An Overview of GNU Software

As a Red Hat Linux user, you may not realize the extent to which Red Hat Linux (and, for that matter, all Linux distributions) relies on GNU software. Nearly all tasks you perform in a Red Hat Linux system involve one or more GNU software packages. For example, the GNOME GUI and the Bash shell are both GNU software. If you rebuild the kernel or develop software, you do so with the GNU C and C++ compiler and the make utility; both are parts of the GNU software packages that accompany all Linux distributions. If you edit text files with the ed or Emacs editor, you are again using a GNU software package. The list goes on and on. It’s a safe bet that when you are using any Linux system, you are running some GNU software all the time.

If you are wondering what GNU is, here’s the scoop. GNU is a recursive acronym that stands for GNU’s Not Unix. The GNU Project was launched in 1984 by Richard Stallman to develop a complete UNIX-like operating system. The GNU Project developed nearly everything needed for a complete operating system except for the operating system kernel. All GNU software was distributed under the GNU General Public License (GPL). GPL essentially requires that the software be distributed in source-code form and stipulates that any user can copy, modify, and distribute the software to anyone else in source-code form. Users may, however, have to pay for their copy of GNU software.

The Free Software Foundation (FSF) is a tax-exempt charity that raises funds for work on the GNU Project. To learn more about the GNU Project, visit their home page at http://www.gnu.org/. There you can find information about how to contact the Free Software Foundation and how you can help the GNU Project.

One way to appreciate the extent of GNU software in Linux is to take stock of various GNU software packages. Table 8-1 briefly describes some of the well-known GNU software packages that come with Red Hat Linux. You can browse the table to get a feel for the types of tasks you can perform with GNU software.

Table 8-1: Well-Known GNU Software Packages
Software Package	Description
Autoconf	Generates shell scripts that automatically configure source-code packages
Automake	Generates Makefile.in files for use with Autoconf
Bash	The default shell—command interpreter—in Red Hat Linux. (Bash is compatible with the UNIX sh shell and offers many extensions found in csh and ksh shells.)
bc	An interactive calculator with arbitrary precision numbers
Binutils	A package that includes several utilities for working with binary files: ar, as, gasp, gprof, ld, nm, objcopy, objdump, ranlib, readelf, size, strings, and strip
gnuchess	A chess-playing program that regularly beats many good players
GNU C Library	For use with all Linux programs
cpio	Copies file archives to and from disk or to another part of the file system
diff	Compares files, showing line-by-line changes in several different formats
ed	A line-oriented text editor
Emacs	An extensible, customizable full-screen text editor and computing environment
Fileutils	A package that implements the following Linux commands: chgrp, chmod, chown, cp, dd, df, dir, dircolors, du, install, ln, ls, mkdir, mkfifo, mknod, mv, rm, rmdir, sync, touch, and vdir
Findutils	A package that includes the find, locate, and xargs utilities
Finger	A utility program designed to enable users of UNIX systems (including Red Hat Linux) on the Internet to get information about one another
Gawk	The GNU Project’s implementation of the AWK programming language that conforms to the definition of the language in the POSIX 1003.2 Command Language and Utilities Standard
GCC	Compilers for C, C++, Objective C, and other languages
gdb	Source-level debugger for C, C++ and Fortran
gdbm	A replacement for the traditional dbm and ndbm database libraries
gettext	A set of utilities that enables software maintainers to internationalize a software package’s user messages
Ghostscript	An interpreter for the Postscript and Portable Document Format (PDF) languages
Ghostview	An X Window System application that provides a graphical front end to Ghostscript, and enables users to view Postscript or PDF files in a window
The GIMP	The GNU Image Manipulation Program is an Adobe Photoshop-like image-processing program
GNOME	Provides a GUI for a wide variety of tasks that a Linux user might perform
Gnumeric	A graphical spreadsheet (similar to Microsoft Excel) that works in GNOME and can work with Excel 95 format files
grep package	Includes the grep, egrep, and fgrep commands that are used to find lines that match a specified text pattern
Groff	A document formatting system similar to troff
GTK+	A GUI toolkit for the X Window System (used to develop GNOME applications)
gzip	A GNU utility for compressing and decompressing files
indent	Formats C source code by indenting it in one of several different styles
less	A page-by-page display program similar to more, but with additional capabilities
libpng	A library for image files in the Portable Network Graphics (PNG) format
m4	An implementation of the traditional UNIX macro processor that is commonly used to create the sendmail configuration file
make	A utility that determines which files of a large software package need to be recompiled, and issues the commands to recompile them
mtools	A set of programs that enables users to read, write, and manipulate files on a DOS file system (typically a floppy disk, but also Windows partitions of hard drives)
ncurses	A package for displaying and updating text on text-only terminals
patch	A GNU version of Larry Wall’s program to take the output of diff and apply those differences to an original file to generate the modified version
RCS	The Revision Control System is used for version control and management of source files in software projects
sed	A stream-oriented version of the ed text editor
sharutils	A package that includes shar (used to make shell archives out of many files), unshar (to unpack these shell archives), as well as uuencode and uudecode utilities (some open source software installers need uudecode)
shellutils	A package that includes the following utilities, which are part of the Bash shell: basename, chroot, date, dirname, echo, env, expr, factor, false, groups, hostname, id, logname, nice, nohup, pathchk, printenv, printf, pwd, seq, sleep, stty, su, tee, test, true, tty, uname, uptime, users, who, whoami, and yes
tar	A tape archiving program that includes multivolume support; the capability to archive sparse files, handle compression and decompression, and create remote archives; and other special features for incremental and full backups
texinfo	A set of utilities that generates printed manuals, plain ASCII text, and online hypertext documentation (called Info), and that enables users to view and read online Info documents
textutils	A set of utilities such as cut, join, nl, split, tail, wc, and so on, for manipulating text
time	A utility that reports the user, system, and actual time a process uses