strlen(3) - Man pages

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)

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

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