input_file1:
text1
text2
text3

input_file2:
#some stuff and more text
#this is the second line...

and this is what I want to end up with:

text1.txt:
#this file was autogenerated for text1 using input_file2.
#some stuff and more text
#this is the second line...
input:text1 input:text2 input:text3

text2.txt:
#this file was autogenerated for text2 using input_file2.
#some stuff and more text
#this is the second line...
input:text1 input:text2 input:text3

text3.txt:
#this file was autogenerated for text3 using input_file2.
#some stuff and more text
#this is the second line...
input:text1 input:text2 input:text3