Sunday, July 24, 2011

Basic Linux command for beginner

 File Commands:
1.    ls   -– directory listing (to see the content of folder)
2.    ls -al   -– formatted listing with hidden files
3.    cd dir  -– change directory to dir
4.    cd  -– change to home
5.    pwd  -– show current directory
6.    mkdir dir  -– create a directory dir
7.    rm file   -– delete file
8.    rm -r dir  -– delete directory dir
9.    rm -f dir  -– force remove file
10.  rm -rf dir  -– force remove directory dir
11.  cp file1 file2  -– copy file1 to file2
12.  cp -r dir1 dir2  -– copy dir1 to dir2; create dir2 if it doesn't exist
13.  mv file1 file2  –- rename or move file1 to file2
                                 if file2 is an existing directory, moves file1 into directory file2
14.   ln -s file link  –- create symbolic link link to file
15.   touch file  –- create or update file
16.   cat > file  -– places standard input into file
17.   more file  –- output the contents of file
18.   head file  –- output the first 10 lines of file
19.   tail file  –- output the last 10 lines of file
20.   tail -f file  -– output the contents of file as it

SEARCHING :
1.    grep pattern files  -– search for pattern in files
2.    grep -r pattern dir  -– search recursively for pattern in dir
3.    command | grep pattern  -– search for pattern in the output of command
4.    locate file  –- find all instances of file

NETWORK :
1.    ping host  –- ping host and output results
2.    whois domain  -– get who is information for domain
3.    dig domain  –- get DNS information for domain
4.    dig -x host  -– reverse lookup host
5.    wget file  –- download file
6.    wget -c file  -– continue a stopped download

SHORTCUTS :
1.    ctrl+c  –- halt the current command
2.    ctrl+z  –- stops the current command ,resume with fg in the foreground or bg
                         in the background.
3.    ctrl+d  –- logout of current session, similar to exit
4.    ctrl+w  –- erases one word in the current line
5.    ctrl+u  –- erases the whole line
6.    ctrl+r  –- type to bring up a recent command
7.    !!  –- repeats the last command
8.    exit  –- log out of current session

PROCESS MANAGEMENT :
1.    ps  –- display your currently active processes
2.    top  -– display all running processes
3.    killpid  -– kill process id pid
4.    killall proc  -– kill all processes named proc (use with extreme caution)
5.    bg  –- lists stopped or background jobs; resume a stopped job in the background
6.    fg  –- brings the most recent job to foreground
7.    fg n  -– brings job n to the foreground

SYSTEM INFO :
1.    date  -– show the current date and time
2.    cal  –- show this month's calendar
3.    uptime  –- show current uptime
4.    w  –- display who is online
5.    whoami  -– who you are logged in as
6.    finger user  -– display information about user
7.    uname -a  –- show kernel information
8.    cat /proc/cpuinfo  –- cpu information
9.    cat /proc/meminfo  -– memory information
10.  man command  -– show the manual for command
11.  df  –- show disk usage
12.  du –- show directory space usage
13.  free  -– show memory and swap usage
14.  whereis app  -– show possible location of app
15.  which app  –- show which app will bw run by default.

COMPRESSION :
1.    tar cf file.tar files  –- create a tar named file.tar containing files
2.    tar xf file.tar  –- extract the files from file.tar
3.    tar czf file.tar.gz files  -– create a tar with Gzip compression
4.    tar xzf file.tar.gz  –- extract a tar using Gzip
5.    tar cjf file.tar.bz2  –- create a tar with Bzip2
6.    gzip file  –- compresses file and renames it to file.gz
7.    gzip -d file.gz  –- decompresses file.gz back to file.
Remember Linux is case-sensitive.


For better understand see video:
basic linux command part 1