While loop in bash using variable from txt file

Question

I am new to bash and writing a script to read variables that is stored on each line of a text file (there are thousands of these variables). So I tried to write a script that would read the lines and automatically output the solution to the screen and save into another text file.

./reader.sh > solution.text

The problem I encounter is currently I have only 1 variable store in the Sheetone.txt for testing purpose which should take about 2 seconds to output everything but it is stuck in the while loop as well as is not outputting the solution.

#!/bin/bash
file=Sheetone.txt
while IFS= read -r line
do
        echo sh /usr/local/test/bin/test -ID $line -I 
done

Your while read does not have any input, you may want to say do ... done < file so that it is fed by the content of file. — fedorqui
– fedorqui, Commented Jun 22, 2015 at 14:43

fedorqui · Accepted Answer · 2015-06-22 14:54:18Z

2

As indicated in the comments, you need to provide "something" to your while loop. The while construct is written in a way that will execute with a condition; if a file is given, it will proceed until the read exhausts.

#!/bin/bash
file=Sheetone.txt
while IFS= read -r line
do
    echo sh /usr/local/test/bin/test -ID $line -I 
done < "$file"
# -----^^^^^^^ a file!

Otherwise, it was like cycling without wheels...

answered Jun 22, 2015 at 14:54

fedorqui

293k113 gold badges592 silver badges640 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

While loop in bash using variable from txt file

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related