Shree M. & N. Virani Science College. DOS Commands. By Milan Kothari. Yogidham, Kalawad Road, Rajkot 5 Ph :

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1 DOS Commands By Milan Kothari

2 What Is Dos? DOS or the Disk Operating System designed to operate personal computer is basically a collection of software programs that help to manage the personal computer s resources, that is, system board, printers, keyboard, visual display unit etc. and direct the fundamental computer operations. A computer system minus the operating system is a useless piece of machine. With an operating system you are able to interact with the computer and instruct it what to do. To operate the personal computer or compatibles either MS-DOS or PC-DOS is required. MS- DOS is the registered trademark of MICROSOFT CORPORATION and PC-DOS is the registered trademark of IBM CORPORATION. Internal command The internal command is a command, which is present in the system. It is a part of the COMMAND.COM Program. If you type in any of the internal commands such as COPY irrespective of which disk drive is operational, you will still be able to use the COPY command. Putting it simply once the dos get resident in the memory for internal command usage the system does not refer to the dos available on the disk, but takes the required instruction from the memory resident portion of the DOS. External command External commands are those, which form part of the MS-DOS, command structure but are not present in the system when MS-DOS is operational. Before an external command can be put to use, it is first loaded. As a result you must have the path set to MS-DOS directory in the computer to make use of the external commands. FORMAT, DISKCOPY etc. is examples of the external commands. Thus external commands are part of the standard MS-DOS system but are not memory resident. Wild card character Wild card also called a global characters are special characters that can be used in a filename to make the name ambiguous. On using these special characters, the filename you are using can match more than one file on the disk. The question mark (?) and the asterisk mark (*) are two DOS wild card characters. DOS interpret the: Question mark to imply: match any one character in the filename. Whereas Asterisk means: match any number of characters in the file name. Both? And * will match places where characters are not specified in a filename. Combination of? s and * s can also be used. If you want to copy all your files from one directory to another directory starting from A letter and ending with any two letter and extension is.txt type the following command C:\>copy A??.TXT c:\cp1 If you want to copy all your files from one directory to another directory starting with any one letter and ending with.txt extension type the following command C:\>copy?.TXT c:\cp1 If you want to copy all your files from one directory to another directory having.txt extension type the following command C:\>copy *.TXT c:\cp1 If you want to copy all your files from one directory to another directory starting with A letter type the following command

3 C:\>copy A*.* c:\cp1 If you want to copy all your files from one directory to another directory starting from A letter and ending with any one letter type the following command C:\>copy A?*.* c:\cp1 FILES (config.sys) Assign the amount of memory that is to be set aside for file handles. The command is to be used only in a config.sys file. Format: Files = xx XX is the amount of memory for a control block used in managing file handles. PRINT (external) Use the command to print a text file while you are using other MS-DOS commands. Format : PRINT [/d: device] [/b: size] [/u:ticks1] [/m:ticks2] [/s:ticks3] [/q: qsize] [/t] [[drive:][path]filename[ ]] [Drive:] [Path] filename: these parameters specify the location and name of a file or set of files that need to be printed. /D : this switch will specify the name of the print device. /B : this switch will set the size (in bytes) of the internal buffer, which is used to store data before it is sent to the printer. /U : ticks-use the switch to specifies the maximum number of clock ticks print is to wait for a printer to be available (clock ticks occur about 18 times per second). If the printer is not available within the time specified, the job does not print. /M : ticks2-this switch will specify the maximum number of clock ticks print can take to print a character on the printer. /S : ticks-this switch will specify the number of clock ticks the MS-DOS scheduler allocates for background printing. /Q : qsize-use the switch to specify the maximum number of files allowed in the printer queue. /T : this switch removes all files from the print queue. To view the status of the print queue type the following C:\>PRINT COPY (internal) Copies one or more files to another location. Frmat : COPY [/A /B] source [/A /B] [+ source [/A /B] [+...]] [destination [/A /B]] [/V] [/Y /-Y] Source : Specifies the file or files to be copied. /A : Indicates an ASCII text file. /B : Indicates a binary file. Destination : Specifies the directory and/or filename for the new file(s). /V : verifies that new files are written correctly.

