In my file 'foo' there is a first line: 'a b', and the second line: 'c d':
$ cat foo
a b
c d
I want to print in terminal in loop these two lines: one after another:
$ for i in $(cat foo); do echo $i; done
But in the output 'echo' command breaks the order, so instead of having:
a b
c d
I actually have:
a
b
c
d
for i in $(cat foo) does not loop lines but words (or fields) split by your field separator $IFS. It default to (space, newline, tab).
If you change your field separator to newline only, you can use your command as is (Disclaimer: please read below!):
IFS=$'
'
for i in $(cat foo); do echo $i; done
You might want to make a backup of IFS to restore it later:
OLD_IFS="$IFS"
.
.
.
IFS="$OLD_IFS"
Output:
a b
c d
However, this is considered bad practice.
while IFS= read -r line; do ... done < filegrep, sed or awk.Please read Why is using a shell loop to process text considered bad practice?.
