STRSPN(3) Linux Programmer's Manual STRSPN(3) NAME 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) 2021-03-22 STRSPN(3)