script to delete the lines from a file having patterns present in another file

Let us assume we have set of patterns in a file as shown below.

data1:

abcf efgh

And a file with the contents

data2:

1234 : A line of numbers abcf : A line of characters efgh : A line of characters 4567 : A line of numbers

If we want to search for the patterns in the file data1 and delete the lines that have the pattern in the file data2, we can do it using the following script.

del_pattern.sh :

#!/bin/bash while read line do sed -i "/$line/ s/^.*$//" data2 done < data1

save it in the same directory where the above two text files are saved,give it execute permission and execute it.

$ chmod 777 del_pattern.sh $ ./del_pattern $ cat data2 1234 : A line of numbers 4567 : A line of numbers

The while loop, loops through the file data1, reading on line at a time. The sed command in the while loop searches for the pattern in the file data2 and any line that has the pattern will be substituted by a blank line.

Instead of replacing with a blank line, we can delete the line using the following script.

del_pattern.sh

#!/bin/bash while read line do sed -i "/$line/d" data2 done < data1

save it in the same directory where the above two text files are saved,give it execute permission and execute it.

$ chmod 777 del_pattern.sh $ ./del_pattern $ cat data2 1234 : A line of numbers 4567 : A line of numbers