Question

Problem

I would like to use the parameters given to a script as is – with quotes and everything. So far, all solutions I found strip the quotes, or do something subtly different.

Scenario

I have a tool that accepts strings as command line parameters, for instance

./tool --formula="AG EF phi;"

I further have a wrapper script that should call the script. Its invocation should be

wrap.sh ./tool --formula="AG EF phi;"

This script does something like

# preparation phase
# ...

# call tool and remember exit code
$*
result=$?

# evaluation phase
# ...

exit $result

Unfortunately, the tool is then called as

./tool --formula=AG EF phi;

which is not the same as above and would yield a syntax error. The only hacks I found would give me something like

./tool "--formula=AG EF phi;"

which is also wrong.

Details

To be concrete, here is some dummy code to exemplify the problem:

First, the C program “tool.c”.

#include <stdio.h>

int main(int argc, char** argv) {
    int i;
    for (i = 0; i < argc; i++) {
        printf("%d: %s\n", i, argv[i]);
    }
    return 0;
}

Then, the wrap script “wrap.sh”:

#!/bin/bash
echo $*
$*
exit $?

Now here is what I tried:

$ ./tool --formula="Foo bar"
0: ./tool
1: --formula=Foo bar

$ ./wrap.sh ./tool --formula="Foo bar"
./tool --formula=Foo bar
0: ./tool
1: --formula=Foo
2: bar

$ ./wrap.sh ./tool --formula="\"Foo bar\""
./tool --formula="Foo bar"
0: ./tool
1: --formula="Foo
2: bar"

$ ./wrap.sh ./tool --formula="\"Foo bar\""
./tool --formula="Foo bar"
0: ./tool
1: --formula="Foo
2: bar"

$ ./wrap.sh "./tool --formula=\"\\\"Foo bar\\\"\""
./tool --formula="\"Foo bar\""
0: ./tool
1: --formula="\"Foo
2: bar\""

And here is what I want (for whatever necessary change in the wrap script):

$ ./wrap.sh ./tool --formula="Foo bar"
0: ./tool
1: --formula=Foo bar

Proposals

Escape Quotes

When I escape quotes like Shabaz proposed, the variable $* contains correctly quoted strings, for instance:

wrap.sh ./tool --formula="\"AG EF phi;\""

and then in wrap.sh the code:

echo $*

would produce

./tool --formula="AG EF phi;"

However, executing $* produces the exact error as above: The argument of formula is stripped after “AG”. Furthermore, it would be nice not to escape quotes.

Could a different shell help?

Answer 1

You can use this script that works to preserve the white-spaces you want:

#!/bin/bash
exec bash -c "$*"
ret=$?
exit $ret

Execute above script using this command line:

./wrap.sh ./tool --formula="\"Foo bar baz\""

OUTPUT:

0: ./tool
1: --formula=Foo bar baz