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STRXFRM(3P)                POSIX Programmer's Manual               STRXFRM(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
       strxfrm, strxfrm_l -- string transformation
SYNOPSIS
       #include <string.h>
       size_t strxfrm(char *restrict s1, const char *restrict s2, size_t n);
       size_t strxfrm_l(char *restrict s1, const char *restrict s2,
           size_t n, locale_t locale);
DESCRIPTION
       For strxfrm(): 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  strxfrm()  and  strxfrm_l()  functions  shall transform the string
       pointed to by s2 and place the resulting string into the array  pointed
       to  by  s1.   The transformation is such that if strcmp() is applied to
       two transformed strings, it shall return a value  greater  than,  equal
       to,  or  less  than 0, corresponding to the result of strcoll() or str-
       coll_l(), respectively, applied to the same two original  strings  with
       the  same  locale.   No more than n bytes are placed into the resulting
       array pointed to by s1, including the terminating NUL character.  If  n
       is  0,  s1  is  permitted  to be a null pointer. If copying takes place
       between objects that overlap, the behavior is undefined.
       The strxfrm() and strxfrm_l() functions shall not change the setting of
       errno if successful.
       Since  no return value is reserved to indicate an error, an application
       wishing to check for error situations should set errno to 0, then  call
       strxfrm() or strxfrm_l(), then check errno.
       The  behavior is undefined if the locale argument to strxfrm_l() is the
       special locale object LC_GLOBAL_LOCALE or is not a valid locale  object
       handle.
RETURN VALUE
       Upon  successful completion, strxfrm() and strxfrm_l() shall return the
       length of the transformed string (not  including  the  terminating  NUL
       character).  If  the  value  returned is n or more, the contents of the
       array pointed to by s1 are unspecified.
       On error, strxfrm() and strxfrm_l() may set errno but no  return  value
       is reserved to indicate an error.
ERRORS
       These functions may fail if:
       EINVAL The  string  pointed  to  by the s2 argument contains characters
              outside the domain of the collating sequence.
       The following sections are informative.
EXAMPLES
       None.
APPLICATION USAGE
       The transformation function is such that two transformed strings can be
       ordered by strcmp() as appropriate to collating sequence information in
       the current locale (category LC_COLLATE).
       The fact that when n is 0 s1 is permitted to be a null pointer is  use-
       ful to determine the size of the s1 array prior to making the transfor-
       mation.
RATIONALE
       None.
FUTURE DIRECTIONS
       None.
SEE ALSO
       strcmp(), strcoll()
       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                          STRXFRM(3P)