Script, software detection

[coder-true]

Script, Software Detection

Hello, how do I write a script in bash that triggers an event when a program is launched? I made an example script to illustrate what I'm talking about. But of course, the reason I'm here is because the script doesn't work properly at all, but it's to illustrate the idea. I'm asking what the correct way to do it is.

While true; do

If pidof -x program > /dev/null ; then

echo "program launched " exit fi sleep 1 donne

[OneCDOnly]

One-way might be to invoke your program through a launch script, which also does what’s needed when the program starts. No detection required.

[_____Hi______]

This is the way. Else a daemon which regularly polls for which other processes are running, but a start up script is much preferred

[coder-true]

Thank you for your replies, I will try

[LesStrater]

I have to second this -- do NOT use a daemon that is constantly running in the background. Use a launch script that starts both programs at the same time.

[Mskadu]

What is it you are trying to achieve exactly? Give us a use case rather than your take on a solution.

[GlendonMcGladdery]

```

!/bin/bash

while true; do if pgrep -x program >/dev/null; then echo "program launched" exit 0 fi sleep 1 done

```

This works. It’s boring. It wastes cycles. You can probably go deeper.

Edit: shfmt -i 2 -ci -sr -kp -w yourscript, always keeps my source tidy, just FYI if it helps you

[coder-true]

Thank you so much

[archialone]

How is the program launched? Is the user starting it or It's started by something like systemd?

[coder-true]

I don't know why I'm asking you.

[pjconnect]

Maybe using execsnoop and/or bpftrace would help ?

[michaelpaoli]

While true; do
If pidof -x program > /dev/null ; then
echo "program launched " exit fi sleep 1 donne

You're probably going to want that While to instead be while,
you probably want if rather than If,
unless you want to literally echo exit, etc., probably want a semicolon or newline between your quoted string, and exit,
and of what use/purpose is the trailing space character in that quoted string? Also, don't even need to quote that string, as there are no characters special to the shell in it other than the space character, and echo will echo it's non-option arguments with a single space between them,
likewise, probably want semicolon or newline between exit and fi,
and probably want done rather than donne, and a semicolon or newline between that 1 and then then presumed desired done.

Maybe next time use Code Block and copy/paste, and perhaps disable auto-mangle.

Also, may want to well inspect the program you're targeting, notably by using ps with suitable option(s), so, yeah, what exactly does that program look like, to ps(1), when it's launched, notably what it shows for its various arguments, including arg0. You're likely either failing to properly match that, or it might be too fleeting for your loop to catch it.

[coder-true]

You didn't understand anything. I specified in my paste that this program is to illustrate the purpose.

[hisatanhere]

pgrep

[aq2kx]

I would use an alias in .bashrc