Simple UNIX commands

Simple UNIX commands

ls Outputs a list of files and directory names.
cd Changes the current directory.
cp Copies the specified files from one directory to another or to another file.
mv Moves the specified files from one directory to another or to another file.
rm Deletes the specified files.
mkdir Creates a new directory.
rmdir Removes an empty directory.
exit Exits the current shell.
more Displays the contents of a text file page by page on screen.
man Dsiplays the on-line documentation (Manual pages) corresponding to a command.
cat Concationation of files, or outputting the contents of a file.
grep Searches within the specified files for a certain pattern.
passwd Changes a user's password.
ps Lists all running processes with their process ID.
kill Sends a signal to the specified process ID.
su Temporaily change the user ID, without having to repeat the login.

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ls

Lists the files found in the file system.

ls [flags] filelist

-A Shows all files including hidden files and does not show current (.) and parent directory (..).

-a Shows all files including hidden files and shows the current (.) and parent directory (..).

-C Columnar output, sorted down the columns.

-x Columnar output, sorted across the columns.

-d Treats each entry as a directory.

-l Gives the long listing - details about each file is displayed.

-t Sorts by the time last modified. Used with the -l flag.

-u Sorts by the time last accessed. Used with the -l flag.

-c Sorts by the time the i-node information last changed. Used with the -t flag.

-r Reverses the sort order.

-i Shows the i-node number of the ffile in the first column.

filelist - A space seperated list of files and directories to list
Suggested options

ls - Simplest output - just displays the normal files and directories.

ls -la - Displays the details about all the files.

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cd

Changes the current working directory.

cd dirname

dirname - Changes to an optional directory name. If no directory is specified, the user is returned to his home directory.

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cp

Copies files. You may copy one file to another, or a list of files to a directory.

cp source-file dest-file

cp source-list dest-directory

source-file - The file to copy
dest-file - The destination filename. This maybe a directory name, in which case the source file name is appended to the directory
source-list - A space seperated list of files to copy
dest-directory - The destination directory

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mv

Renames a file or moves it to a new direcory, or both. mv also allows you to rename a directory.

mv [flags] file1 file2

mv [flags] dir1 dir2

mv [flags] filelist dir

-f Normally mv prompts you if the destination file exists and write permissoins are turned off. This causes mv to move without prompting.

file1 - The source file name
file2 - The destination file name (new name)
dir1 - The source directory name
dir2 - The destination directory name (new name)
filelist - A space seperated list of files to move. Names are retained.
dir - The destination directory.

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rm

Removes files and intire directory structures from the file system.

rm [flags] filelist

-f Specifies forced mode. Normally rm prompts you if you don't have permissions to delete the file. This forces the file to be removed without your involvement.

-r Deletes the directories specified in filelist. Directories are only deleted if the -r flag is specified.

-i Specifies interactive mode. You are prompted before the removal takes place.

-- Indicates the end of all options.

filelist - A space seperated list of files you want to delete. It may contain directory names as well.

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mkdir

Creates directories.

mkdir [flags] dirnames

-m mode Sets the directory permissions to mode at the time of creation.

-p Creates all non-existant parent directories.

dirnames - The path of the directory to be created

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rmdir

Removes directories.

rmdir [flags] dirlist

-p Causes rmdir to delete any parent directories that also become empty.

-s Suppress the message when the -p option is active.

dirlist - A space seperated list of directory names. Directories must be empty to be deleted

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exit

Exits from the current shell.

exit

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more

More is a general purpose pager. It is used to view text files that scrolls off the screen.

more [flags] filenames

-n n is an integer used to set the window size - number of lines on the screen

-d Changes the default more prompt

-f Counts logical lines rather than screen lines

-r Shows carriage returns as ^M

-v Shows all control characters as ^x, where x is the character used to generate it.

-s Multiple blank lines are suppressed and treated as one.

-w Waits at the end of file fir usersupplied control to quit, rather than just exiting.

filelist - A space seperated list of file names.

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man

NOT YET DONE!!!

man

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cat

Concatenates files. This is sometimes used to display a file.

cat [flags] filelist

-s Suppresses messages about unreadable files.

-u Causes the output to be unbuffered.

-v Shows all control characters as ^x, where x is the character used to generate it.

-t Used with the -v option this causes tabs and formfeeds to be displayed in the ^x format.

-e Used with the -v option this causes newlines to be followed by a $ sign

filelist - A space seperated list of file names to be concatenated. If none is given then stdin is used.

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grep

NOT YET DONE!!!

grep

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passwd

Allows a user to change their passwd.

passwd username

username - Changes the passwd of the user username.

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ps

NOT YET DONE!!!

ps [flags]

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kill

Allows you to send a signal to a process that is currently running. Usually this command is used to cause the process to stop executing.

kill -signal pid

-signal The signal that is going to be sent.
pid The process ID of the process you want to send the signal to.

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su

NOT YET DONE!!!

su [flags]

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Page last updated by John-Lucas Brown 03-Apr-1997