Question

I have a file with contents

abc dbw ;\
xxx{ sample test } 
bewolf \
bewolf 
test

I need to check for

 xxx{ sample test }
 bewolf

and comment out these line like

/*xxx{ sample test }
bewolf*/

I have tried with grep but grep searches for string. As Dash script does not have arrays it makes it an even tougher job.

I was trying to get the starting and end index so that I can cut out that section using head and tail.

Any other ideas like using sed and awk are welcomed.

To be more general, I need to comment one macro in a C file using a Bash script.

Answer 1

If multiple end comments don’t bother you, you could use a simple sed like this:

sed -e "s%^xxx{ sample test }$%\/\*&\*\/%" -e "s%^bewolf$%\/\*&\*\/%" file.txt

input:

abc dbw ;\
xxx{ sample test }
bewolf \
bewolf
test

output:

abc dbw ;\
/*xxx{ sample test }*/
bewolf \
/*bewolf*/
test

Add the -i flag if you would like to overwrite file.txt directly.