Dir (命令)

dir （directory，目錄）是一個條列檔案及目錄的命令行界面指令，在CP/M、VMS、DOS、OS/2、Singularity及Microsoft Windows等作業系統中都有此指令。
dir指令基本上會列出目錄中的檔案及子目錄的名稱，也可以列出其檔案大小，建立時間等相關資訊，並且列出所在的磁碟機、可用空間等資訊。dir指令也可以尋找其檔案名稱符合特定條件的檔案。

**用法範例**
以下的範例是在Windows 7中給dir指令，沒有指令列引數時的輸出：
C:\Users\Public\Pictures\Sample Pictures>dir
Volume in drive C is System
Volume Serial Number is C8D0-76E2

Directory of C:\Users\Public\Pictures\Sample Pictures

14-07-2009  06:41              .
14-07-2009  06:41              ..
14-07-2009  06:52           879,394 Chrysanthemum.jpg
14-07-2009  06:52           845,941 Desert.jpg
14-07-2009  06:52           595,284 Hydrangeas.jpg
14-07-2009  06:52           775,702 Jellyfish.jpg
14-07-2009  06:52           780,831 Koala.jpg
14-07-2009  06:52           561,276 Lighthouse.jpg
14-07-2009  06:52           777,835 Penguins.jpg
14-07-2009  06:52           620,888 Tulips.jpg
8 File(s)      5,837,151 bytes
2 Dir(s)  57,925,980,160 bytes free

C:\Users\Public\Pictures\Sample Pictures>dir /w
Volume in drive C is System
Volume Serial Number is C8D0-76E2

Directory of C:\Users\Public\Pictures\Sample Pictures

.                 ..                Chrysanthemum.jpg   Desert.jpg          Hydrangeas.jpg      Jellyfish.jpg
Koala.jpg           Lighthouse.jpg      Penguins.jpg        Tulips.jpg
8 File(s)      5,837,151 bytes
2 Dir(s)  57,925,992,448 bytes free

C:\Users\Public\Pictures\Sample Pictures>

**選項及指令列引數**
以下是Microsoft Windows下，dir指令的選項及指令列引數
DIR drive:pathfilename /A:attributes /B /C /D /L /N
/O:sortorder /P /Q /R /S /T:timefield /W /X /4
drive:pathfilename
Specifies drive, directory, and/or files to list.
/A          Displays files with specified attributes.
attributes   D  Directories                R  Read-only files
H  Hidden files               A  Files ready for archiving
S  System files               I  Not content indexed files
L  Reparse Points             -  Prefix meaning not
/B          Uses bare format (no heading information or summary).
/C          Display the thousand separator in file sizes.  This is the
default.  Use /-C to disable display of separator.
/D          Same as wide but files are list sorted by column.
/L          Uses lowercase.
/N          New long list format where filenames are on the far right.
/O          List by files in sorted order.
sortorder    N  By name (alphabetic)       S  By size (smallest first)
E  By extension (alphabetic)  D  By date/time (oldest first)
G  Group directories first    -  Prefix to reverse order
/P          Pauses after each screenful of information.
/Q          Display the owner of the file.
/R          Display alternate data streams of the file.
/S          Displays files in specified directory and all subdirectories.
/T          Controls which time field displayed or used for sorting timefield.
C  Creation
A  Last Access
W  Last Written
/W          Uses wide list format.
/X          This displays the short names generated for non-8dot3 file names.  The format is that of /N with the
name inserted before the long name.  If no short name is present, blanks are displayed in its place.
/4          Displays four-digit years.
選項可以放在DIRCMD環境變數中，若要關閉現有的設定，可以在選項前加上-，例如/-W。

**Unix**
dir不是Unix指令，Unix有類似的指令ls，不過GNU/Linux作業系統中有dir指令，等效於ls -C -b。

**相關條目**
MS-DOS命令列表

**參考資料==