Question

for documentation need i have a shell scripts, where i have to add certain string at the start and end in the shell scripts in a given line, the line number is random and contain in the list

for example :-  
test.sh 
line number := 2,5,6,7,9
Add "&gt" "/&gt"

in test.sh file go to the line number 2 and add "&gt" in the start of the line and "/&gt" at the end of the line do the same for line number 5,6,7,9

Answer 1

sed -i~ '2{s/^.*$/"\&gt"&"\\\&gt"/}' FILE

Here 2 is line number. "\&gt" and "\\\&gt" are prefix and suffix respectively(You need to escape & and \). You will have a backup file suffixed with ~.