shell option for execFileSync , the parameters cannot be obtained in the script

I'm not sure if it's a bug or whether it's the design intent.

Version: v10.15.2
Platform: Darwin bogon 18.7.0 Darwin Kernel Version 18.7.0 x86_64
Subsystem:

bin/test.sh

#!/bin/bash

echo $1
echo $2

here is my debug info:

node/lib/child_process.js

Line 601 in 1a96d83

return child_process.spawnSync(opts);

the final exec script

/bin/sh -c ./bin/test.sh arg0 arg1

here is my trying

the final exec script

/bin/sh -c "./bin/test.sh arg0 arg1"

it's work fine in window 10 + git bash

This command:

child_process.execFileSync('./bin/test.sh', ['arg0', 'arg1'], {shell: true})

Ends up executing this (note the quotes):

/bin/sh -c "/bin/sh -c ./bin/test.sh arg0 arg1"

Which then executes (note the lack of quotes):

/bin/sh -c /bin/sh -c ./bin/test.sh arg0 arg1

-c takes exactly one argument so arg0 and arg1 are effectively discarded here. Therefore, what's ultimately executed is this:

./bin/test.sh

Compare sh -c /bin/echo no bueno, that doesn't print anything either.

If you drop the {shell: true} it works like (I think) you expect it to.

I'm going to close this out because it's not a bug, just (perhaps not completely obvious) shell interaction.

@bnoordhuis

@bnoordhuis

thanks

as you said

Ends up executing this (note the quotes):
/bin/sh -c "/bin/sh -c ./bin/test.sh arg0 arg1"

l tried it too

/bin/sh -c "/bin/sh -c \"./bin/webp.sh arg0 arg1\""

it work fine

thank again

@bnoordhuis

If you drop the {shell: true} it works like (I think) you expect it to.

[...] it's not a bug, just (perhaps not completely obvious) shell interaction.

That statement make some sense to me for {shell: true}, but what about something like {shell: "/bin/bash"} - i.e. if the intend is to use a specific shell (e.g. because a specific shell's feature set is required)?

The provided explanation suggests to me that it is expected that execFileSync cannot be used with both a custom shell and arguments. is that correct, @bnoordhuis?

On a related note, the described problem does not exist with execFile. That discrepancy is unexpected to me.

For reference, I tested this on Ubuntu 20.04.4 LTS with both Node v16.15.0 and Node v18.3.0 using the script:

import { execFile, execFileSync } from "node:child_process";

const stdout = execFileSync(
  "echo",
  ["foo", "bar"],
  { shell: "/bin/bash" },
);
console.log(`execFileSync: ${stdout}`); // Outputs: "execFileSync: \n"

execFile(
  "echo",
  ["foo", "bar"],
  { shell: "/bin/bash" },
  (_, stdout) => {
    console.log(`execFile: ${stdout}`); // Output: "execFile: foo bar\n"
  }
);

@ericcornelissen

@ericcornelissen

The provided explanation suggests to me that it is expected that execFileSync cannot be used with both a custom shell and arguments. is that correct

I can't really answer that with yes or no because it depends on the shell. For Bourne-like shells: yes.

the described problem does not exist with execFile

I think you've spotted a bug. This is args after normalization:

$ env NODE_DEBUG=child_process node t.js 2>&1 | grep -w args
  args: [ '/bin/bash', '-c', '/bin/bash -c echo foo bar' ],
  args: [ '/bin/bash', '-c', 'echo foo bar' ],

Can you open a new issue for that?

I can't really answer that with yes or no because it depends on the shell. For Bourne-like shells: yes.

I see. Rereading everything in this thread following your comment clarified it to me.

Still, I can't help but wonder if that behaviour should be fixed. What if, rather than joining the args if options.shell is truthy:

node/lib/child_process.js

Lines 564 to 565 in b631086

    
           if (options.shell) { 
        
             const command = ArrayPrototypeJoin([file, ...args], ' ');

we pass the individual args to spawn. So, oversimplified, do:

function execFileSync(file, args, options) {
  spawnSync('/bin/bash', ['-c', file, ...args], options);
}

Am I missing something or would that make sense?

Can you open a new issue for that?

Done 🙂

@ericcornelissen

@ericcornelissen - Can you reference the new issue you opened for this problem? I just ran into this problem today and think this behavior is bizarre and should be fixed. But I don't know what the 'new' issue that is tracking this problem.

@davewichers

@davewichers it's #43333 (there's a reference to it just above my previous comment).

The problem has been fixed for me since v18.7.0 - I don't know if the fix got backported to older LTS releases.

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shell option for execFileSync , the parameters cannot be obtained in the script #29466

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	if (options.shell) {
	const command = ArrayPrototypeJoin([file, ...args], ' ');

shell option for execFileSync , the parameters cannot be obtained in the script #29466

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rambo-panda commented on Sep 6, 2019

bnoordhuis commented on Sep 6, 2019

rambo-panda commented on Sep 6, 2019

ericcornelissen commented on Jun 5, 2022

bnoordhuis commented on Jun 6, 2022

ericcornelissen commented on Jun 6, 2022

davewichers commented on Nov 22, 2022

ericcornelissen commented on Nov 22, 2022

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