NAME

strspn, strcspn —

span a string

LIBRARY

Standard C Library (libc, -lc)

SYNOPSIS

#include <string.h>

size_t
strspn(const char *s, const char *charset);

size_t
strcspn(const char *s, const char *charset);

DESCRIPTION

The strspn() function spans the initial part of the null-terminated string s as long as the characters from s occur in the null-terminated string charset. In other words, it computes the string array index of the first character of s which is not in charset, else the index of the first null character.

The strcspn() function spans the initial part of the null-terminated string s as long as the characters from s do not occur in the null-terminated string charset (it spans the complement of charset). In other words, it computes the string array index of the first character of s which is also in charset, else the index of the first null character.

RETURN VALUES

The strspn() and strcspn() functions return the number of characters spanned.

STANDARDS

The strspn() and strcspn() functions conform to ISO/IEC 9899:1990 (“ISO C90”).