I need to make a bash script to replace a certain application.
Script should do some work and then execute said application in a way that everything (parameters both positional and named, env variables, signals etc.) will work as if it was the original application executed.

My idea was to do it like this:

#!/bin/bash

# Do something custom
export PATH=/some/custom/override:$PATH

# Execute the original script
exec php8.1 $@

Is this enough or should I do something else to ensure a perfect substitution?

CodePudding user response：

You should check your scripts with shellcheck .

Line 7:
exec php8.1 $@
            ^-- SC2068 (error): Double quote array expansions to avoid re-splitting elements.

Use:

exec php8.1 "$@"

CodePudding user response：

• If PATH is empty or unset, your code adds an empty path entry (after :), causing the current directory to always be in PATH.

• You should set PATH like: export PATH=/my/path${PATH :$PATH}, or export PATH=/my/path${PATH: :$PATH}.

• The first one avoids an empty entry if PATH is unset, but not if it has already been set to empty. The second one always avoids an empty PATH entry.

• Although it's unlikely PATH will be unset or empty, if you want "perfect substitution", you should use the first example. If you believe empty PATH is always a bug for your application, you could use the second example.

• Apart from that, exec command "$@" is pretty standard (add quotes as already mentioned).