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## 11. The Remaining 1%

Much more than 1%, actually...

## 11.1 Running DOS/Windows Apps

Yes, you can to some extent run DOS and Windows applications under Linux! There are two emulators that are quite good: Dosemu ( http://www.dosemu.org) and Wine ( http://www.winehq.com). The latter is getting better release after release, and the list of runnable applications is getting larger. It even runs Word and Excel!

## 11.2 Using tar and gzip

Under UNIX there are some widely used applications to archive and compress files. `tar` is used to make archives---it's like `PKZIP` or `Winzip`but it doesn't compress, it only archives. To make a new archive:

> `

>     $ tar cvf <archive_name.tar> <file> [file...]

> `

To extract files from an archive:

> `

>     $ tar xvf <archive_name.tar> [file...]

> `

To list the contents of an archive:

> `

>     $ tar tf <archive_name.tar> | less

> `

You can compress files using `compress`, which is obsolete and shouldn't be used any more, or `gzip`: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 can compress only one file at a time. To decompress:

> `

>     $ compress -d <file.Z>
>     $ gzip -d <file.gz>

> `

RMP.

There are also the `unarj`, `zip` and `unzip` (PK??ZIP compatible) utilities. Files with extension `.tar.gz` or `.tgz` (archived with `tar`, then compressed with `gzip`) are as common in the UNIX world as .ZIP files are under DOS. Here's how to list the contents of a `.tar.gz` archive:

> `

>     $ tar ztf <file.tar.gz> | less

> `

## 11.3 Installing Applications

First of all: installing packages is root's work. Most Linux applications are distributed as a `.tar.gz` archive, which typically will contain a directory aptly named containing files and/or subdirectories. A good rule is to install these packages from `/usr/local` with the command

> `

>     # tar zxf <archive.tar.gz>

> `

reading then the README or INSTALL file. In most cases, the application is distributed in source, which you'll have to compile; often, typing `make` then `make install` will suffice. If the archive contains a `configure` script, run it first. Obviously, you'll need the `gcc` or `g++` compiler.

Other archives have to be unpacked from /; this is the case with Slackware's `.tgz` archives. Other archives contain the files but not a subdirectory - careful not to mess things up! Always list the contents of the archive before installing it.

Debian and Red Hat have their own archive format; respectively, `.deb` and `.rpm`. The latter is widely used by many distributions; to install an `rpm` package, type

> `

>     # rpm -i package.rpm

> `

## 11.4 Tips You Can't Do Without

Backscrolling: pressing <SHIFT + PAG UP> (the grey key) allows you to backscroll a few pages, depending on how much video memory you have.

Resetting the screen: if you happen to `more` or `cat` a binary file, your screen may end up full of garbage. To fix it, blind type `reset` or this sequence of characters: `echo CTRL-V ESC c RETURN`.

Pasting text: in console, see below; in X, click and drag to select the text in an `xterm` window, then click the middle button (or the two buttons together if you have a two-button mouse) to paste. There is also `xclipboard` (alas, only for text); don't get confused by its very slow response.

Using the mouse: if you installed `gpm`, a mouse driver for the console, you can click and drag to select text, then right click to paste the selected text. It works across different VCs.

Messages from the kernel: have a look at `/var/adm/messages` or `/var/log/messages` as root to see what the kernel has to tell you, including bootup messages. The command `dmesg` is also handy.

## 11.5 Where to Find Applications

If you're wondering whether you can replace your old and trusted DOS/Win application with a Linux one, I suggest that you browse the main Linux software repository: ftp://metalab.unc.edu/pub/Linux. Other good starting places are the ``Linux Applications and Utilities Page'' http://www.xnet.com/~blatura/linapps.shtml, the ``official'' Linux page http://www.linux.org, and http://freshmeat.net.

## 11.6 A Few Things You Couldn't Do

Linux can do an awful lot of things that were cumbersome, difficult or impossible do to with DOS/Windows. Here's a short list that may whet your appetite:

- `at` allows you to run programs at a specified time;
- `awk` is a simple yet powerful language to manipulate data files (and not only). For example, being `data.dat` your multi field data file,

  > `

  >     $ awk '$2 ~ "abc" {print $1, "\t", $4}' data.dat

  > `

  prints out fields 1 and 4 of every line in `data.dat` whose second field contains ``abc''.
- `cron` is useful to perform tasks periodically, at specified date and time. Type `man 5 crontab`.
- `file <filename>` tells you what `filename` is (ASCII text, executable, archive, etc.);
- `find` (see also Section Directories: Translating Commands) is one of the most powerful and useful commands. It's used to find files that match several characteristics and perform actions on them. General use of `find` is:

  > `

  >     $ find <directory> <expression>

  > `

  where <expression> includes search criteria and actions. Examples:

  > `

  >     $ find . -type l -exec ls -l {} \;

  > `

  finds all the files that are symbolic links and shows what they point to.

  > `

  >     $ find / -name "*.old" -ok rm {} \;

  > `

  finds all the files matching the pattern and deletes them, asking for your permission first.

  > `

  >     $ find . -perm +111

  > `

  finds all the files whose permissions match 111 (executable).

