Passing parameters to bash when executing a script fetched by curl

Question

I know how to execute remote Bash scripts like this:

curl http://example.com/script.sh | bash

or

bash < <( curl http://example.com/script.sh )

which give the same result.

But what if I need to pass arguments to the bash script? It's possible when the script is saved locally:

./script.sh argument1 argument2

I tried several possibilities like this one, without success:

bash < <( curl http://example.com/script.sh ) argument1 argument2

score 144 · Answer 1 · answered Aug 29 '14 at 07:11

144

To improve on jinowolski's answer a bit, you should use:

curl http://example.com/script.sh | bash -s -- arg1 arg2

Notice the two dashes (--) which are telling bash to not process anything following it as arguments to bash.

This way it will work with any kind of arguments, e.g.:

curl -L http://bootstrap.saltstack.org | bash -s -- -M -N stable

This will of course work with any kind of input via stdin, not just curl, so you can confirm that it works with simple BASH script input via echo:

echo 'i=1; for a in $@; do echo "$i = $a"; i=$((i+1)); done' | \
bash -s -- -a1 -a2 -a3 --long some_text

Will give you the output

1 = -a1
2 = -a2
3 = -a3
4 = --long
5 = some_text

answered Aug 29 '14 at 07:11

Janne Enberg

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An excellent suggestion, and very clear as to the reason why you should do this. – shrikeh Sep 12 '14 at 13:36
Thanks for the clear explanation. This trick is really useful! – agate Jul 19 '16 at 07:03
3

for extra safety, it's advisable to use `curl --fail ...`. It makes curl stop on a 404, for example. A common set of options is `-fsSL` (`-f` is the short version of `--fail`). – jpbochi Jul 03 '18 at 13:04
what if the command fail with because it asks a yes or no question? – Freedo Jun 04 '19 at 03:59
Thanks! This is the only solution that worked for me, ie `curl -fsSL https://starship.rs/install.sh | bash -s -- --yes`. – Daniel Kim Mar 04 '21 at 16:05

score 101 · Accepted Answer · answered Jan 10 '11 at 01:19

101

try

curl http://foo.com/script.sh | bash -s arg1 arg2

bash manual says:

If the -s option is present, or if no arguments remain after option processing, then commands are read from the standard input. This option allows the positional parameters to be set when invoking an interactive shell.

answered Jan 10 '11 at 01:19

jinowolski

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Thanks ! Extremely useful with gists :) – Daniel R Jan 10 '11 at 01:37
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What about parameters that use keys like `-p blah -d blah`? – CMCDragonkai May 15 '14 at 06:21
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The `read` in script is directly ignored by this way, how to fix this? – hwding Oct 16 '17 at 02:13
@hwding My answer below features that https://stackoverflow.com/a/72207423/4374258 – Sohail Si May 12 '22 at 09:22

score 21 · Answer 3 · answered Jan 10 '11 at 01:20

21

Other alternatives:

curl http://foo.com/script.sh | bash /dev/stdin arguments
bash <( curl http://foo.com/script.sh ) arguments

answered Jan 10 '11 at 01:20

ephemient

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All methods differ on $0 argument. For "-s" it's "bash", for "/dev/stdin" it's "/dev/stdin" and "<(...)" gives $0 argument like "/dev/fd/63". – jinowolski Jan 10 '11 at 01:32
First alternative works with script arguments beginning with a `-`, i.e. options – Antonio Pérez Sep 20 '13 at 21:34
Please give an example for a argument to let me know the format – Grim Jan 22 '17 at 10:54

Sohail Si · Answer 4 · 2022-05-11T20:58:00.813

Building on others' answers, if you want your bash script to use pipes, try:

cat myfile.txt | \
bash -c "$(curl http://example.com/script.sh )" -s arg1 arg2

Example usage:

#!/usr/bin/env bash

export MYURL="https://raw.githubusercontent.com/sohale/snippets/master/bash-magic/add-date.sh"
curl http://www.google.com | \
bash -c "$(curl -L $MYURL )" -s "       >>>>> next line "

If you use bit.ly to shorten the url, don't forget the -L.

Passing parameters to bash when executing a script fetched by curl

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