/port/strchr.c/
#include <u.h>
#include <libc.h>
char*
strchr(char *s, int c)
{
char r;
if(c == 0)
while(*s++)
;
else
while((r = *s++) != c)
if(r == 0)
return 0;
return s-1;
}