  > `

  >     $ find . -user root

  > `

  finds all the files that belong to root. Lots of possibilities here---RMP.
- `grep` finds text patterns in files. For example,

  > `

  >     $ grep -l "geology" *.tex

  > `

  lists the files *.tex that contain the word ``geology''. The variant `zgrep` works on gzipped files. RMP;
- regular expressions are a complex but darn powerful way of performing search operations on text. For example, `^a[^a-m]X{4,}txt$` matches a line that starts with `a', followed by any character except those in the interval a-m, followed by 4 or more `X', and ends in `txt'. You use regular expressions with advanced editors, `less`, and many other applications. `man grep` for an introduction.
- `script <script_file>` dumps the screen contents on `script_file` until you issue the command `exit`. Useful for debugging;
- `sudo` allows users to perform some of root's tasks (e.g. formatting and mounting disks; RMP);
- `uname -a` gives you info about your system;
- `zcat` and `zless` are useful for browsing and piping gzipped files without decompressing them. For example:

  > `

  >     $ zless textfile.gz
  >     $ zcat textfile.gz | lpr

  > `

- The following commands often come in handy: `bc, cal, chsh, cmp, cut, fmt, head, hexdump, nl, passwd, printf, sort, split, strings, tac, tail, tee, touch, uniq, w, wall, wc, whereis, write, xargs, znew.` RMP.

## 11.7 Practicing UNIX under DOS/Win

Believe it or not, there are fine tools that provide a UNIX-like environment under DOS/Windows! One is the Djgpp suite ( http://www.delorie.com/djgpp/) for DOS, while Cygwin ( http://www.cygnus.com/cygwin) is a more complex port for Win32. Both include the same GNU development tools and utilities as Linux; you won't get the same stability and performance, though.

If you'd like to have a taste of Linux, try out Djgpp. Download and install the following files (as of this writing, the latest version is 2.02): `djdev202.zip, bnu281b.zip, bsh1147b.zip, fil316b.zip, find41b.zip, grep22b.zip, gwk303b.zip, lss332b.zip, shl112b.zip.`. Installation instructions are provided, and you can find assistance on news:comp.os.msdos.djgpp.

In particular, using `bash` under DOS/Win is a whiff of fresh air. To configure it properly, edit the supplied file `BOOT.BAT` to reflect your installation, then put these files in your home directory (in the Windows partition) instead of those provided:

> `

>     # this is _bashrc

>     LS_OPTIONS="-F -s --color=yes"
>     alias cp='cp -i'
>     alias d='ls -l'
>     alias l=less
>     alias ls="ls $LS_OPTIONS"
>     alias mv='mv -i'
>     alias rm='rm -i'
>     alias u='cd ..'

> `

> `

>     # this is _bprof
>     if [ -f ~/_bashrc ]; then
>       . ~/_bashrc
>     fi
>     PS1='\w\$ '
>     PS2='> '
>     CDPATH="$CDPATH:~"
>     # stuff for less(1)
>     LESS="-M-Q"                     # long prompt, silent
>     LESSEDIT="%E ?lt+%lt. %f"       # edit top line
>     VISUAL="jed"                    # editor
>     LESSCHARSET=latin1              # visualise accented letters
>     export PS1 PS2 CDPATH LS_OPTIONS LESS LESSEDIT LESSOPEN VISUAL LESSCHARSET

> `

## 11.8 Common Extensions and Related Programs

You may come across scores of file extensions. Excluding the more exotic ones (i.e. fonts, etc.), here's a list of who's what:

- `1 ... 8`: man pages. Read them with `groff -Tascii -man <file.1>`.
- `arj`: archive made with `arj`.
- `dvi`: output file produced by TeX (see below). `xdvi` to visualise it; `dvips` to turn it into a PostScript `.ps` file.
- `gz`: archive made with `gzip`.
- `info`: info file (sort of alternative to man pages). Get `info`.
- `lsm`: Linux Software Map file. It's a plain ASCII file containing the description of a package.
- `ps`: PostScript file. To visualise or print it get `gs` and, optionally, `ghostview` or `gv`.
- `rpm`: Red Hat package. You can install it on any system using the package manager `rpm`.
- `taz, tar.Z`: archive made with `tar` and compressed with `compress`.
- `tgz, tar.gz`: archive made with `tar` and compressed with `gzip`.
- `tex`: text file to submit to TeX, a powerful typesetting system. Get the package `tex`, available in many distributions.
- `texi`: texinfo file, can produce both TeX and info files (cp. `info`). Get `texinfo`.
- `xbm, xpm, xwd`: graphic file.
- `Z`: archive made with `compress`.

## 11.9 Converting Files

If you need to exchange text files between DOS/Win and Linux, be aware of the ``end of line'' problem. Under DOS, each line of text ends with CR/LF (that is, ASCII 13 + ASCII 10), with LF under Linux. If you edit a DOS text file under Linux, each line will likely end with a strange--looking `M' character; a Linux text file under DOS will appear as a kilometric single line with no paragraphs. There are a couple of tools, `dos2unix` and `unix2dos`, to convert the files.

If your text--only files contain accented characters, make sure they are made under Windows (with Notepad) and not under plain DOS; otherwise, all accented characters will be screwed up.

## 11.10 Free Office Suites

Yes, you can have for free what would otherwise cost a lot of money!

StarOffice ( http://www.sun.com/staroffice.) is currently the only choice, though Koffice is down the pipeline ( http://www.koffice.org). StarOffice is big and slow, but very good anyway: it offers a lot of functionality not found in Microsoft Office. It can also read and write Word and Excel files, although the conversion isn't always perfect.

Another good package is Corel WordPerfect, a free edition of which is available for download. Need I say more? Go fetch it: http://www.corel.com.

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