bash loop through list of strings

Question

Is it possible to format this sample:

for i in string1 string2 stringN
do
 echo $i
done

to something similar to this:

for i in 
string1
string2
stringN
do
 echo $i
done

EDIT: Sorry for confusion, didn't realize that there was different methods of executing script - sh <scriptname> versus bash <scriptname> and also this thing which I cannot name right now - #!/bin/sh and #!/bin/bash :)

Solution 1

Using arrays in bash can aid readability: this array syntax allows arbitrary whitespace between words.

strings=(
    string1
    string2
    "string with spaces"
    stringN
)
for i in "${strings[@]}"; do
    echo "$i"
done

Solution 2

You can escape the linebreak with a backslash:

$ for i in \
> hello \
> world
> do
> echo $i
> done
hello
world
$

Solution 3

You may escape the newlines before/after each item that you loop over:

for i in \
    string1 \
    string2 \
    stringN
do
   printf '%s\n' "$i"
done

Or, for this simple example:

printf '%s\n' string1 string2 stringN

which has the same result.

Related:

• Why do I need to place “do” in the same line as “for”?

Variation using a bash array:

strings=(
    string1
    string2
    stringN
)
printf '%s\n' "${strings[@]}"

Solution 4

list='a b c d'
for element in $list;do 
    echo "$element"
done

Solution 5

If switching to zsh is an option:

for string (
  string1
  'other string'
  etc..
) printf '%s\n' "$string"

View more solutions

Comments

[jesse_b]

What is the problem you are trying to solve?

[Pankaj Goyal]

Did you try what you're asking to see whether it'd work?

[Admin]

@Jesse_b readability and managebility of bunch of strings

[Admin]

@DopeGhoti yes I did

[jesse_b]

@waayee: In that case an array is your best bet. See Glenn Jackman's answer.

[Admin]

This seems most elegant, but unfortunately gives error: Syntax error: "(" unexpected

[ilkkachu]

@waayee, then you're not running it in Bash. Remember that sh isn't necessarily Bash, and especially isn't on Debian and Ubuntu.

[Admin]

@ilkkachu Think I get it now - must run "bash <scriptname>" not "sh <scriptname>" :)

[rrrrr]

@glennjackman: what does the @ do? If I wanted "${strings[@]}" to be separated by commas instead of spaces, is it easy to do that?

[Angel Todorov]

@rrrrr, your questions are probably answered here: stackoverflow.com/q/12314451/7552

[Dims]

Syntax error "( unexpected"

[Angel Todorov]

Read the other comments - that error has already been discussed.

[41754]

You are missing semicolons!

[Kusalananda]

Note that this would work as long as each string is a separate word. As soon as you have spaces in your strings, the spaces would break the string apart into multiple words. Also, if the $list string contains filename globbing characters (list='* * * *'), the shell would potentially replace these with matching filenames.

[Stephen Kitt]

string1 etc. aren’t the literal values to be displayed, they’re placeholders, so this approach doesn’t work.