Linux Commands
Linux Commands
| Linux Commands | ||
|---|---|---|
| Command Name | Description | Example |
| File/Directory | ||
| ls | List files | ls -l ls -alrt *.html |
| ls -al | formatted listing with hidden files | ls -al file.htm |
| cp | Copy files | cp sourcefile destinationfile |
| cp -r | Copy directory, create destination directory if it doesn’t exist | cp -r sourcedir destinationdir cp -r file* subdir/ |
| mv | Move/rename files | mv sourcefile destination file mv file* ubdir/ |
| rm | Remove/delete files | rm filename |
| rm -r | Remove/delete directory | rm -r directory |
| rm -f | Force to remove file | rm -f *.aux |
| rm -rf | Force to remove directory | rm -rf subdir/ |
| ln | Link files | ln |
| ln -s | Create symbolic link to file | ln -s file link |
| cd | Change Directory to home | cd |
| cd dir | Change directory to directory | cd ~/2350/hw cd bin |
| pwd | show Present Working Directory | pwd |
| mkdir | Make new Directory | mkdir 2005fall |
| rmdir | Remove/delete Directory | rmdir 1995fall |
| touch | create or update file | touch file.txt |
| File Viewing | ||
| cat | Display text contents | cat file1.txt file2.txt file3.txt |
| less | page through files | less |
| head | output first few lines of file | head -5 file.txt |
| tail | output last few lines of file | tail -5 file.txt |
| tail -f | output the contents of files as it grows, starting with last 10 lines | tail -f filename |
| nl | Number Lines | nl |
| od | view binary data | od |
| xxd | view binary data | xxd |
| gv | view postscript/pdf files | gv |
| xdvi | view TeX DVI files | xdvi |
| more | output the contents of the file | more filename |
| echo | Print to screen | echo “This is output” |
| strings | Text embedded in binary | strings a.out |
| File Creation and Edition | ||
| emacs | Text editor | emacs file.tex |
| vim | Text editor | vim file.tex |
| vi | Text editor | vi file.txt |
| nedit | Text editor | nedit file.txt |
| pico | Text editor | pico file.txt |
| latex | Compiles DVI documents | |
| pdflatex | Compiles PDF documents | |
| umask | set default file protections | umask |
| soffice | edit word/excel/powerpoint docs | soffice |
| abiword | edit word documents | abiword |
| gnumeric | edit excel documents | gnumeric |
| File Properties | ||
| stat | Display file attribute | stat |
| wc | Word Count – count bytes/words/lines | wc file.txt |
| file | identify File Types | file * |
| touch | Change file timestamps | touch |
| File Permission | ||
| chown | Change file Owner | chown |
| chgrp | Change group ownership | chgrp appm2350 index.htm |
| chmod OwnerGroupWorld | Change file permissions (4-read, 2-write, 1-execute) | chmod 754 file.htm (rwx for Owner, rx for Group and r for |
| chattr | Change advanced file Attributes | chattr |
| lsattr | List advanced file Attributes | lsattr |
| File Location | ||
| find | locate files | find |
| locate | find all instances of filename | locate filename |
| slocate | locate files via index | slocate |
| which | show which application or file will be run by default | which application/filename |
| whereis | show possible locations of apps/files | whereis application/filename |
| grep pattern | search for ‘pattern’ in files | grep pattern files |
| grep -r pattern | search recursively for pattern in dir | grep -r pattern dir |
| command | grep pattern | search for pattern in the output of command | |
| System Information | ||
| date | show the current date and time | date |
| cal | show this month’s calendar | cal 12 2005 |
| uptime | show current | uptime |
| w | display who is online | w |
| uname -a | show kernel information | |
| cat /proc/cpuinfo | show cpu information | |
| cat /proc/meminfo | show memory infomation | |
| man | show manual for command man ls | man -k editor |
| free | show memory and swap usage | free |
| File/Text Manipulation | ||
| grep | Find word/string | grep keyword file1 file2 file3 |
| cut | extract columns | cut |
| paste | append columns | paste |
| tr | Translate characters | tr |
| sort | Sort lines | sort -r -n file.txt |
| uniq | locate identical lines | uniq |
| tee | copy stdin to a file and to stdout simultaneously | tee |
| File Compression and Compilers | ||
| gzip | compress GNU files & rename it | gzip file.tar (new name file.gz) |
| gzip -d | decompress file.gz back to file | gzip -d file.gz |
| gunzip | Uncompres files | gunzip file.tar.gz |
| compress | Compress Unix files | compress |
| bzip2 | compress BZip2 files | bzip2 |
| zip | compress Windows files | zip |
| tar cf | Creates a tar named file.tar contains files | tar cf file.tar file1 file2 file3 file4 |
| tar xf | Extract the files from file.tar | tar xf file.tar |
| tar czf | Create a tar with Gzip compression | tar czf file.tar.gz files |
| tar xzf | Extract a tar using Gzip | tar xzf file.tar.gz |
| tar cjf | Create a tar with Bzip2 compression | tar cjffile.tar.bz2 |
| tar xjf | Extract a tar using Bzip2 | tar xjffile.tar.bz2 |
| cc | c++ gcc g++ C and C++ compilers | cc -o myprogramprogA.c |
| f77 | f90 f95 Fortran compilers | f90 -o myprogram progA.f90 |
| File Comparision | ||
| diff | compare files line by line | diff file1.txt file2.txt |
| comm | Compare sorted files | comm |
| cmp | Compare files byte by byte | cmp |
