The following table is a list of most frequently used commands in Linux/Unix.Table gives commands with the description on usage.
you can try below commands in web page based online Linux Terminal.
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Command
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Command description
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pwd
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prints working directory
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who I am
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prints user name
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which shell/Perl
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shows version or type of shell/Perl
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alias c clear
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to create alias
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> file1
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direct to file1,
ex: cat temp1 > file1
cat the file temp1 and creates file1,directs to it
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>> file1
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append to file1, ex: cat temp1 > >file1
cat the file temp1 and directs to existing file file1 and appends it,
if the file is not existing it creates and directs to it
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sort file.txt
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sort the file
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sort -r file.txt
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sort the file in descending order
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cd –
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toggle between two directories
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tail file.txt
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prints last 10 lines of file.txt
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tail –n N file.txt
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prints last N number of lines of file.txt
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less big.log
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Displays less contents of big file.
Ctrl+F Forward to next window
Ctrl+B Backward to one window
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cp -pi file1 file2
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copy file1 to file2
-p preserves Mode, Time stamp and Ownership Information
-i ask for confirmation before copying
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rm -irf folder/*
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remove folder,
-i ask for confirmation before copying
-r remove recursively
-f forcefully
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chmod ug+rwx file1
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give read, write and execute permission to file1
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chmod g-rwx file1
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revoke read, write and execute permission to file1
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chmod –R ug+rwx folder/*
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give read, write and execute permission to files recursively
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diff folder1 folder2
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difference between folder1 and folder2
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gvimdiff file1 file2
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diff the two files and show the result in gvim window
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grep –ir “pattern” *
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grep for pattern in all the files ,
-i insensitive
-r recursive
-w complete word
-A <N> prints matched lines and +N lines after matched line
-C <N> prints N lines around matches line
-v displays Invert match
-c Counts number of occurrence
-l displays only files name
-o shows only matched string
-n shows line number along with matched line
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find . –name “filename.log”
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finds for filename.log
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find ~ -name “filename.log”
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finds for filename.log in home directory
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gzip file.txt
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to create gzip,file.txt.gz
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gzip –d file.txt.gz
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to uncompress file.txt.gz and makes file.txt
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tar cvf archive_name.tar directory_name/
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creates new tar
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tar xvf archive_name.tar
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extracts from existing tar
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tar tvf archive_name.tar
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view an existing tar
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su user_name
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switch user to user_name
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bjobs
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list the ongoing jobs with job id
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bkill <job_id>
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kill <job_id> process
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bqueues
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list the available queues and queue details
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du –sh folder1
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check disk usage of folder1
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find -type f \( -name ‘*.swp’ -o -name ‘*~’ -o -name ‘*.bak’ -o -name ‘.netrwhist’ \) -delete
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to delete swap files
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ln s hello.txt s_link
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Creates a symbolic link named s_link that points to the file hello.txt
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free
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Displays the amount of used and free system memory
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whoami
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prints the user id
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df h
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report file system disk space usage
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du h
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disk usage of each file, recursively for directories
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ps aux
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ps (process status) command is used to provide information about currently running processes with process identification numbers
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sed commands:
sed editor for filtering and transforming text.
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sed i ‘1,10d’ hello.txt
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deleted the first 10 lines from hello.txt
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sed i ‘‘2’i hai’ hello.txt
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Inserts the text ‘hai’ in the second line
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sed i ‘/hello/d’ hello.txt
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Deleted the line containing the pattern hello.
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sed ‘s/hello/world/’ hello.txt
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Replaces the first occurrence of hello on each line to world
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sed ‘s/hello/world/g’ hello.txt
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Replaces all the occurrences of hello on each line to world.
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.cshrc file
awk commands