strcasecmp(3p) — Linux manual page

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

       strcasecmp, strcasecmp_l, strncasecmp, strncasecmp_l — case-
       insensitive string comparisons

SYNOPSIS

       #include <strings.h>

       int strcasecmp(const char *s1, const char *s2);
       int strcasecmp_l(const char *s1, const char *s2,
           locale_t locale);
       int strncasecmp(const char *s1, const char *s2, size_t n);
       int strncasecmp_l(const char *s1, const char *s2,
           size_t n, locale_t locale);

DESCRIPTION

       The strcasecmp() and strcasecmp_l() functions shall compare,
       while ignoring differences in case, the string pointed to by s1
       to the string pointed to by s2.  The strncasecmp() and
       strncasecmp_l() functions shall compare, while ignoring
       differences in case, not more than n bytes from the string
       pointed to by s1 to the string pointed to by s2.

       The strcasecmp() and strncasecmp() functions use the current
       locale to determine the case of the characters.

       The strcasecmp_l() and strncasecmp_l() functions use the locale
       represented by locale to determine the case of the characters.

       When the LC_CTYPE category of the locale being used is from the
       POSIX locale, these functions shall behave as if the strings had
       been converted to lowercase and then a byte comparison performed.
       Otherwise, the results are unspecified.

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

RETURN VALUE

       Upon completion, strcasecmp() and strcasecmp_l() shall return an
       integer greater than, equal to, or less than 0, if the string
       pointed to by s1 is, ignoring case, greater than, equal to, or
       less than the string pointed to by s2, respectively.

       Upon successful completion, strncasecmp() and strncasecmp_l()
       shall return an integer greater than, equal to, or less than 0,
       if the possibly null-terminated array pointed to by s1 is,
       ignoring case, greater than, equal to, or less than the possibly
       null-terminated array pointed to by s2, respectively.

ERRORS

       No errors are defined.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       None.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       wcscasecmp(3p)

       The Base Definitions volume of POSIX.1‐2017, strings.h(0p)

COPYRIGHT

       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 at http://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, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group               2017                    STRCASECMP(3P)

Pages that refer to this page: strings.h(0p), strncasecmp(3p), wcscasecmp(3p)

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