drive.cpp File Reference

#include <corecrt_internal.h>
#include <ctype.h>
#include <direct.h>
#include <errno.h>

Include dependency graph for drive.cpp:

Go to the source code of this file.

Functions
static int __cdecl	get_drive_number_from_path (wchar_t const *const path) throw ()
int __cdecl	_getdrive ()
int __cdecl	_chdrive (int const drive_number)

Function Documentation

_chdrive()

int __cdecl _chdrive

(

int const

drive_number

)

Definition at line 58 of file drive.cpp.

{
    if (drive_number < 1 || drive_number > 26)
    {
        _doserrno = ERROR_INVALID_DRIVE;
        _VALIDATE_RETURN(("Invalid Drive Index", 0), EACCES, -1);
    }
 
#pragma warning(suppress:__WARNING_UNUSED_ASSIGNMENT) // 28931 unused assignment of variable drive_letter
    wchar_t const drive_letter   = static_cast<wchar_t>(L'A' + drive_number - 1);
    wchar_t const drive_string[] = { drive_letter, L':', L'\0' };
 
    if (!SetCurrentDirectoryW(drive_string))
    {
        __acrt_errno_map_os_error(GetLastError());
        return -1;
    }
 
    return 0;
}

_getdrive()

int __cdecl _getdrive

(

void

)

Definition at line 25 of file drive.cpp.

{
    wchar_t cwd[MAX_PATH + 1] = { 0 };
 
    DWORD const cwd_length = GetCurrentDirectoryW(MAX_PATH + 1, cwd);
    if (cwd_length <= MAX_PATH)
    {
        return get_drive_number_from_path(cwd);
    }
 
    // Otherwise, we need more space for the path, so we'll need to dynamically
    // allocate a buffer:
    __crt_unique_heap_ptr<wchar_t> const heap_cwd(_calloc_crt_t(wchar_t, cwd_length + 1));
    if (heap_cwd.get() == nullptr)
    {
        errno = ENOMEM;
        return 0;
    }
 
    DWORD const heap_cwd_length = GetCurrentDirectoryW(cwd_length + 1, heap_cwd.get());
    if (heap_cwd_length == 0)
    {
        errno = ENOMEM;
        return 0;
    }
 
    return get_drive_number_from_path(heap_cwd.get());
}

Referenced by _tgetdcwd(), _tstat64(), cmd_setlocal(), get_drive_number_from_path(), test_utf8(), and throw().

get_drive_number_from_path()

static int __cdecl get_drive_number_from_path ( wchar_t const *const  path ) throw ( )

static

Definition at line 13 of file drive.cpp.

{
    if (path[0] == L'\0' || path[1] != L':')
        return 0;
 
    return __ascii_towupper(path[0]) - L'A' + 1;
}

Referenced by _getdrive().