A shell script is a computer program designed to be run by the Unix shell, a command-line interpreter. The various dialects of shell scripts are considered to be scripting languages. Typical operations performed by shell scripts include file manipulation, program execution, and printing text. A script that sets up the environment, runs the program, and does any necessary cleanup, logging, etc. is called a wrapper.
In this post, we will write a shell script to cut n lines starting with position m from a file without using head or tail commands.
line 1: filename
line 2: number of lines (n)
line 3: starting position (m)
The following is the shell script to cut n lines starting with position m without using head or tail commands:
echo enter fiename read file echo enter no of line read n echo enter starting position read m t=$(expr $n + $m) e=1 exec < $file while read line do if [ $e -ge $m -a $e -lt $t ] then echo $line fi e=$(expr $e + 1) done
$ enter fiename $ a $ enter no of line $ 3 $ enter starting position $ 2 $ line 2 $ line 3 $ line 4
Let us know in the comments if you are having any questions regarding this shell script.
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