How can I add an argument for executable linux file-CodePudding

I have a executable linux file called "Fyserver". I want to open it with this arg

./Fyserver --pass 2849

If I don't enter this --pass arg to ELF, then it should exit itself without even running. Is there a way to do this?

NOTE: I don't have the source code of this ELF. I want to do it in bash.

CodePudding user response：

There is no sane way to do what you are asking. You can't add new behavior to a binary without access to the source code or some serious reverse engineering skills.

The usual solution is to create a simple wrapper, i.e. move ./Fyserver to ./Fyserver.real and create a script like

#!/bin/sh
[ "$1" = "--pass" ] || { echo "Syntax: $0 --pass <pass>" >&2; exit 127; }
exec ./Fyserver.real "$@"

The argument checking could arguably be more sophisticated, but this should at least give you an idea of how this is usually handled.

If you really wanted to, I suppose you could write this logic in a compiled language, and embed the original binary within it somehow.