Question

Trying to read a file line by line, but its not working, tried many different ways including below:

$ cat test.sh
#!/bin/bash

echo 'line1
line2
line3
line4
;;' > list.txt

IFS=$'\n'

for line in "$(cat list.txt)"
do
   echo "line=$line"
   echo "----"
done

When I run:

$ ./test.sh
line=line1
line2
line3
line4
;;
----

Answer 1

Because you have used quotes around command substitution, $(), the shell is not performing word splitting on newline (IFS=$'\n') (and pathname expansion), hence the whole content of the file will be taken as a single string (the first line has it), instead of newline separated ones to iterate over.

You need to remove the quotes:

for line in $(cat list.txt)

Although it is not recommended to iterate over lines of a file using for-cat combo, use while-read instead:

while IFS= read -r line; do ...;  done <list.txt

Reading a file line-by-line in bash

1 个答案: