Shell Programming and Scripting

Of course, which is what I was trying to warn you about.

Hm. $0 is a special variable, which tells the script how it was run. If you typed in ./programs/myscript.sh then $0 is just that, ./programs/myscript.sh. Or if you typed in /usr/local/sbin/myscript.sh then it gets given that.

So if the first character of $0 is a /, you have the full path in that string and just need to extract it. If it begins with anything else, the string "${PWD}/$0" will contain the full path. So you can extrapolate it from inside the script itself, doesn't need to be fed into it.

---------- Post updated at 09:47 PM ---------- Previous update was at 09:44 PM ----------

First method doesn't "find" anything, it just assumes you're already there.

The second method does the same thing, since "cd $PWD" is a complete no-op. You're already in $PWD, that's what $PWD means.

So you're not finding it, you just happen to already be where you wanted to be...

Extrapolate it from $PWD and $0 as described above instead

...and that didn't actually work. Nvm. When I ran it, I got this error:
For the first one, it said that ~/hi didn't exist (the file was actually in ~/Destkop/testfolder/hi)
For the second one, it said that cd ~/Desktop/testfolder/main ./hi didn't exist, which I'm assuming means it tried to find hi inside main as if it were a directory

Read my above post. Neither versions went anywhere. Also read my post that tells you how to really do it.

Oh, that makes sense.
Except for one thing. Wouldn't that make the path "....../myscript.sh", so that when you do ./2ndscript.sh, it tries to find ...../myscript.sh/2ndscript.sh, which doesn't exist?

I have no idea where you found six periods in my example.

You can nest paths like /path/to/wherever/./it/is/ fine. The extra ./ just does nothing.

---------- Post updated at 10:06 PM ---------- Previous update was at 09:56 PM ----------

This should work.

Code:

#!/bin/sh

BASE=$(basename "$0")

if [ "${0:0:1}" == "/" ]
then
        BASE=${0%%${BASE}}
else
        BASE="${PWD}/${0%%${BASE}}"
fi

echo $BASE

my problem isn't with your example. The combination of $PWD and $0 looks good. It's with a problem that neither your example nor what I tried to do took into account. When I got my error, it was because I was trying to treat myscript.sh as a directory, and look for 2ndscript.sh INSIDE myscript.sh. What happened was when I cd'ed into $PWD, it changed the path to ~/Desktop/testfolder/myscript.sh. I wanted it to simply cd into ~/Desktop/testfolder, so that when I did ./2ndscript.sh, the full path would be ~/Desktop/testfolder/2ndscript.sh But when the path was to ~/Destkop/testfolder/myscript.sh, and then i did ./2ndscript.sh, it tried to execute the command as ~/Desktop/testfolder/myscript.sh/2ndscript.sh

I said you had to extract it from the strings. $0 provides the whole input, filename included. If you didn't bother to remove the filename, naturally that didn't work.

Read my example above which shows you how to do so. It extracts the first character of $0 to find out if it's a relative or absolute path, and assembles the path out of $PWD or just $0 accordingly. It find the filename alone with basename, then strips that out of the path with ${var%%stringtoremove}.