strlen(3) — Linux manual page

strlen(3)               Library Functions Manual               strlen(3)

NAME

       strlen - calculate the length of a string

LIBRARY

       Standard C library (libc, -lc)

SYNOPSIS

       #include <string.h>

       size_t strlen(const char *s);

DESCRIPTION

       The strlen() function calculates the length of the string pointed
       to by s, excluding the terminating null byte ('\0').

RETURN VALUE

       The strlen() function returns the number of bytes in the string
       pointed to by s.

ATTRIBUTES

       For an explanation of the terms used in this section, see
       attributes(7).
       ┌─────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                           │ Attribute     │ Value   │
       ├─────────────────────────────────────┼───────────────┼─────────┤
       │ strlen()                            │ Thread safety │ MT-Safe │
       └─────────────────────────────────────┴───────────────┴─────────┘

STANDARDS

       C11, POSIX.1-2008.

HISTORY

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

NOTES

       In cases where the input buffer may not contain a terminating
       null byte, strnlen(3) should be used instead.

SEE ALSO

       string(3), strnlen(3), wcslen(3), wcsnlen(3)

COLOPHON

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Linux man-pages 6.9.1          2024-06-15                      strlen(3)

Pages that refer to this page: lber-types(3), memchr(3), pmfstring(3), regex(3), strchr(3), string(3), strnlen(3), wcslen(3), signal-safety(7)

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