All data in UNIX is organized into files. All files are organized into directories. These directories are organized into a tree-like structure called the filesystem.
When you work with UNIX, one way or another you spend most of your time working with files. This tutorial would teach you how to create and remove files, copy and rename them, create links to them etc.
In UNIX there are three basic types of files:
Ordinary Files: An ordinary file is a file on the system that contains data, text, or program instructions. In this tutorial, you look at working with ordinary files.
Directories: Directories store both special and ordinary files. For users familiar with Windows or Mac OS, UNIX directories are equivalent to folders.
Special Files: Some special files provide access to hardware such as hard drives, CD-ROM drives, modems, and Ethernet adapters. Other special files are similar to aliases or shortcuts and enable you to access a single file using different names.
Listing Files:
To list the files and directories stored in the current directory. Use the following command:
$ls
Here is the sample output of the above command:
$ls
bin hosts lib res.03
ch07 hw1 pub test_results
ch07.bak hw2 res.01 users
docs hw3 res.02 work
The command ls supports the -l option which would help you to get more information about the listed files:
$ls -l
total 1962188
drwxrwxr-x 2 amrood amrood 4096 Dec 25 09:59 uml
-rw-rw-r-- 1 amrood amrood 5341 Dec 25 08:38 uml.jpg
drwxr-xr-x 2 amrood amrood 4096 Feb 15 2006 univ
drwxr-xr-x 2 root root 4096 Dec 9 2007 urlspedia
-rw-r--r-- 1 root root 276480 Dec 9 2007 urlspedia.tar
drwxr-xr-x 8 root root 4096 Nov 25 2007 usr
drwxr-xr-x 2 200 300 4096 Nov 25 2007 webthumb-1.01
-rwxr-xr-x 1 root root 3192 Nov 25 2007 webthumb.php
-rw-rw-r-- 1 amrood amrood 20480 Nov 25 2007 webthumb.tar
-rw-rw-r-- 1 amrood amrood 5654 Aug 9 2007 yourfile.mid
-rw-rw-r-- 1 amrood amrood 166255 Aug 9 2007 yourfile.swf
drwxr-xr-x 11 amrood amrood 4096 May 29 2007 zlib-1.2.3
$
Here is the information about all the listed columns:
First Column: represents file type and permission given on the file. Below is the description of all type of files.
Second Column: represents the number of memory blocks taken by the file or directory.
Third Column: represents owner of the file. This is the Unix user who created this file.
Fourth Column: represents group of the owner. Every Unix user would have an associated group.
Fifth Column: represents file size in bytes.
Sixth Column: represents date and time when this file was created or modified last time.
Seventh Column: represents file or directory name.
When you work with UNIX, one way or another you spend most of your time working with files. This tutorial would teach you how to create and remove files, copy and rename them, create links to them etc.
In UNIX there are three basic types of files:
Ordinary Files: An ordinary file is a file on the system that contains data, text, or program instructions. In this tutorial, you look at working with ordinary files.
Directories: Directories store both special and ordinary files. For users familiar with Windows or Mac OS, UNIX directories are equivalent to folders.
Special Files: Some special files provide access to hardware such as hard drives, CD-ROM drives, modems, and Ethernet adapters. Other special files are similar to aliases or shortcuts and enable you to access a single file using different names.
Listing Files:
To list the files and directories stored in the current directory. Use the following command:
$ls
Here is the sample output of the above command:
$ls
bin hosts lib res.03
ch07 hw1 pub test_results
ch07.bak hw2 res.01 users
docs hw3 res.02 work
The command ls supports the -l option which would help you to get more information about the listed files:
$ls -l
total 1962188
drwxrwxr-x 2 amrood amrood 4096 Dec 25 09:59 uml
-rw-rw-r-- 1 amrood amrood 5341 Dec 25 08:38 uml.jpg
drwxr-xr-x 2 amrood amrood 4096 Feb 15 2006 univ
drwxr-xr-x 2 root root 4096 Dec 9 2007 urlspedia
-rw-r--r-- 1 root root 276480 Dec 9 2007 urlspedia.tar
drwxr-xr-x 8 root root 4096 Nov 25 2007 usr
drwxr-xr-x 2 200 300 4096 Nov 25 2007 webthumb-1.01
-rwxr-xr-x 1 root root 3192 Nov 25 2007 webthumb.php
-rw-rw-r-- 1 amrood amrood 20480 Nov 25 2007 webthumb.tar
-rw-rw-r-- 1 amrood amrood 5654 Aug 9 2007 yourfile.mid
-rw-rw-r-- 1 amrood amrood 166255 Aug 9 2007 yourfile.swf
drwxr-xr-x 11 amrood amrood 4096 May 29 2007 zlib-1.2.3
$
Here is the information about all the listed columns:
First Column: represents file type and permission given on the file. Below is the description of all type of files.
Second Column: represents the number of memory blocks taken by the file or directory.
Third Column: represents owner of the file. This is the Unix user who created this file.
Fourth Column: represents group of the owner. Every Unix user would have an associated group.
Fifth Column: represents file size in bytes.
Sixth Column: represents date and time when this file was created or modified last time.
Seventh Column: represents file or directory name.
