Unix/Linux Command Reference .com

File Commandsls – directory listingls -al – formatted listing with hidden filescd dir - change directory to dircd – change to homepwd – show current directorymkdir dir – create a directory dirrm file – delete filerm -r dir – delete directory dirrm -f file – force remove filerm -rf dir – force remove directory dir *cp file1 file2 – copy file1 to file2cp -r dir1 dir2 – copy dir1 to dir2; create dir2 if it doesn't existmv file1 file2 – rename or move file1 to file2if file2 is an existing directory, moves file1 into directory file2ln -s file link – create symbolic link link to filetouch file – create or update filecat > file – places standard input into filemore file – output the contents of filehead file – output the first 10 lines of filetail file – output the last 10 lines of filetail -f file – output the contents of file as it grows, starting with the last 10 lines

Process Managementps – display your currently active processestop – display all running processeskill pid – kill process id pidkillall proc – kill all processes named proc *bg – lists stopped or background jobs; resume a stopped job in the backgroundfg – brings the most recent job to foregroundfg n – brings job n to the foreground

File Permissionschmod octal file – change the permissions of file to octal, which can be found separately for user, group, and world by adding:

● 4 – read (r)● 2 – write (w)● 1 – execute (x)

Examples:chmod 777 – read, write, execute for allchmod 755 – rwx for owner, rx for group and worldFor more options, see man chmod.

SSHssh user@host – connect to host as userssh -p port user@host – connect to host on port port as userssh-copy-id user@host – add your key to host for user to enable a keyed or passwordless login

Searchinggrep pattern files – search for pattern in filesgrep -r pattern dir – search recursively for pattern in dircommand | grep pattern – search for pattern in the output of commandlocate file – find all instances of file

System Infodate – show the current date and timecal – show this month's calendaruptime – show current uptimew – display who is onlinewhoami – who you are logged in asfinger user – display information about useruname -a – show kernel informationcat /proc/cpuinfo – cpu informationcat /proc/meminfo – memory informationman command – show the manual for commanddf – show disk usagedu – show directory space usagefree – show memory and swap usagewhereis app – show possible locations of appwhich app – show which app will be run by default

Compressiontar cf file.tar files – create a tar named file.tar containing filestar xf file.tar – extract the files from file.tartar czf file.tar.gz files – create a tar with Gzip compressiontar xzf file.tar.gz – extract a tar using Gziptar cjf file.tar.bz2 – create a tar with Bzip2 compressiontar xjf file.tar.bz2 – extract a tar using Bzip2gzip file – compresses file and renames it to file.gzgzip -d file.gz – decompresses file.gz back to file

Networkping host – ping host and output resultswhois domain – get whois information for domaindig domain – get DNS information for domaindig -x host – reverse lookup hostwget file – download filewget -c file – continue a stopped download

InstallationInstall from source:./configuremakemake installdpkg -i pkg.deb – install a package (Debian)rpm -Uvh pkg.rpm – install a package (RPM)

ShortcutsCtrl+C – halts the current commandCtrl+Z – stops the current command, resume with fg in the foreground or bg in the backgroundCtrl+D – log out of current session, similar to exitCtrl+W – erases one word in the current lineCtrl+U – erases the whole lineCtrl+R – type to bring up a recent command!! - repeats the last commandexit – log out of current session

* use with extreme caution.