Unix / Linux Commands
Posted by admin on 8 July, 2009
1 comment so far
This item was filled under [ Linux ]
File Commands
| ls | directory listing |
| ls -al | formatted listing with hidden files |
| cd dir | change directory to dir |
| cd | change to home |
| pwd | show current directory |
| mkdir dir | create a directory dir |
| rm file | delete file |
| rm -r dir | delete directory dir |
| rm -f file | force remove file |
| rm -rf dir | force remove directory dir |
| cp file1 file2 | copy file1 to file2 |
| cp -r dir1 dir2 | copy dir1 to dir2; create dir2 if it doesn’t exist |
| mv file1 file2 | rename or move file1 to file2 if file2 is an existing directory, moves file1 into directory file2 |
| ln -s file link | create symbolic link link to file |
| touch file | create or update file |
| cat > file | places standard input into file |
| more file | output the contents of file |
| head file | output the first 10 lines of file |
| tail file | output the last 10 lines of file |
| tail -f file | output the contents of file as it grows, starting with the last 10 lines |
Process Management
| ps | display your currently active processes |
| top | display all running processes |
| kill pid | kill process id pid |
| killall proc | kill all processes named proc * |
| bg | lists stopped or background jobs; resume a stopped job in the background |
| fg | brings the most recent job to foreground |
| fg n | brings job n to the foreground |
File Permissions
| chmod 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 all |
| chmod 755 | rwx for owner, rx for group and world |
SSH
| ssh user@host | connect to host as user |
| ssh -p port user@host | connect to host on port port as user |
| ssh-copy-id user@host | add your key to host for user to enable a keyed or passwordless login |
Searching
| grep pattern files | search for pattern in files |
| grep -r pattern dir | search recursively for pattern in dir |
| command | grep pattern | search for pattern in the output of command |
| locate file | find all instances of file |
System Info
| date | show the current date and time |
| cal | show this month’s calendar |
| uptime | show current uptime |
| w | display who is online |
| whoami | who you are logged in as |
| finger user | display information about user |
| uname -a | show kernel information |
| cat /proc/cpuinfo | cpu information |
| cat /proc/meminfo | memory information |
| man command | show the manual for command |
| df | show disk usage |
| du | show directory space usage |
| free | show memory and swap usage |
| whereis app | show possible locations of app |
| which app | show which app will be run by default |
Compression
| date | show the current date and time |
| tar cf file.tar files | create a tar named file.tar containing files |
| tar xf file.tar | extract the files from file.tar |
| tar czf file.tar.gz files | create a tar with Gzip compression |
| tar xzf file.tar.gz | extract a tar using Gzip |
| tar cjf file.tar.bz2 | create a tar with Bzip2 compression |
| tar xjf file.tar.bz2 | extract a tar using Bzip2 |
| gzip file | compresses file and renames it to file.gz |
| gzip -d file.gz | decompresses file.gz back to file |
Network
| ping host | ping host and output results |
| whois domain | get whois information for domain |
| dig domain | get DNS information for domain |
| dig -x host | reverse lookup host |
| wget file | download file |
| wget -c file | continue a stopped download |
Installation
| ping host | ping host and output results |
| Install from source: |
./configure make make install |
| dpkg -i pkg.deb | install a package (Debian) |
| rpm -Uvh pkg.rpm | install a package (RPM) |
Shortcuts
| Ctrl+C | halts the current command |
| Ctrl+Z | stops the current command, resume with fg in 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 | type to bring up a recent command |
| !! | repeats the last command |
| exit | log out of current session |
Popularity: 31 views
