Bash scripting - what is "$#" ?
 

Hi,

I'm encountering this line in a script:

When I echo this to stdio on my system, $# is always 0; but it's a boottime script and when I echo & save the output, it is always 4. I'm new to bash scripting and this isn't my script; I'm just trying to debug why some stuff isn't working as I expect. I doubt this is the cause but I'm still curious what variable this might refer to.

Also if this is something I could Google, I would appreciate some good keywords to try. Being new to bash I didn't know what to look for, and symbols like $# together don't work.

Cheers!

It means the number of parameters on the command line when the script is called.

Check the link in my signature for the Bash reference.

jlinkels

Great, thanks a ton :)
Excellent reference, I'll start digesting it tonight!

Please mark as SOLVED once you have a solution.

Yeah, that line basically says "while any arguments were given from command-line, do..."

And just by the way, $1, $2, $3, etc is the specific argument on the command-line, e.g arg1, arg2, arg3, and so on. And $@ is the entire string of arguments, e.g. "arg1 arg2 arg3 arg4" and so on.