Hi,
I'm a beginners, this is one of my first script, it's easy, but I don't know how to write this script:

The script receive in input 4 parameters:
1) user_name
2) r and/or w and/or x ( rwx, rw, x, ....)
3) u and/or g and/or o ( u, uo, ugo, ...)
4) the path name

The script print a list of normal files ( “-” with ls) created by user_name, with at least the permission specified as 2nd parameters for the groups specified as 3rd parameter , starting from the path name passed as 4th parameter.

Example of permission:
giving: rw, u
I look for “ rw-......“ using ls -lr (. is a generic character)
giving: rw, ugo
I look for “ rw-rw-rw- “

I tryed in many ways, but for example i f I execute a simple script like this:
permission=-rw-r--r--
ls -lR | grep '^-$permission'

The script don't print anything on the screen, but I type in the shell:
ls -lR | grep '^-rw-r--r--'
the output is correct.

Moreover I don't know how to separate the colums of ls -lR using CUT (I suppose) to select oly the rows that are created by the user

So I understood I need help. Please help me.
PS: i have to write many script, and this is the simplest, so if I don't know how to write this, I'll never be able to write the others..