Midnight Commander - The File Manager
Philipp Thomas
Introduction
The Midnight Commander, or in short, mc, stands in a
long tradition of text-based file managers whose common ancestor is
the Norton Commander for DOS. They all share the basic layout, with a
menu bar at the upper margin, two large windows for displaying files
or information, a command line and a key assignment display in the
bottom line.
Anyone familiar with Norton Commander will feel at home
immediately with Midnight Commander. In contrast to its
ancestor, mc, as a Linux program, sports a number of additional
features:
- Display of directories exported by external computers using NFS.
- Connection to external computers via FTP and representation of FTP
directory trees in the window.
- Display of Tar archives, Cpio archives and RPM packages as a file
tree.
- Support of Unix-specific operations such as changing
the owner (chown) or the permissions (chmod) of a
file, and the creation of hard and symbolic links (links and
symlinks).
In addition, Midnight Commander offers far more
configuration possibilities than its ancestor.
Configuration
Here are the first measures you should take following the first
call-up of Midnight Commander. Press the F9 key to
activate the menu and select Options. A window will appear with the
configuration options. In the Configuration menu a vast amount of
options are offered:
Window Options
| Display backup copies: |
Many programs, for example editors such
as vi or joe, create backup copies. These files end with
'~'. They are usually not displayed by Midnight Commander. |
| Display hidden files: |
Files beginning with a dot are usually
not displayed, as in Linux the dot marks them as hidden files. |
| Downward marking: |
In the default setting, the selection bar
automatically moves downwards if a file is highlighted (either with
the Insert key or with Ctrl+c). If this option is
deactivated, the bar remains where it is. |
| Dropdown menus: |
If you activate this option, a dropdown
menu will appear immediately after pressing F9. If you
deactivate this option, only the menu bar is activated, and you must
first select a menu before the window is opened. |
| All files mixed: |
If this option is active, no distinction
is made between files and directories on the display. Is it inactive,
directories (and links to directories) are always displayed first. |
| Quick read: |
This option is usually inactive. When
activated, Midnight Commander uses a trick to determine whether the
directory content has changed. The directory will only be re-loaded
once its i-node has changed. This trick causes the display to be
refreshed only when a file is deleted or newly created, but not when a
file changes (size, owner, access rights, etc.). In these cases, the
display has to be refreshed manually (with Ctrl+r). |
Pause after call-up
Following the execution of commands, the Midnight Commander can pause
to give you a chance to view the output of these commands. There are
three possible settings for this option:
| Never: |
Means that you never want to view the
output of your commands. When you use the Linux console or a terminal
window, you can view the output by using Ctrl+o. |
| On dumb terminals: |
On such terminals (for the Midnight Commander this means anything
which is neither a Linux console nor a terminal window), which are
incapable of showing the output of the last executed command, the
Midnight Commander pauses and issues a pause message. |
| Always: |
It always pauses. |
Other Options
| Verbose operations: |
This option specifies whether a dialog window is displayed for each
of the processes of copying, renaming or deleting files. If you are
working on a slow terminal, you may wish to close this window. This
option is automatically de-activated if your terminal is working at a
speed lower than 9600 bps. |
| Calculating grand totals: |
When this option is activated, the Midnight Commander calculates the
total size and the number of files affected before all file
operations. In this way you receive a precise progress report, at the
expense of just a little time. |
| Shell patterns: |
The select, deselect and filter commands normally use regular
expressions similar to those provided by the shell. The following
conversions are made to bring this about:
* is replaced by .* (zero or more characters),
? is replaced by . (exactly one character) and
. stands for a full stop.
When this option is deactivated, the regular expressions correspond
to those of the ed program (see man ed). |
| Saving settings
automatically: |
When this option
is active, the Midnight Commander automatically saves all
configuration options in the ini file located in the
.mc subdirectory of your home directory. |
| Auto menus: |
If this option is activated, the user
menu is automatically opened after the start of the Midnight
Commander. |
| Using the internal editor: |
Specifies whether you want to use the
built-in editor or an external one to edit files. When this option is
deactivated, the Midnight Commander uses the editor specified
in the EDITOR environment variable. If no editor is
specified, the Midnight Commander uses the vi
editor. |
Using the internal viewer: |
If you do not wish to use the built-in
viewer to view files, this option should be deactivated. The Midnight
Commander then uses the viewer specified in the PAGER
environment variable. If this is not specified, the view program is
used. |
| Total: displaying everything: |
The Midnight Commander usually
shows all possible completions when the input is ambiguous after
pressing Esc-Tab or Alt-Tab twice. After the first
time, it completes only as far as possible and beeps in case of
ambiguity. If you wish to see all possible completions immediately
after pressing Esc-Tab or Alt-Tab once, this option
should be activated. |
| Rotating bar: |
This specifies whether the Midnight
Commander should display a rotating bar in the upper right hand corner
when it is busy with an operation (e.g., when reading a large
directory). |
| lynx-type movements: |
When this option is active, you can use
the cursor keys to change to a directory, if the selection bar is on a
directory and the command line is empty. |
| Extended chown: |
Specifies whether the extended
chown command is called when the chown or
chmod command is executed. This extended chown
combines chmod and chown in a single window in which
owner/group and access rights can be set simultaneously. |
| cd follows links: | When this option is active, the Midnight
Commander follows the logical chain of directories in the same way
that bash does. When it is deactivated, the Midnight Commander follows
the actual directory structure. That means that a cd .. takes you to
the real parent directory if you have reached a directory via a
symbolic link, and not to the directory in which the link was located. |
| Safe deletion: |
If active, unintentional deletion of
files is made more difficult. The default button in the confirmation
dialog changes from the Yes to the No button, and
when deleting directories which are not empty, the word Yes
must be typed in.
