less
You'll use this file browser every day, so I'll give you a couple of tips to
use it at best. First of all, ask your sysadm to configure less so as
it can display not only plain text files, but also compressed files,
archives, and so on.
Like recent versions of TYPE, less lets you browse files
in both directions. It also accepts several commands that are issued
pressing a key. The most useful are:
q to leave the browser;
h gives you extensive help;
g to go to beginning of file, G to the end, number+g
to go to line `number' (e.g. 125g), number+% to move to that
percentage of the file;
/pattern searches forwards for `pattern'; n searches
forwards for the next match; ?pattern and N search backwards;
m+letter marks current position (e.g. ma); '+letter go
to the marked position.
:e examines a new file;
!command executes the shell command.
Alas, Linux doesn't still support file version numbers, but you overcome this limitation in two ways. The first is to use RCS, the Revision Control System, which allows you to keep previous versions of a file. RCS is covered in ``The RCS MINI-HOWTO'' ( http://sunsite.unc.edu/mdw/HOWTO/mini/RCS.html).
The second way is to use an editor that knows how to deal with numbered
backups; emacs and jed are OK. In emacs, add
these lines in your .emacs:
(setq version-control t)
(setq kept-new-versions 15) ;;; or any other value
(setq kept-old-versions 15)
(setq backup-by-copying-when-linked t)
(setq backup-by-copying-when-mismatch t)
In jed, make sure you have version 0.98.7 or newer; the patch for
numbered backups is available on
http://ibogeo.df.unibo.it/guido/slang/backups.sl .
Under UNIX there are some widely used applications to archive and
compress files. tar is used to make archives, that is collections of
files. To make a new archive:
$ tar -cvf <archive_name.tar> <file> [file...]
To extract files from an archive:
$ tar -xpvf <archive_name.tar> [file...]
To list the contents of an archive:
$ tar -tf <archive_name.tar> | less
Files can be compressed to save disk space using compress, which is
obsolete and shouldn't be used any more, or gzip:
$ compress <file>
$ gzip <file>
that creates a compressed file with extension .Z (compress) or .gz
(gzip). These programs don't make archives, but compress files
individually. To decompress, use:
$ compress -d <file.Z>
$ gzip -d <file.gz>
RMP.
The unarj, zip and unzip utilities are also available. Files
with extension .tar.gz or .tgz (archived with tar, then
compressed with gzip) are very common in the UNIX world. Here's how to
list the contents of a .tar.gz archive:
$ tar -ztf <file.tar.gz> | less
To extract the files from a .tar.gz archive:
$ tar -zxf <file.tar.gz>