Bash: Inserting one file's content into another file after the pattern

Question

I\'m trying to write a bash script, which will do the following:

1. reads the content from the first file (as a first argument)
2. reads the content from th

Answer 1

This should work:

perl -lne 'BEGIN{open(A,"first_file.txt");@f=;}print;if(/2222/){print @f}' second_file.txt

Tested:

> cat temp
111111
1111
11
1
> cat temp2
122221
2222
22
2
> perl -lne 'BEGIN{open(A,"temp");@f=;}print;if(/2222/){print @f}' temp2
122221
111111
1111
11
1

2222
111111
1111
11
1

22
2
>