windows-nt/Source/XPSP1/NT/base/crts/crtw32/string/strlwr.c

/***
*strlwr.c - routine to map upper-case characters in a string to lower-case
*
*       Copyright (c) 1985-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
*       Converts all the upper case characters in a string to lower case,
*       in place.
*
*Revision History:
*       05-31-89  JCR   C version created.
*       02-27-90  GJF   Fixed calling type, #include <cruntime.h>, fixed
*                       copyright.
*       10-02-90  GJF   New-style function declarator.
*       01-18-91  GJF   ANSI naming.
*       09-18-91  ETC   Locale support under _INTL switch.
*       12-08-91  ETC   Updated nlsapi; added multithread.
*       08-19-92  KRS   Activated NLS support.
*       08-22-92  SRW   Allow INTL definition to be conditional for building
*                       ntcrt.lib
*       09-02-92  SRW   Get _INTL definition via ..\crt32.def
*       04-06-93  SKS   Replace _CRTAPI* with __cdecl
*       06-01-93  CFW   Simplify "C" locale test.
*       06-02-93  SRW   ignore _INTL if _NTSUBSET_ defined.
*       09-15-93  CFW   Use ANSI conformant "__" names.
*       09-16-93  GJF   Merged NT SDK and Cuda versions.
*       09-22-93  CFW   Use __crtxxx internal NLS API wrapper.
*       11-09-93  CFW   Add code page for __crtxxx().
*       09-06-94  CFW   Remove _INTL switch.
*       10-24-94  GJF   Sped up C locale, multi-thread case.
*       12-29-94  CFW   Merge non-Win32.
*       01-10-95  CFW   Debug CRT allocs.
*       09-26-95  GJF   New locking macro, and scheme, for functions which
*                       reference the locale.
*       03-17-97  RDK   Added error flag to __crtLCMapStringA.
*       08-11-98  GJF   Revised multithread support based on threadlocinfo
*                       struct. Also, use _alloca instead of _malloc_crt.
*       05-17-99  PML   Remove all Macintosh support.
*       12-10-99  GB    Added support for recovery from stack overflow around
*                       _alloca().
*       05-01-00  BWT   Fix Posix.
*       03-13-01  PML   Fix memory leak if _alloca failed (vs7#224860)
*
*******************************************************************************/

#include <cruntime.h>
#include <string.h>
#include <malloc.h>
#include <locale.h>
#include <setlocal.h>
#include <limits.h>     /* for INT_MAX */
#include <mtdll.h>
#include <awint.h>
#include <dbgint.h>

/***
*char *_strlwr(string) - map upper-case characters in a string to lower-case
*
*Purpose:
*       _strlwr() converts upper-case characters in a null-terminated string
*       to their lower-case equivalents.  Conversion is done in place and
*       characters other than upper-case letters are not modified.
*
*       In the C locale, this function modifies only 7-bit ASCII characters
*       in the range 0x41 through 0x5A ('A' through 'Z').
*
*       If the locale is not the 'C' locale, LCMapString() is used to do
*       the work.  Assumes enough space in the string to hold result.
*
*Entry:
*       char *string - string to change to lower case
*
*Exit:
*       input string address
*
*Exceptions:
*       The original string is returned unchanged on any error.
*
*******************************************************************************/

char * __cdecl _strlwr (
        char * string
        )
{
#if     !defined(_NTSUBSET_) && !defined(_POSIX_)

        int dstlen;                 /* len of dst string, with null  */
        unsigned char *dst;         /* destination string */
        int malloc_flag = 0;
#ifdef  _MT
        pthreadlocinfo ptloci = _getptd()->ptlocinfo;

        if ( ptloci != __ptlocinfo )
            ptloci = __updatetlocinfo();

        if ( ptloci->lc_handle[LC_CTYPE] == _CLOCALEHANDLE )
#else
        if ( __lc_handle[LC_CTYPE] == _CLOCALEHANDLE )
#endif
        {
            char *cp;       /* traverses string for C locale conversion */

            for ( cp = string ; *cp ; ++cp )
                if ( ('A' <= *cp) && (*cp <= 'Z') )
                    *cp -= 'A' - 'a';

            return(string);
        }   /* C locale */

        /* Inquire size of dst string */
#ifdef  _MT
        if ( 0 == (dstlen = __crtLCMapStringA( ptloci->lc_handle[LC_CTYPE],
#else
        if ( 0 == (dstlen = __crtLCMapStringA( __lc_handle[LC_CTYPE],
#endif
                                               LCMAP_LOWERCASE,
                                               string,
                                               -1,
                                               NULL,
                                               0,
#ifdef  _MT
                                               ptloci->lc_codepage,
#else
                                               __lc_codepage,
#endif
                                               TRUE )) )
            return(string);

        /* Allocate space for dst */
        __try {
            dst = (unsigned char *)_alloca(dstlen * sizeof(unsigned char));
        }
        __except( EXCEPTION_EXECUTE_HANDLER )
        {
            _resetstkoflw();
            dst = NULL;
        }

        if ( dst == NULL ) {
            dst = (unsigned char *)_malloc_crt(dstlen * sizeof(unsigned char));
            malloc_flag++;
        }

        /* Map src string to dst string in alternate case */
        if ( (dst != NULL) &&
#ifdef  _MT
             (__crtLCMapStringA( ptloci->lc_handle[LC_CTYPE],
#else
             (__crtLCMapStringA( __lc_handle[LC_CTYPE],
#endif
                                 LCMAP_LOWERCASE,
                                 string,
                                 -1,
                                 dst,
                                 dstlen,
#ifdef  _MT
                                 ptloci->lc_codepage,
#else
                                 __lc_codepage,
#endif
                                 TRUE ) != 0) )
            /* copy dst string to return string */
            strcpy(string, dst);

        if ( malloc_flag )
            _free_crt(dst);

        return(string);

#else

        char * cp;

        for (cp=string; *cp; ++cp)
        {
            if ('A' <= *cp && *cp <= 'Z')
                *cp += 'a' - 'A';
        }

        return(string);

#endif
}