#!/bin/bash
while read file1 <&3; do
while read file2 ; do
if [ $file1 == $file2 ] ; then
$file1 >> /infanass/dev/admin/test/newlist.txt
fi
echo "$file1"
echo "$file2"
done 3</infanass/dev/admin/test/file2.txt
done 3</infanass/dev/admin/test/file1.txt
I want to read one line from file1.txt and then loop through file2.txt and see if there is a match and if there is write it out too a new text file..
I think I have a infinite loop..
How about a simpler approach?
while read line do
grep "^$line$" file2.txt >>matches.txt
done < file1.txt
Explanation:
This loops through file1.txt line by line and uses grep to look for the exact line in file2.txt. Now grep will output the line again if it was able to match it in file2.txt and it's then redirected (appended) to the file matches.txt.
The reason your script is stalling is that your second loop is awaiting input on stdin: you forgot to make its stdin a duplicate of file descriptor 3 as you did with the first one. In any case, no extra file descriptors need be created: you can just redirect stdin so that the while loop reads from a file and not the terminal.
Use comm to find the intersection:
comm -12 <(sort file1.txt) <(sort file2.txt) > newlist.txt
comm requires its input files to be sorted.
Why not do it even simpler by feeding file1 as search terms to grep and let it search for it in file2?
$ grep -f file1 file2 > file3
Please note that on some platforms you need/want egrep or ggrep because of performance issues.
