strspn, strcspn — get length of a prefix substring

Synopsis

#include <string.h>

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

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

Description

The strspn() function calculates the length (in bytes) of the initial segment of s which consists entirely of bytes in accept.

The strcspn() function calculates the length of the initial segment of s which consists entirely of bytes not in reject.

Return Value

The strspn() function returns the number of bytes in the initial segment of s which consist only of bytes from accept.

The strcspn() function returns the number of bytes in the initial segment of s which are not in the string reject.

Attributes

For an explanation of the terms used in this section, see attributes(7).

Interface Attribute Value
strspn(), strcspn() Thread safety MT-Safe

Conforming to

POSIX.1-2001, POSIX.1-2008, C89, C99, SVr4, 4.3BSD.

See Also

index(3), memchr(3), rindex(3), strchr(3), string(3), strpbrk(3), strsep(3), strstr(3), strtok(3), wcscspn(3), wcsspn(3)

Colophon

This page is part of release 5.04 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

Referenced By

index(3), memchr(3), signal-safety(7), strchr(3), string(3), strnstr.3bsd(3), strpbrk(3), strsep(3), strstr(3), strtok(3), wcscspn(3), wcsspn(3).

The man page strcspn(3) is an alias of strspn(3).

2015-08-08 Linux Programmer's Manual