Go forward to strerror
Go backward to strcpy
Go up to Strings
Go to the top op libc

`strcspn'--count chars not in string

     size_t strcspn(const char *S1, const char *S2);
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).
`strcspn' returns the length of the substring found.
`strcspn' is ANSI C.
   `strcspn' requires no supporting OS subroutines.