|
The representation options are self-explanatory. I would only like to
stress the options for partitioning windows. In Linux, the names
of files and directories can become very long. By splitting the
display window vertically, the Midnight Commander may have to
abbreviate names. However, if you split the window horizontally, the
wide windows provide far more display space for long names.
Working with these horizontal windows may be somewhat unfamiliar, but
displaying more information of names makes up for this.
Possibly the most important configuration options are hidden behind
the Display bits menu entry. Here you can determine whether the Midnight
Commander displays and lets you enter special national characters.
You should select ISO 8859-1 for output and activate the
complete 8 bit entry option.
The description of the remaining configuration options would go
beyond the scope of this introduction, please refer to the on-line
help.
Working with the Midnight Commander
Now that the Midnight Commander has been configured, you will
undoubtedly want to know what can be done with it.
Navigation can be carried out either with the keyboard or the
mouse. Therefore, you can select a directory either with the
Enter key or by double-clicking the left mouse button. You
switch between windows with the Tab key. You can mark or
unmark individual files with the Insert key. With the '+' key
you can select whole groups of files via a dialog window, deselect
groups with the '-' key and invert your selection with the '*' key. If
you wish to delete the contents of a directory, retaining only a small
number of the files, you first mark the files you wish to keep. Now
press '*', the selection will be inverted, the files you previously
selected will be unmarked, and the selected remainder can be
safely disposed of with the F8 key.
Working with menus can sometimes be too circumstantial to the more
experienced user. Here the command line of the Midnight Commander
enters the scene. All commands can be entered in the same way you are
familiar with from working with the console or in a terminal window.
However, the Midnight Commander offers several additional
possibilities. You can copy the name of the directory displayed in one
of the windows into the command line, using Ctrl-x,
Ctrl-p for the inactive window, Ctrl-x, p for the
active window. You can copy the names of all selected files in the
active window into the command line with Ctrl-x, t , and
those of the inactive window with Ctrl-x,
Ctrl-t.
If you want to copy all the selected files in the active window
into a directory which is not currently displayed, having just enter
mv Ctrl-x,t desired directory in the command line
after having carried out the selection, and confirm with the Enter
key.
Furthermore, if you want to mark any information in the mc
display to be copied, you only need to keep pressing the left mouse
button while highlighting. Then the text can be highlighted and
copied just as you would in the console or in the terminal window.
Navigation through packed files (tar, rpm, zip)
Now the Midnight Commander cannot only navigate through real
directories, but it also allows you, via its virtual file system, to
treat archives as real directories which have been created by
compression programs such as Zip or Tar. This also applies to files in
RPM format (the packages on your CDs). You select the file with the
Enter key. At the beginning you're just presented the
information that is directly contained in the RPM package. Open its
subdirectoty INFO for information regarding version and
ChangeLog etc. In case, the particular package contained scripts being
executed at the times of installation or deinstallation, those can be
found under INFO/SCRIPTS. Back in the main directory you
won't find that much information at first, but it's here where the
actual package lies, CONTENTS.cpio. It may now take a while
for the Midnight Commander to extract the file. It then shows
the contents of the package in the active window, and you can move
around in the file as if it was a normal directory. So you can, for
example, easily copy a single file from a Zip, Tar or RPM archive, or
view it using F3.
You can also access FTP servers in the same way. You can either
select FTP connection from the menu of the appropriate window (menu
item Left/Right or Up/Down), or you can enter a
special form of the cd command. If you choose to use the menu, you can
enter the URL in the subsequent dialog window. Enter the name of the
FTP server here, and an anonymous connection is made. If a log-on with
user name is required, enter username@computername. The
Midnight Commander will then ask for a password. This can be
entered directly by typing username:password@computername, but then
other people present might be able to read your password, so this
method is strongly discouraged.
If, instead, you wish to establish an FTP connection via the command
line, just use cd in combination with an URL that can be used in Web
browsers such as Netscape. Two examples:
cd ftp://ftp.gwdg.de
cd ftp://philipp@my.computer/my/homedirectory
When the connection is made, you can move through the directories of
the FTP server as if you were in your local file system, and access, copy
or delete files (provided you have the appropriate access privileges).
However, you should note that you cannot apply any external commands
to files inside such virtual directories, but only commands built
into the Midnight Commander. This means that the command line is not
available!
Have Fun!
This was just a quick trip through the most interesting possibilities
of the Midnight Commander. It offers you many additional possibilities
which you will discover only with time. Studying the on-line help and
the Midnight Commander documentation will bring even more unknown
capabilities to light, which I highly recommend. For many users, at
least, the Midnight Commander has become an indispensable tool and is
something they would not want to do without during their everyday
work, and you might well soon feel the same.
|
|
|
Contact 
