here-document with bash -c

Mario Palumbo

12/16/23, 7:01 PM

This example script:

cat <<- EOF | bash -c
    command1 args
    command2 args
    command3 args
    command4 args
    command5 args
EOF

Returns: bash: -c: option requires an argument
How do I use bash -c with here-document?

140

1 + 0

bash

22.04

Score:4

Ubuntu

Martin Thornton

12/16/23, 7:58 PM

You don't!

The -c is only for a script passed in as the first argument, not piped in via standard input as a heredoc does.

Instead you use -s, which can be omitted if there are no other arguments passed to the script.

Also, after replacing with -s you could also simplify:

cat <<- EOF | bash -s

to:

<<- EOF bash -s

Like most cats, the cat does nothing.

+ 3

vidarlo

12/16/23, 8:16 PM

+1 for that last sentence :D

Mario Palumbo

12/16/23, 9:50 PM

Is the more correct and elegant syntax `bash -s <<- EOF` or `<<- EOF bash -s`?

Martin Thornton

12/16/23, 10:04 PM

Either is fine. I personally prefer putting `<` and `<<` before the command as it keeps the pipeline in order from left to right, though this is less common.

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: here-document with bash -c

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