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strcoll(3p) — Linux manual page

STRCOLL(3P)             POSIX Programmer's ManualSTRCOLL(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_tlocale);

DESCRIPTION        top

       Forstrcoll(): 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.1‐2017 defers to the ISO C       standard.       Thestrcoll() andstrcoll_l() functions shall compare the string       pointed to bys1 to the string pointed to bys2, both interpreted       as appropriate to theLC_COLLATE category of the current locale,       or of the locale represented bylocale, respectively.       Thestrcoll() andstrcoll_l() functions shall not change the       setting oferrno if successful.       Since no return value is reserved to indicate an error, an       application wishing to check for error situations should seterrno       to 0, then callstrcoll(), orstrcoll_l() then checkerrno.       The behavior is undefined if thelocale argument tostrcoll_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 bys1 is greater than, equal to, or less than       the string pointed to bys2 when both are interpreted as       appropriate to the current locale.  On error,strcoll() may seterrno, 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 bys1 is greater than, equal to, or less than       the string pointed to bys2 when both are interpreted as       appropriate to the locale represented bylocale.  On error,strcoll_l() may seterrno, but no return value is reserved to       indicate an error.

ERRORS        top

       These functions may fail if:EINVALThes1 ors2 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 thestring 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

       Thestrxfrm() andstrcmp() 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.1‐2017,string.h(0p)

COPYRIGHT        top

       Portions of this text are reprinted and reproduced in electronic       form from IEEE Std 1003.1-2017, Standard for Information       Technology -- Portable Operating System Interface (POSIX), The       Open Group Base Specifications Issue 7, 2018 Edition, Copyright       (C) 2018 by the Institute of Electrical and Electronics Engineers,       Inc and The Open Group.  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 athttp://www.opengroup.org/unix/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, seehttps://www.kernel.org/doc/man-pages/reporting_bugs.html .IEEE/The Open Group                2017STRCOLL(3P)

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

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