Slackware Linux Essentials: Tutorial 10

Chapter 10 Handling Files and Directories
Table of Contents
10.1 Navigation : ls, cd, and pwd
10.2 Pagers: more, less, and most
10.3 Simple Output: cat and echo
10.4 Creation: touch and mkdir
10.5 Copy and Move
10.6 Deletion: rm and rmdir
10.7 Aliasing files with ln
Linux aims to the most Unix-like it can be. Traditionally, Unix operating systems have been command-line oriented. We do have a graphical user interface in Slackware, but the command-line is still the main level of control for the system. Therefore, it is important to understand some of the basic file management commands.

The following sections explain the common file management commands and provide examples of how they are used. There are many other commands, but these will help you get started. Also, the commands are only briefly discussed here. You will find more detail in the accompanying man pages for each command.

10.1 Navigation : ls, cd, and pwd
10.1.1 ls
This command lists files in a directory. Windows and DOS users will notice its similarity to the dir command. By itself, ls(1) will list the files in the current directory. To see what's in your root directory, you could issue these commands:

% cd /
% ls
bin cdr dev home lost+found proc sbin tmp var
boot cdrom etc lib mnt root suncd usr vmlinuz


The problem a lot of people have with that output is that you cannot easily tell what is a directory and what is a file. Some users prefer that ls add a type identifier to each listing, like this:

% ls -FC
bin/ cdr/ dev/ home/ lost+found/ proc/ sbin/ tmp/ var/
boot/ cdrom/ etc/ lib/ mnt/ root/ suncd/ usr/ vmlinuz


Directories get a slash at the end of the name, executable files get an asterisk at the end of the name, and so on.

ls can also be used to get other statistics on files. For example, to see the creation dates, owners, and permissions, you would look at a long listing:

% ls -l
drwxr-xr-x 2 root bin 4096 May 7 09:11 bin/
drwxr-xr-x 2 root root 4096 Feb 24 03:55 boot/
drwxr-xr-x 2 root root 4096 Feb 18 01:10 cdr/
drwxr-xr-x 14 root root 6144 Oct 23 18:37 cdrom/
drwxr-xr-x 4 root root 28672 Mar 5 18:01 dev/
drwxr-xr-x 10 root root 4096 Mar 8 03:32 etc/
drwxr-xr-x 8 root root 4096 Mar 8 03:31 home/
drwxr-xr-x 3 root root 4096 Jan 23 21:29 lib/
drwxr-xr-x 2 root root 16384 Nov 1 08:53 lost+found/
drwxr-xr-x 2 root root 4096 Oct 6 12:47 mnt/
dr-xr-xr-x 62 root root 0 Mar 4 15:32 proc/
drwxr-x--x 12 root root 4096 Feb 26 02:06 root/
drwxr-xr-x 2 root bin 4096 Feb 17 02:02 sbin/
drwxr-xr-x 5 root root 2048 Oct 25 10:51 suncd/
drwxrwxrwt 4 root root 487424 Mar 7 20:42 tmp/
drwxr-xr-x 21 root root 4096 Aug 24 03:04 usr/
drwxr-xr-x 18 root root 4096 Mar 8 03:32 var/


Suppose you want to get a listing of the hidden files in the current directory. This command will do just that:

% ls -a
. bin cdrom home mnt sbin usr
.. boot dev lib proc suncd var
.pwrchute_tmp cdr etc lost+found root tmp vmlinuz


Files beginning with a period (called dot files) are hidden when you run ls. You will only see them if you pass the -a option.

There are many more options that can be found in the online manual page. Don't forget that you can combine options that you pass to ls.

10.1.2 cd
The cd command is used to change working directories. You simply type cd followed by the path name to change to. Here are some examples:

darkstar:~$ cd /bin
darkstar:/bin$ cd usr
bash: cd: usr: No such file or directory
darkstar:/bin$ cd /usr
darkstar:/usr$ ls
bin
darkstar:/usr$ cd bin
darkstar:/usr/bin$


Notice that without the preceding slash, it tries to change to a directory in the current directory. Also executing cd with no options will move you to your home directory.

The cd command is not like the other commands. It is a builtin shell command. Shell builtins are discussed in Section 8.3.1. This may not make any sense to you right now. Basically it means there is no man page for this command. Instead, you have to use the shell help. Like this:

% help cd


It will display the options for cd and how to use them.

10.1.3 pwd
The pwd command is used to show your current location. To use the pwd command just type pwd. For example:

% cd /bin
% pwd
/bin
% cd /usr
% cd bin
% pwd
/usr/bin



http://www.slackbook.org/html/file-commands.html