Ytukyg

I want to pass a string parameter to a Bash procedure. This procedure prints the string on console and prints a copy to a file.

In my use case, this file will contain a list of all executed commands in a Bash script that can be used to rerun all instructions in the same order. This is needed if an error occurs and I need to send a reproducer script to an open sourc project on GitHub. It will also copy all used files into a directory for later ZIP file creation.

So, let's talk Bash code:

#! /bin/bash

open() {

    local File=$1

    exec 3<> "$File"

}



close() {

    exec 3>&-

}



procedure1() {

    echo "$1"

    echo "echo "$1"" >&3

}



procedure2() {

    echo "$1" "$2"

    echo "echo "$1" "$2"" >&3

}



procedure3() {

    echo "$@"

    echo "echo "$@"" >&3

}



# ==============================================================================

OUTPUT_FILE="output.sh"



Program_A="foo"

Paramater_A=(

    --spam

    --egg=4

)



Program_B="bar"

Paramater_B=(

    --ham

    --spice=4

)



open $OUTPUT_FILE



echo "$Program_A -a ${Paramater_A[@]}"

echo "$Program_B -b ${Paramater_B[@]}"

echo

procedure1 "$Program_A -a ${Paramater_A[@]}" "$Program_B -b ${Paramater_B[@]}"

procedure2 "$Program_A -a ${Paramater_A[@]}" "$Program_B -b ${Paramater_B[@]}"

procedure3 "$Program_A -a ${Paramater_A[@]}" "$Program_B -b ${Paramater_B[@]}"



close



echo

echo -e "e[33m========================================e[0m"

echo -e "e[33mReading output file from diske[0m"

echo -e "e[33m========================================e[0m"

echo

cat $OUTPUT_FILE

The console output is this:

$ ./test.sh

foo -a --spam --egg=4

bar -b --ham --spice=4



foo -a --spam

foo -a --spam --egg=4

foo -a --spam --egg=4 bar -b --ham --spice=4



========================================

Reading output file from disk

========================================



echo "foo -a --spam"

echo "foo -a --spam" "--egg=4"

echo "foo -a --spam --egg=4 bar -b --ham --spice=4"

So what I see is, that ".... ${Parameter_A[@]} ..." is contained in a string, but breaks the string into multiple strings. That's Why $1 in the procedure contains the string including the first parameter value.

How to embed all parameters into a single string without breaking it up into multiple strings?

$@ works to print all texts, because it contains all parameters passed to the procedure. However, it's not a solutions to me, because I can not distinguish when the string from $2 starts or in other words, how many parts belong to $1.

As proposed by Cyrus, I used shellcheck.net to check my Bash script.

Here is the output from the checker:

$ shellcheck myscript



Line 24:

    echo "echo "$@"" >&3

                 ^-- SC2145: Argument mixes string and array. Use * or separate argument.



Line 33:

    --egg=4

    ^-- SC2191: The = here is literal. To assign by index, use ( [index]=value ) with no spaces. To keep as literal, quote it.



Line 39:

    --spice=4

    ^-- SC2191: The = here is literal. To assign by index, use ( [index]=value ) with no spaces. To keep as literal, quote it.



Line 44:

echo "$Program_A -a ${Paramater_A[@]}"

                    ^-- SC2145: Argument mixes string and array. Use * or separate argument.



Line 45:

echo "$Program_B -b ${Paramater_B[@]}"

                    ^-- SC2145: Argument mixes string and array. Use * or separate argument.



Line 47:

procedure1 "$Program_A -a ${Paramater_A[@]}" "$Program_B -b ${Paramater_B[@]}"

                          ^-- SC2145: Argument mixes string and array. Use * or separate argument.

>>                                                          ^-- SC2145: Argument mixes string and array. Use * or separate argument.



Line 48:

procedure2 "$Program_A -a ${Paramater_A[@]}" "$Program_B -b ${Paramater_B[@]}"

                          ^-- SC2145: Argument mixes string and array. Use * or separate argument.

>>                                                          ^-- SC2145: Argument mixes string and array. Use * or separate argument.



Line 49:

procedure3 "$Program_A -a ${Paramater_A[@]}" "$Program_B -b ${Paramater_B[@]}"

                          ^-- SC2145: Argument mixes string and array. Use * or separate argument.

>>                                                          ^-- SC2145: Argument mixes string and array. Use * or separate argument.

It shows that the used @ needs to be changed to *. @ contained in double quotes expands to each array element contained in double quotes, whereas * expands into the string.