4 /Y : Suppresses prompting to confirm you want to overwrite an existing destination file. /-Y : Causes prompting to confirm you want to overwrite an existing destination file. The switch /Y may be preset in the COPYCMD environment variable. This may be overridden with /-Y on the command line To append files, specify a single file for destination, but multiple files For source (using wildcards or file1+file2+file3 format). XCOPY: To copy all of a directory s files and subdirectories, you should use the XCOPY command. COPY CON : Use to create a new file. C:\>COPY CON file1.txt After you type this command and press ENTER, MS-DOS copies everything you type to the file file1.txt. When you are finished typing, either press F6 key or CTRL+Z to indicate that you want to end the file. The CTRL+Z character will appear on the screen as ^Z. Copy one file to another file type the following command C:\>COPY file1.txt file2.txt Using wild card character if you want to copy all files from one directory to another directory type the following command C:\>COPY c:\dir1\*.* c:\dir2 DIR (internal) Use the command to display a list of the files and/or subdirectories in the specified path. Format : DIR [drive:][path][filename] [/p] [/w] [/a [[:] attributes]] [/o [[:]sort order]][/s][/b][/l][/c] /P : Pauses after each screenful of information(display page wise listing). /W : Uses wide list format. /A : Displays files with specified attributes. Attributes D Directories R Read-only files H Hidden files A Files ready for archiving S System files - Prefix meaning not /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 (earliest first) G Group directories first - Prefix to reverse order A By Last Access Date (earliest first) /S : Displays files in specified directory and all subdirectories. /B : Uses bare format (no heading information or summary). /L : Uses lowercase. /V : Verbose mode. /4 : Displays year with 4 digits (ignored if /V also given). To display list of all files and subdirectories page wise type the following command C:\>DIR /p To display list of all files and subdirectories in alphabetical order type the following command C:\>DIR /o:n

5 DATE (internal) To Displays or sets the system dates. Format : DATE [date] Type DATE without parameters to display the current date setting and a prompt for a new one. Press ENTER to keep the same date. TIME (internal) To Displays or sets the system time. Format : TIME [time] Type TIME with no parameters to display the current time setting and a prompt for a new one. Press ENTER to keep the same time. FORMAT (external) Formats a disk for use with MS-DOS. Format : FORMAT drive: [/V[:label]] [/Q] [/F:size] [/C] FORMAT drive: [/V[:label]] [/Q] [/T:tracks /N:sectors] [/C] FORMAT drive: [/V[:label]] [/Q] [/1] [/4] [/C] FORMAT drive: [/Q] [/1] [/4] [/8] [/C] /V: label - Specifies the volume label. /Q : Performs a quick format. /F: size-specifies the size of the floppy disk to format (such as 160, 180, 320, 360, 720, 1.2, 1.44, 2.88). /T: tracks - Specifies the number of tracks per disk side. /N: sectors - Specifies the number of sectors per track. /1 : Formats a single side of a floppy disk. /4 : Formats a 5.25-inch 360K floppy disk in a high-density drive. /8 : Formats eight sectors per track. /C : Tests clusters that are currently marked "bad." LABEL (external) Creates, changes, or deletes the volume label of a disk. Format : LABEL [drive:][label] ATTRIB (external) Displays or changes file attributes. Format : ATTRIB [+R -R] [+A -A] [+S -S] [+H -H] [[drive:][path]filename] [/S] + Sets an attribute. - Clears an attribute. R : Read-only file attribute. A : Archive file attribute. S : System file attribute.

