Linux and Unix Shell Programming

1.1. Files

When you create a file the system stores all the information you could ever want to know about it, including:

• The location of the file;

• File type;

• File size;

• Who owns it and can access it;

• The inode;

• Time last modified; and

• The permission bits of the file.

Let’s look at a typical file listing, using the ls -l command:

						$ ls -l 
total 4232 
-rwxr-xr-x   1 root   root     3756  Oct 14 04:44 dmesg 
-r-xr-xr-x   1 root   root     12708 Oct  3 05:40 ps 
-rwxr-xr-x   1 root   root     5388  Aug  5  1998 pwd 
.... 

If we go through the output of the first two lines a step at a time, we can break down the information ls -l gives us.

total 4232	This field tells us how much space the files have taken up in the directory.
-rwxr-xr-x	This is the permission bits on the file. If you ...