/* IBM_PROLOG_BEGIN_TAG                                                   */
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/* $Source: import/chips/p9/common/pmlib/ppc405lib/strcasecmp.c $         */
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/* [+] International Business Machines Corp.                              */
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/* IBM_PROLOG_END_TAG                                                     */

/// \file strcasecmp.c
/// \brief Implementation of strcasecmp() and strncasecmp()
///
/// These routines are rarely used, hence broken out into a separate file to
/// save code space for most applications.

#include "ssx.h"
#include "string.h"

/// Compare two strings ignoring case
///
/// The strcasecmp() function compares the two strings \a s1 and \a s2,
/// ignoring the case of the characters.  It returns an integer less than,
/// equal to, or greater than zero if \a s1 is found, respectively, to be less
/// than, to match, or be greater than \a s2.

int
strcasecmp(const char* s1, const char* s2)
{
    int rc;

    if (s1 == s2)
    {
        rc = 0;
    }
    else
    {
        while(*s1 && (tolower(*s1) == tolower(*s2)))
        {
            s1++;
            s2++;
        }

        rc = *((unsigned char*)s1) - *((unsigned char*)s2);
    }

    return rc;
}


/// Compare a portion of two strings ignoring case
///
/// The strncmp() function compares at most the first \n characters of the two
/// strings \a s1 and \a s2, ignoring the case of the characters.  It returns
/// an integer less than, equal to, or greater than zero if (the prefix of) \a
/// s1 is found, respectively, to be less than, to match, or be greater than
/// (the prefix of) \a s2.

int
strncasecmp(const char* s1, const char* s2, size_t n)
{
    int rc;

    if ((s1 == s2) || (n == 0))
    {
        rc = 0;
    }
    else
    {
        while(*s1 && (tolower(*s1) == tolower(*s2)) && n--)
        {
            s1++;
            s2++;
        }

        rc = *((unsigned char*)s1) - *((unsigned char*)s2);
    }

    return rc;
}
