Linux Shell Scripts and Shell Commands✌️

Linux Shell Scripts and Shell Commands✌️

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  Shell Commands and Shell Scripts PresentedBy: Nazmul Hyder ID- 011 131 085
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  Shell Command Identity andManual Command Description $uame Linux will tell you his name to you $whoami If you want to know your name $man uname For each command manual
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  Continue.. Editors Command Description $ kwriteFile write $gedit File Edit $vi
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  Continue.. File Listing Command Description $ls-a Do not hide entries starting with. $ls -h Print size in human readable format $ls -l Use a long listing format $ls -s Sort by file size
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  Continue.. Directory Operations Command Description $pwdIf u want to see your current directory $cd “directory name” To change the directory $mkdir “directory name” Create a new directory $rmdir “directory name” Remove an empty directory $rmdir -r “directory name” Remove directory with file
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  Continue.. File Operations Command Description $cp“file” “copyfile.txt” Copy file $rm “file.txt” To remove file $mv “file.txt “ “directory name” Create a new directory $file -i “file name” To know the file type $file -v “file name” Print the version of the file $cat “file1” “file2” To concat files and print on the standard output
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  Continue.. File Viewing Command Description $echo“some text” You can a line of text in the shell $more file.txt It uses for the Spacebar and the B key for the forward and backward navigation $less “file.txt” Less allows forward and backward movement using arrow keys $head filename To see the first 10 contents of the file $tail filename To see the last 10 contents of the file
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  Continue.. File Viewing Command Description $filename-n To print the line number of the file $sort file1 file2 To write the sorted concatenation of all the file and standard output $wc filename Print bytes,words,total lines $wc -l or -w You can see specific
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  Continue.. Piping and Grep CommandDescription $head -10 a.txt | tail -5 To see 5-10 number lines of a file $grep “a” file.txt Print lines which contains “a” $grep -i For case insensitive search $grep -c Count total matches $grep -n Display the line number of matches
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  Continue.. Grep Command Description $grep -E[^F] filename Anything except capital F $grep -E [$a] filename Anything that ends with a $grep -E [a-zA-Z] filename Anything that contains small a to z and capital A to Z
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  Shell Script Advantage ofshell script : ● It take input from user , file and output them on screen. ● Useful to create own commands. ● Save time.
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  Continue.. Write and Execute: ● We can use any editor to write the shell script. ● The extension is .sh ● Two thing you can need to do before execute file ○ Chmod +x script_name “set execute permission for your script” ○ ./script_name “execute script”
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  Continue.. Shell Script Examples Arithmeticif-else Case #!/bin/bash expr 1 + 1 expr 1 ‐1 expr 1 * 1 expr 1 / 1 var=`expr 1 + 1` x=1 x=`expr $x + 1` #!/bin/bash echo "Enter first number " read num1 echo "Enter second number" read num2 if [ $num1 ‐gt $num2 ] ; then echo "$num1 is greater than $num2" elif [ $num1 ‐lt $num2 ] ; then echo "$num1 is less than $num2" else echo "$num1 and $num2 are equal" fi #!/bin/sh echo “Is it morning? Please answer yes or no” read timeofday case “$timeofday” in yes) echo “Good Morning”;; no ) echo “Good Afternoon”;; y ) echo “Good Morning”;; n ) echo “Good Afternoon”;; * ) echo “Sorry, answer not recognized”;; esac
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  Thank You