Programming

Kev’s Command Prompt Cheat Sheet Article

    Kevin Yank
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    Over the years, I’ve received messages from many a distraught beginner who was stuck because the instructions they were following made reference to the dreaded MS-DOS Command Prompt. This increasingly well-hidden feature of Windows harkens back to the days when Windows was just a thin, 16-color veil over the very basic MS-DOS operating system.

    As a Web developer, there are a number of reasons you may need to use the command line in Windows. Open-source programs such as MySQL and Apache don’t always make all (or any!) of their functions available through the pretty icons and menus that Windows provides, trusting instead that developers like you and I will have a degree of command line savvy to see us through.

    To run the MS-DOS Command Prompt, click on its icon in the start menu. It may be in the main Programs list or under Accessories, and may be called MS-DOS Command Prompt or just Command Prompt, depending on which version of Windows you own. In any case, once you start it up, you’ll get an ugly black window. Scary, huh?

    The whole idea of the Command Prompt is you type commands after the prompt. Here’s some info to get you started with this mysterious utility:

    • Type commands as you would in a text editor. You can use the left and right arrow keys and delete or backspace just as you would in Notepad. Don’t reach for the mouse, though — the command prompt is a strictly keyboard-driven affair.
    • After each command, type the Enter key to execute it. Usually, a message will appear informing you of the outcome of the command you executed. Don’t feel bad if the message tells you that something was wrong with the command — displaying error messages is what the command prompt does best.
    • Up and down arrows can usually be used to recall previous commands to be edited and executed again.

    The command prompt itself tells you where you are on your system. For example, if your prompt looks like this:

    C:WINDOWS>

    it means that you are currently working in the WINDOWS folder on C: drive.

    To get a list of all the files and sub-folders in the current folder, type the dir command, which is short for directory, and press Enter. Here’s what this looks like when I do this (I’ll always show the part you type in bold, just so there’s no confusion):

    C:WINDOWS>dir
 Volume in drive C is WINDOWS ME 
 Volume Serial Number is 3436-18D4 
 Directory of C:WINDOWS
23/11/2001  05:09 PM    <DIR>          . 
23/11/2001  05:09 PM    <DIR>          .. 
23/11/2001  05:09 PM    <DIR>          SYSTEM 
23/11/2001  05:24 PM            21,520 WINSOCK.DLL 
... 
             249 File(s)     93,256,655 bytes
              27 Dir(s)   1,141,923,840 bytes free

    If your directory listing is too long to fit in the command prompt window (as will often be the case), type /p after the dir command (i.e. type dir /p and then press Enter). You can then view the directory listing a page at a time, and type any key to view the next page until you reach the end of the listing.

    The cd command is used to change your current folder (i.e. change directory). For example, if you’re in the C:WINDOWS folder, you can move to the C:WINDOWSSYSTEM directory by typing cd system and then Enter. Here’s how this looks on my computer:

    C:WINDOWS>cd system
C:WINDOWSSYSTEM>

    See how the prompt changes to indicate the directory we are now working in?

    We can return to the parent directory of the current directory (in this case, C:WINDOWS is the parent of C:WINDOWSSYSTEM) by typing cd .. because .. is a special name that always means "the parent directory of the current directory":

    C:WINDOWSSYSTEM>cd ..
C:WINDOWS>

    You can change which drive you’re working on by typing the drive name. For example, to move to D: drive, I do this:

    C:WINDOWS>d:

D:>

    See how we’re now in the root directory of D:? Now, if I had installed MySQL in D:Program FilesMySQL, I could go to the bin directory of my MySQL installation (D:Program FilesMySQL) like this:

    D:>cd "Program Files"
D:Program Files>cd MySQL
D:Program FilesMySQL>cd bin
D:Program FilesMySQLbin>

    Notice that I put quotes around the directory name Program Files because it contained a space. If I hadn’t done this, the command would not have worked. The above set of three commands could have been combined into a single command like this:

    D:>cd "Program FilesMySQLbin"
D:Program FilesMySQLbin>

    Now that you’re in your MySQL bin directory, you can look at the files it contains with the dir command:

    D:Program FilesMySQLbin>
 Volume in drive D is DATA1 
 Volume Serial Number is 18FA-3226 
 Directory of D:Program FilesMySQLbin 
04/12/2001  03:26 PM    <DIR>          .
04/12/2001  03:26 PM    <DIR>          .. 
24/11/2001  04:43 AM         1,110,016 mysqld-opt.exe 
24/11/2001  05:36 AM         1,990,656 mysqld-max.exe 
24/11/2001  05:30 AM         1,994,752 mysqld-max-nt.exe 
24/11/2001  05:17 AM         1,118,208 mysqld-nt.exe 
24/11/2001  04:12 AM         2,867,246 mysqld.exe 
24/11/2001  05:38 AM           274,432 isamchk.exe 
24/11/2001  05:39 AM           335,872 myisamchk.exe 
24/11/2001  05:40 AM           266,240 myisamlog.exe 
24/11/2001  05:41 AM           262,144 myisampack.exe 
24/11/2001  04:28 AM           278,578 mysql.exe
24/11/2001  04:28 AM           237,568 mysqladmin.exe 
24/11/2001  05:42 AM           237,568 mysqlbinlog.exe
21/10/2001  01:25 AM           334,712 mysqlc.exe 
24/11/2001  05:42 AM           229,376 mysqlcheck.exe 
24/11/2001  04:28 AM           241,664 mysqldump.exe 
24/11/2001  04:28 AM           225,280 mysqlimport.exe 
24/11/2001  04:29 AM           520,192 MySqlManager.exe 
24/11/2001  04:29 AM           229,376 mysqlshow.exe 
24/11/2001  05:44 AM            40,960 mysqlshutdown.exe
24/11/2001  05:45 AM            45,056 mysqlwatch.exe 
24/11/2001  05:45 AM           229,376 pack_isam.exe 
24/11/2001  05:46 AM           155,648 perror.exe 
24/11/2001  05:46 AM           172,032 replace.exe 
19/06/2000  03:51 AM               818 winmysqladmin.cnt 
03/11/2001  01:09 AM         1,167,872 winmysqladmin.exe 
19/06/2000  03:52 AM         1,856,816 WINMYSQLADMIN.HLP
              26 File(s)     16,422,458 bytes 
               2 Dir(s)   9,239,920,640 bytes free

    See all the .exe files? Running a program from the command prompt simply involves typing its name while you’re in the directory. So in the above example I’m now ready to run such commands as mysqld, mysqladmin and mysql.

    Oh, and when you’re done, you can exit a command prompt by typing exit.