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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  corresponding
       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 char-
       acter, 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 Technology
       --  Portable  Operating  System  Interface (POSIX), The Open Group Base
       Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri-
       cal  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  Standard
       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.ker-
       nel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group                  2013                           STRLEN(3P)