[SOLVED] Grep ignoring/not catching first line of file

Issue

I am trying to do a script that read all lines of a file and grep a line if contains the expecify word in the grep (in this case the word is apple), but I am having a issue that the grep is ignoring/not catching the first line of the file.

Here is my script:

#!/bin/bash

while read line;
do
    grep 'apple' > fruits2.txt
    
done < fruits.txt

The input file "fruits.txt"

apple 1
banana
apple 2
grape
orange
apple 3
blueberry
apple 4

The output file "fruits2.txt"

apple 2
apple 3
apple 4

Solution

So you are creating a loop, in order to read an entire file line by line, and let grep verify if there is something inside that line.

You are correct that grep can read just a single line.

But: grep can read an entire file, that's what is has been created for.

So, you don't need to create your own loop, you can just do:

grep "apple" fruits.txt

The result will be:

apple 1
apple 2
apple 3
apple 4

As an extra: imagine that you add "pineapple 666" to your "fruits.txt" file, then you will see this one too in your output. In case you don't want that:

grep -w "apple" fruits.txt

(the -w says that only entire words may be shown.)

Answered By - Dominique

Answer Checked By - Cary Denson (WPSolving Admin)