posix man page for strlen

STRLEN(3P)						     POSIX Programmer's Manual							STRLEN(3P)

PROLOG
       This  manual page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (consult the correspond-
       ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

NAME
       strlen, strnlen -- get length of fixed size string

SYNOPSIS
       #include <string.h>

       size_t strlen(const char *s);
       size_t strnlen(const char *s, size_t maxlen);

DESCRIPTION
       For strlen(): The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the  requirements
       described here and the ISO C standard is unintentional. This volume of POSIX.1-2008 defers to the ISO C standard.

       The strlen() function shall compute the number of bytes in the string to which s points, not including the terminating NUL character.

       The  strnlen()  function shall compute the smaller of the number of bytes in the array to which s points, not including the terminating NUL
       character, or the value of the maxlen argument. The strnlen() function shall never examine more than maxlen bytes of the array  pointed	to
       by s.

RETURN VALUE
       The strlen() function shall return the length of s; no return value shall be reserved to indicate an error.

       The strnlen() function shall return an integer containing the smaller of either the length of the string pointed to by s or maxlen.

ERRORS
       No errors are defined.

       The following sections are informative.

EXAMPLES
   Getting String Lengths
       The following example sets the maximum length of key and data by using strlen() to get the lengths of those strings.

	   #include <string.h>
	   ...
	   struct element {
	       char *key;
	       char *data;
	   };
	   ...
	   char *key, *data;
	   int len;

	   *keylength = *datalength = 0;
	   ...
	   if ((len = strlen(key)) > *keylength)
	       *keylength = len;
	   if ((len = strlen(data)) > *datalength)
	       *datalength = len;
	   ...

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       wcslen()

       The Base Definitions volume of POSIX.1-2008, <string.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition, Standard for Information Technol-
       ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, Copyright (C)  2013  by	the  Institute	of
       Electrical and Electronics Engineers, Inc and The Open Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
       event of any discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Stan-
       dard is the referee document. The original Standard can be obtained online at http://www.unix.org/online.html .

       Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE
/The Open Group						       2013								STRLEN(3P)