UNIX for Dummies Questions & Answers

Using the bash shell I am trying to read in 2 files. The first file (file1) is a list of names to search for in (file2). If a name in file1 is found in file2 I want the entire line in file2 to be printed to an output file. File1 consists of a single column of names. File2 consists of several columns of data.

I have been having problems:
1) Reading a File1 into an array
2) Searching for each element in the array in File2
3) Printing the line in File2 on which the element from File1 was found

Here is the script I have so far:

#!/bin/bash

echo "Please enter the file of names to be searched for"

read file1

echo "Please enter the lookup table file"

read file2

for g in $file1
do
grep $g file2
done

Any help would be greatly appreciated.

Thanks, Lanna

Many/most? greps have a -f switch for accepting patterns from a file. If your grep has -f, then just do:

Code:

grep -f file1 file2

No array or for loop and stuff needed then.

Thanks for the reply. That did make things easier however it's not behaving exactly as I'd like.

grep -f file1 file2

This finds every occurrence of the line in file1 in file2. So, I would expect the output to have the same number of lines as file1. However, the output has the same number of lines as file2. Why is it matching a blank line pattern in file1 to lines in file2?

To make his more clear, there are 46 lines in file1 and 51 lines in file2. I expect the output to have 46 lines, one line for every match from file1 found in file2. Instead, the output has 51 lines.

What is going wrong?

Thanks, Lanna