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

sed can do that without loops. Use its r command:

sed -e '/pattern/rFILE1' FILE2

Test session:

$ cd -- "$(mktemp -d)" 
$ printf '%s\n' 'nuts' 'bolts' > first_file.txt
$ printf '%s\n' 'foo' 'bar' 'baz' > second_file.txt
$ sed -e '/bar/r./first_file.txt' second_file.txt
foo
bar
nuts
bolts
baz