6 H : Hidden file attribute. /S : Processes files in all directories in the specified path. To set a read-only attribute to a file abc.txt type following C:\>ATTRIB +r abc.txt CHDIR OR CD (internal) Displays the name of or changes the current directory. Format : CHDIR [drive:][path] CHDIR [..] CD [drive:][path] CD [..].. Specifies that you want to change to the parent directory. Type CD drive: to display the current directory in the specified drive. Type CD without parameters to display the current drive and directory. DEL OR DELETE (internal) Deletes one or more files. Format : DEL [drive:][path] filename [/P] ERASE [drive:][path] filename [/P] [Drive:][Path]filename: specifies the file(s) to delete. Specify multiple files by using wildcards. /P: Prompts for confirmation before deleting each file. To delete abc.txt file type the following command C:\>DEL abc.txt To delete all files from directory then use wild card character C:\cp1\>DEL *.* FIND (external) To Searches for a text string in a file or files. Format : FIND [/V] [/C] [/N] [/I] "string" [[drive:][path]filename[...]] /V : Displays all lines NOT containing the specified string. /C : Displays only the count of lines containing the string. /N : Displays line numbers with the displayed lines. /I : Ignores the case of characters when searching for the string. "String : Specifies the text string to find. [Drive:][Path] filename: Specifies a file or files to search. If a pathname is not specified, FIND searches the text typed at the prompt or piped from another command. To display all lines from file1.txt in the specified order that contains the string programming then type C:\>FIND programming file1.txt

7 RENAME OR REN (internal) Renames a file/directory or files/directories. Format:RENAME[drive:][path][directoryname1 filename1] [directoryname2 filename2] REN [drive:][path][directoryname1 filename1][directoryname2 filename2] Note that you cannot specify a new drive or path for your destination. To rename a file named temp.txt to area.txt type the following command C:\>REN temp.txt area.txt EXIT Quits the COMMAND.COM program (command interpreter). Format : EXIT CLS Clears the screen. Format : CLS SORT (external) Sorts input and writes results to the screen, a file, or another device Format: SORT[/R][/+n][[drive1:][path1]filename1][>[drive2:][path2]filename2] [command ] SORT [/R] [/+n] [> [drive2:][path2]filename2] /R : Reverses the sort order; that is, sorts Z to A, then 9 to 0. /+N : Sorts the file according to characters in column n. [drive1:][path1]filename1 : Specifies file(s) to be sorted [drive2:][path2]filename2 : Specifies a file where the sorted input is to be stored. command : Specifies a command whose output is to be sorted. To sort the content of the file temp.txt in reverses order type the following command C:\>SORT /r temp.txt PROMPT (internal) Changes the Windows command prompt. Format : PROMPT [text] Text Specifies a new command prompt. Prompt can be made up of normal characters and the following special codes: $Q = (equal sign) $$ $ (Dollar sign) $T Current time $D Current date $P Current drive and path

8 $V Windows version number $N Current drive $G > (greater-than sign) $L < (less-than sign) $B (pipe) $H Backspace (erases previous character) $E Escape code (ASCII code 27) $_ Carriage return and linefeed The following command sets the user prompt to $ C:\>PROMPT $$ The following command display the current path as well as the system prompt C:\>PROMPT $P$G MKDIR OR MD (internal) Creates a directory. Format : MKDIR [drive:]path MD [drive:] path To create a directory cp1 type the following command C:\>MD cp1 PATH (internal) Displays or sets a search path for executable files. Format : PATH [[drive:]path[;...]] PATH ; Type PATH ; to clear all search-path settings and direct Windows to search Only in the current directory. Type PATH without parameters to display the current path. RMDIR OR RD (internal) Removes (deletes) a directory. Format : RMDIR [drive:]path RD [drive:] path It is necessary that prior to directory deletion, you must delete its files and subdirectory. To remove cp1 directory type the following C:\>RD cp1 CHKDSK (external) Checks a disk and displays a status report. Format : CHKDSK [drive:][[path]filename] [/F] [/V] [Drive:][Path]: Specifies the drive and directory to check. Filename: Specifies the file(s) to check for fragmentation. /F : Fixes errors on the disk. /V : Displays the full path and name of every file on the disk.

9 Type CHKDSK without parameters to check the current disk. Instead of using CHKDSK, try using SCANDISK. SCANDISK can reliably detect And fix a much wider range of disk problems.