Unix Command
In the table below we summarize the more frequently used commands on a Unix system. In this table, as in general, for most Unix commands, file, could be an actual file name, or a list of file names, or input/output could be redirected to or from the command.Unix CommandsCommand/Syntaxawk/nawk [options] filescan for patterns in a file and process the resultscat [options] fileconcatenate (list) a filecd [directory]change directorychgrp [options] group filechange the group of the filechmod [options] file change file or directory access permissionschown [options] owner filechange the ownership of a file;
chsh (passwd -e/-s)
username login_shellchange the user's login shell (often only by the superuser)cmp [options] file1 file2compare two files and list where differences occur (text or binary files)compress [options] filecompress file and save it as file.Zcp [options] file1 file2copy file1 into file2; file2 shouldn't already exist.
This command creates or overwrites file2.cut (options) [file(s)]cut specified field(s)/character(s) from lines in file(s)date [options]report the current date and timedd [if=infile] [of=outfile]
[operand=value]copy a file, converting between ASCII and EBCDIC or
swapping byte order, as specifieddiff [options] file1 file2compare the two files and display the differences (text files only)df [options] [resource]report the summary of disk blocks and inodes free and in usedu [options]
[directory or file]report amount of disk space in useecho [text string]echo the text string to stdouted or ex [options] fileUnix line editorsemacs [options] filefull-screen editorexpr argumentsevaluate the arguments. Used to do arithmetic, etc. in the shell.file [options] fileclassify the file typefind directory [options]
[actions]find files matching a type or patternfinger [options]
user[@hostname]report information about users on local and remote machinesftp [options] hosttransfer file(s) using file transfer protocolgrep [options] 'search string' argumentegrep [options] 'search string' argumentfgrep [options] 'search string' argumentsearch the argument (in this case probably a file) for
all occurrences of the search string, and list them.gzip [options] filegunzip [options] filezcat [options] filecompress or uncompress a file. Compressed files are stored with a .gz endinghead [-number] filedisplay the first 10 (or number of) lines of a filehostnamedisplay or set (super-user only) the name of the current machinekill [options] [-SIGNAL]
[pid#] [%job]send a signal to the process with the process id number (pid#) or
job control number (%n). The default signal is to kill the process.ln [options] source_file targetlink the source_file to the targetlpq [options]lpstat [options]show the status of print jobslpr [options] filelp [options] fileprint to defined printerlprm [options]cancel [options]remove a print job from the print queuels [options] [directory or file]list directory contents or file permissionsmail [options] [user]mailx [options] [user]Mail [options] [user]simple email utility available on Unix systems.
Type a period as the first character on a new line to send message out,
question mark for help.man [options] commandshow the manual (man) page for a commandmkdir [options] directorymake a directorymore [options] fileless [options] filepg [options] filepage through a text filemv [options] file1 file2move file1 into file2od [options] fileoctal dump a binary file, in octal, ASCII, hex, decimal, or character mode.passwd [options]set or change your passwordpaste [options] filepaste field(s) onto the lines in filepr [options] filefilter the file and print it on the terminalps [options]show status of active processespwdprint working (current) directoryrcp [options] hostnameremotely copy files from this machine to another machinerlogin [options] hostnamelogin remotely to another machinerm [options] fileremove (delete) a file or directory (-r recursively deletes the directory
and its contents)(-i prompts before removing files)rmdir [options] directoryremove a directoryrsh [options] hostnameremote shell to run on another machinescript filesaves everything that appears on the screen to file until exit is executedsed [options] filestream editor for editing files from a script or from the command linesort [options] filesort the lines of the file according to the options chosensource file. fileread commands from the file and execute them
in the current shell. source: C shell, .: Bourne shell.strings [options] filereport any sequence of 4 or more printable characters ending in
or . Usually used to search binary files for ASCII strings.stty [options]set or display terminal control optionstail [options] filedisplay the last few lines (or parts) of a filetar key[options] [file(s)]tape archiver--refer to man pages for details on creating, listing,
and retrieving from archive files. Tar files can be stored on tape or disk.tee [options] filecopy stdout to one or more filestelnet [host [port]]communicate with another host using telnet protocoltouch [options] [date] filecreate an empty file, or update the access time of an existing filetr [options] string1 string2translate the characters in string1 from stdin into those in string2 in stdoutuncompress file.Zuncompress file.Z and save it as a fileuniq [options] fileremove repeated lines in a fileuudecode [file]decode a uuencoded file, recreating the original fileuuencode [file] new_nameencode binary file to 7-bit ASCII, useful when sending via email,
to be decoded as new_name at destinationvi [options] filevisual, full-screen editorwc [options] [file(s)]display word (or character or line) count for file(s)whereis [options] commandreport the binary, source, and man page locations for the command namedwhich command reports the path to the command or the shell alias in usewho or wreport who is logged in and what processes are runningzcat file.Zconcatenate (list) uncompressed file to screen, leaving file compressed on disk