| md5sum | compute checksums | md5sum |
| Disks and File Systems | ||
| df | show Disk Free space | df |
| mount | make disk accessible | mount |
| fsck | Check a disk for errors | fsck |
| sync | flush disk caches | sync |
| du | measure Disk Usage | du -k |
| Backup and Remote Storage | ||
| mt | Control a tape drive | mt |
| dump | back up a disk | dump |
| restore | Restore a dump | restore |
| tar | read/write Tape Archives | tar |
| cdrecord | burn a CD | cdrecord |
| rsync | mirror a set of files | rsync |
| Printing | ||
| lpr | Print files | lpr |
| lpq | view Print Queue | lpq |
| lprm | Remove Print jobs | lprm |
| Spelling Operations | ||
| look | Look up spelling | lookstri |
| aspell | check Spelling interactively | aspell |
| spell | Find misspelled words | spell file.txt |
| Process Management | ||
| ps | list all Processes | ps -ef |
| w | list user’s processes | w |
| uptime | view the system load | uptime |
| top | display/monitor running processes | top |
| xload | monitor system Load | xload |
| free | display Free memory | free |
| kill | Terminate processes | killpid (pid=process id/no.) |
| kill all | Kill All process by same name | kill all ProcessName |
| nice | set process priorities | nice ./a.out |
| renice | Change process priorities | renice |
| bg | lists stopped or Background | jobs |
| fg | brings the most recent job to foregrond | fg n (n=job name/no.) |
| jobs | In current shell | jobs |
| Job Scheduling | ||
| sleep | wait for some time | sleep |
| watch | run programs at set intervals | watch |
| at | schedule a job | at |
| crontab | schedule repeated jobs | crontab |
| adduser | Adds a new user to the system | adduser username |
| Hosts/Users | ||
| uname | print system information | uname |
| hostname | print the system’s Hostname | hostname |
| whoami | Who you are logged in as | whoami |
| finger | Display information about user | finger username |
| passwd | Change password | passwd |
| w who whoami | User identities | w who whoami |
| Networking | ||
| ifconfig | set/display network information | ifconfig |
| host | look up DNS | host |
| whois | look up domain registrants | whois domainname |
| dig | get DNS information | dig domainname |
| Reverse lookup host | dig -x hostname | |
| ping | Check if host is reachable | ping hostname |
| traceroute | view network path to a host | traceroute |
| ssh | Securely log into remote hosts | ssh [email protected] |
| Connect to host on ‘port’ as user | ssh -p port [email protected] | |
| Add your key to host for user to enable a keyed/passwordless login | ssh -copy [email protected] | |
| ssh ssa.ccny.cuny.edu -l username | ||
| telnet | log into remote hosts | telnet |
| scp | Securely Copy files between hosts | scp myfile ssa.ccny.cuny.edu:subdir/file8 |
| sftp | Securely copy files between hosts | sftp |
| ftp | copy files between hosts | ftp |
| evolution | GUI email client | evolution |
| mutt | text based email client | mutt |
| minimal email client | ||
| mozilla | web browser | mozilla |
| lynx | text only web browser | lynx |
| wget | retrieve/download web pages/files | wget filename |
| Continue a stopped download | wget -c filename | |
| slrn | read Usenet news | slrn |
| gaim | instant messaging/IRC | gaim |
| talk | Linux/Unix chat | talk |
| write | send messages to terminal | write |
| mesg | prohibit talk/write | mesg |
| pine | pine | |
| mailx | mailx [email protected] | |
| Audio/Video | ||
| grip | play CDs and Rip MP3s | grip |
| xmms | play audio files | xmms |
| cdparanoia | rip audios | cdparanoia |
| audacity | edit audios | audacity |
| xcdroast | burn CDs | xcdroast |
| Installation | ||
| ./configure | ./configure | |
| make install | Install from source | |
| dpkg -i | Install a package (Debian) | dpkg -i pkg.deb |
| rpm -Uvh | Install a package (RPM) | rpm -Uvhpkg.rpm |
| Shortcuts | ||
| Ctrl+C | halts the current command | |
| Ctrl+Z | stops the current command, resume with fgin the foreground or bg in the background. | |
| Ctrl+D | log out of current session, similar to exit | |
| Ctrl+W | erases one word in the current line | |
| Ctrl+U | erases the whole line | |
| Ctrl+R | brings up a recent command | |
| exit | log out of current session | |
| !! | repeats the last command | |
| alias | Allows you to substitute a new name for a command | alias help=man, alias long=ls -al |
| alias dir ‘/bin/ls -al \!* | more;’ | ||
| & | Run in background | nice ./a.out& |
| > | Redirect to file | nice ./a.out>results.out& |
| >> | Append to file | nice ./a.out>>more.out& |
| < | Input from file | nice ./a.out< input.dat >results.out& |
| | | Pipe to another program | cat *.dat| more |
| ; | Separates commands | ./a.out< input1.dat ; /a.out< input2.dat ; ls |
| $ | Define variable set | echco $variablename |
| * ? | Wildcard characters | ls *.tex ; lsa* ; ls *.???; lsfile?.txt |
| !! $! | Last command, last word | echo “!!” |
| ~/.cshrc | Initialization file | Define shell variables and aliases |
| ~/.login | Initialization file | Set 1-time login information |
| ~/.ssh/known_hosts | ssh keys file | Keys accepted from other hosts; sometimes needs editing. |
| © 2012 Md. Khurshed Alam Nayeem | |
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