PROLOG | NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ERRORS | EXAMPLES | APPLICATION USAGE | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT

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

PROLOG         top

       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         top

       strcoll, strcoll_l — string comparison using collating information

SYNOPSIS         top

       #include <string.h>

       int strcoll(const char *s1, const char *s2);
       int strcoll_l(const char *s1, const char *s2,
           locale_t locale);

DESCRIPTION         top

       For strcoll(): 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 strcoll() and strcoll_l() functions shall compare the string
       pointed to by s1 to the string pointed to by s2, both interpreted as
       appropriate to the LC_COLLATE category of the current locale, or of
       the locale represented by locale, respectively.

       The strcoll() and strcoll_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 strcoll(), or strcoll_l() then check errno.

       The behavior is undefined if the locale argument to strcoll_l() is
       the special locale object LC_GLOBAL_LOCALE or is not a valid locale
       object handle.

RETURN VALUE         top

       Upon successful completion, strcoll() shall return an integer greater
       than, equal to, or less than 0, according to whether the string
       pointed to by s1 is greater than, equal to, or less than the string
       pointed to by s2 when both are interpreted as appropriate to the
       current locale.  On error, strcoll() may set errno, but no return
       value is reserved to indicate an error.

       Upon successful completion, strcoll_l() shall return an integer
       greater than, equal to, or less than 0, according to whether the
       string pointed to by s1 is greater than, equal to, or less than the
       string pointed to by s2 when both are interpreted as appropriate to
       the locale represented by locale.  On error, strcoll_l() may set
       errno, but no return value is reserved to indicate an error.

ERRORS         top

       These functions may fail if:

       EINVAL The s1 or s2 arguments contain characters outside the domain
              of the collating sequence.

       The following sections are informative.

EXAMPLES         top

   Comparing Nodes
       The following example uses an application-defined function,
       node_compare(), to compare two nodes based on an alphabetical
       ordering of the string field.

           #include <string.h>
           ...
           struct node { /* These are stored in the table. */
               char *string;
               int length;
           };
           ...
           int node_compare(const void *node1, const void *node2)
           {
               return strcoll(((const struct node *)node1)->string,
                   ((const struct node *)node2)->string);
           }
           ...

APPLICATION USAGE         top

       The strxfrm() and strcmp() functions should be used for sorting large
       lists.

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       alphasort(3p), strcmp(3p), strxfrm(3p)

       The Base Definitions volume of POSIX.1‐2008, string.h(0p)

COPYRIGHT         top

       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 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 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.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                 2013                         STRCOLL(3P)

Pages that refer to this page: string.h(0p)alphasort(3p)localeconv(3p)setlocale(3p)strxfrm(3p)