How to echo a list on seperate lines in unix

veryangryman

Hi - i have a variable (lets just call it $list) and want to output it line by line to a file. Does echo provide such a facility directly or do we need a for loop

boblong

I'm sure there is some awesome way using just echo and I hope someone else posts their insight.

Presuming $list is an array, here's what I would do:

#!/bin/bash

arr=(hello world something etc)
echo ${arr[@]} | tr ' ' '\n' > file.txt

This is probably quite the hack, but there it is

ocallagh

edit: misread OP

Procasinator

boblong wrote: »

I'm sure there is some awesome way using just echo and I hope someone else posts their insight.

Presuming $list is an array, here's what I would do:

#!/bin/bash

arr=(hello world something etc)
echo ${arr[@]} | tr ' ' '\n' > file.txt

This is probably quite the hack, but there it is

Won't work for strings with spaces in them, like:

arr=('hello world' 'something' 'etc')

As hello world would be split.

One solution would be to replace all the spaces in the strings with a character you know won't be in the input (in this example, _), and tr them back to spaces.

echo ${arr[@]// /_} | tr '_ ' ' \n'

However OP, I believe your best best is to use a for loop on ${list[@]}.

backboiler

veryangryman wrote: »

Hi - i have a variable (lets just call it $list) and want to output it line by line to a file. Does echo provide such a facility directly or do we need a for loop

Does the input arrive line-by-line?
Have you seen the difference between

echo $line

and

echo "$line"

(i.e. with double quotes). The latter may do what you want if the input is formatted that way since it stops the shell interpreting whitespace sequences (it converts them to a single space).