WindowsXP-SP1/base/crts/crtw32/dos/drive.c
2020-09-30 16:53:49 +02:00

139 lines
3.9 KiB
C

/***
*drive.c - get and change current drive
*
* Copyright (c) 1989-2001, Microsoft Corporation. All rights reserved.
*
*Purpose:
* This file has the _getdrive() and _chdrive() functions
*
*Revision History:
* 06-06-89 PHG Module created, based on asm version
* 03-07-90 GJF Made calling type _CALLTYPE1, added #include
* <cruntime.h> and fixed copyright. Also, cleaned up
* the formatting a bit.
* 07-24-90 SBM Removed '32' from API names
* 09-27-90 GJF New-style function declarators.
* 12-04-90 SRW Changed to include <oscalls.h> instead of <doscalls.h>
* 12-06-90 SRW Added _CRUISER_ and _WIN32 conditionals.
* 05-10-91 GJF Fixed off-by-1 error in Win32 version and updated the
* function descriptions a bit [_WIN32_].
* 05-19-92 GJF Revised to use the 'current directory' environment
* variables of Win32/NT.
* 06-09-92 GJF Use _putenv instead of Win32 API call. Also, defer
* adding env var until after the successful call to
* change the dir/drive.
* 04-06-93 SKS Replace _CRTAPI* with __cdecl
* 11-24-93 CFW Rip out Cruiser.
* 11-24-93 CFW No longer store current drive in CRT env strings.
* 02-08-95 JWM Spliced _WIN32 & Mac versions.
* 07-01-96 GJF Replaced defined(_WIN32) with !defined(_MAC). Also,
* detab-ed and cleaned up the format a bit.
* 12-17-97 GJF Exception-safe locking.
* 05-17-99 PML Remove all Macintosh support.
*
*******************************************************************************/
#include <cruntime.h>
#include <oscalls.h>
#include <mtdll.h>
#include <internal.h>
#include <msdos.h>
#include <errno.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
/***
*int _getdrive() - get current drive (1=A:, 2=B:, etc.)
*
*Purpose:
* Returns the current disk drive
*
*Entry:
* No parameters.
*
*Exit:
* returns 1 for A:, 2 for B:, 3 for C:, etc.
* returns 0 if current drive cannot be determined.
*
*Exceptions:
*
*******************************************************************************/
int __cdecl _getdrive (
void
)
{
ULONG drivenum;
UCHAR curdirstr[_MAX_PATH];
drivenum = 0;
if (GetCurrentDirectory(sizeof(curdirstr), curdirstr))
if (curdirstr[1] == ':')
drivenum = toupper(curdirstr[0]) - 64;
return drivenum;
}
/***
*int _chdrive(int drive) - set the current drive (1=A:, 2=B:, etc.)
*
*Purpose:
* Allows the user to change the current disk drive
*
*Entry:
* drive - the number of drive which should become the current drive
*
*Exit:
* returns 0 if successful, else -1
*
*Exceptions:
*
*******************************************************************************/
int __cdecl _chdrive (
int drive
)
{
int retval;
char newdrive[3];
if (drive < 1 || drive > 31) {
errno = EACCES;
_doserrno = ERROR_INVALID_DRIVE;
return -1;
}
#ifdef _MT
_mlock( _ENV_LOCK );
__try {
#endif
newdrive[0] = (char)('A' + (char)drive - (char)1);
newdrive[1] = ':';
newdrive[2] = '\0';
/*
* Set new drive. If current directory on new drive exists, it
* will become the cwd. Otherwise defaults to root directory.
*/
if ( SetCurrentDirectory((LPSTR)newdrive) )
retval = 0;
else {
_dosmaperr(GetLastError());
retval = -1;
}
#ifdef _MT
}
__finally {
_munlock( _ENV_LOCK );
}
#endif
return retval;
}