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Keeran
Asked: 2023-02-10 13:36:40 +0800 CST

how to execute a string block from a file

  • 772

I have the following command saved in mat.txt file:

printf "
       _       ____            __ _
 _ __ (_)_  __/ ___|_ __ __ _ / _| |_
| '_ \| \ \/ / |   | '__/ _` | |_| __|
| | | | |>  <| |___| | | (_| |  _| |_
|_| |_|_/_/\_\\____|_|  \__,_|_|  \__|


"

when I execute this file after made it executable using:

chmod +x mat.txt

It gives me an Error:

enter image description here

It's saying like command not found, file end reached when searching for ' & syntaxerror.

Anyone knows why?

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2 Answers

  1. Best Answer

    From man bash:

    Enclosing characters in double quotes preserves the literal value of all characters within the quotes, with the exception of $, `, , and, when history expansion is enabled, !.

    In other words, " ... " is not sufficient to protect the unbalanced backtick on line 4 of your text; the shell is interpreting it as the start of a command substitution.

    OTOH you can't use single quotes, because your text contains single quotes.

    I'd suggest avoiding the issue of quoting altogether by using a here document. You should also use a shebang to make sure your file is interpreted by the intended shell. So:

    #!/bin/sh

cat <<'TXT'
       _       ____            __ _
 _ __ (_)_  __/ ___|_ __ __ _ / _| |_
| '_ \| \ \/ / |   | '__/ _` | |_| __|
| | | | |>  <| |___| | | (_| |  _| |_
|_| |_|_/_/\_\\____|_|  \__,_|_|  \__|


TXT

    then

    $ ./mat.txt
       _       ____            __ _
 _ __ (_)_  __/ ___|_ __ __ _ / _| |_
| '_ \| \ \/ / |   | '__/ _` | |_| __|
| | | | |>  <| |___| | | (_| |  _| |_
|_| |_|_/_/\_\\____|_|  \__,_|_|  \__|
    • 5

  2. You didn't ask for a specific interpreter in your question. Therefore, Python(which allows assigning a multi-line string to a variable using triple quotes be it single ''' ... ''' or double """ ... """) might be an option like so:

    #!/bin/python3

a = '''
       _       ____            __ _
 _ __ (_)_  __/ ___|_ __ __ _ / _| |_
| '_ \| \ \/ / |   | '__/ _` | |_| __|
| | | | |>  <| |___| | | (_| |  _| |_
|_| |_|_/_/\_\\____|_|  \__,_|_|  \__|
'''

print(a)

    Which executes like so:

    $ ./mat.txt 

       _       ____            __ _
 _ __ (_)_  __/ ___|_ __ __ _ / _| |_
| '_ \| \ \/ / |   | '__/ _` | |_| __|
| | | | |>  <| |___| | | (_| |  _| |_
|_| |_|_/_/\_\____|_|  \__,_|_|  \__|
    • 0