Linux FAQ - Section 8
Miscellaneous information and questions answered

Question 8.1. How do I program XYZ under Linux ?

Read the manuals, or a good book on Unix. manpages (type man man) are usually a good source of reference information on exactly how to use a particular command or function.

There is also a lot of GNU Info documentation, which is often more useful as a tutorial. Run Emacs and type C-h i, or type info info if you don't have or don't like Emacs. Note that the Emacs libc node doesn't exactly describe the Linux libc (which is more like a traditional Unix libc, not having some of the GNU oddities), but it's close enough to make a fair tutorial in Unix C programming.

The latest release of the Linux manpages and a collection of useful GNU Info documentation various other information related to programming Linux can be found on sunsite.unc.edu in /pub/Linux/docs/man-pages.

Question 8.2. What's all this about ELF ?

See the ELF HOWTO by Daniel Barlow - note, this is not the file move-to-elf, which is a blow-by-blow account of how to upgrade to ELF manually.

Linux is switching to a different format for executables, object files and object code libraries, known as `ELF' (the old format is called `a.out'). This will have many advantages, including better support for shared libraries and dynamic linking.

Both a.out and ELF binaries can coexist on a system. However, they use different shared C libraries, both of which will have to be installed to do this.

If you want to find out whether your system can run ELF binaries, look in /lib for a filename libc.so.5. If this exists it probably can. If you want to know whether your installation actually is ELF you can pick a representative program, like ls, and run file on it: 

   -chiark:~> file /bin/ls
   /bin/ls: Linux/i386 impure executable (OMAGIC) - stripped

   valour:~> file /bin/ls
   /bin/ls: ELF 32-bit LSB executable, Intel 80386, version 1, stripped
There is a patch to get 1.2.x to compile using the ELF compilers, and produce ELF coredumps, on tsx-11.mit.edu in /pub/packages/GCC. You do not need the patch merely to run ELF binaries. 1.3.x and later do not need a patch at all.

Question 8.3. What is a .gz file ? And a .tgz ? And ... ?

.gz (and .z) files have been compressed using GNU gzip. You need to use gunzip (which is as a symlink to the gzip command which comes with most Linux installations) to unpack the file.

.taz and .tz are tarfiles (made with Unix tar) compressed using standard Unix compress.

.tgz (or .tpz) is a tarfile compressed with gzip.

.lsm is a Linux Software Map entry, in the form of a short text file. Details about the LSM and the LSM itself are available in the docs subdirectory on sunsite.unc.edu.

.deb is a Debian Binary Package - the binary package format used by the Debian GNU/Linux distribution. It is manipulated using dpkg and dpkg-deb (available on Debian systems and from ftp.debian.org).

.rpm is a Red Hat RPM package, which is used in the Red Hat distribution. These can be found on ftp.redhat.com.

The file command can often tell you what a file is.

If you find that gzip complains when you try to uncompress a gzipped file you probably downloaded it in ASCII mode by mistake. You must download most things in binary mode - remember to type binary as a command in FTP before using get to get the file.

Question 8.4. What does VFS stand for ?

Virtual File System. It's the abstraction layer between the user and real filesystems like ext2, minix and msdos. Amongst other things, its job is to flush the read buffer when it detects a disk change on the floppy disk drive: 
   VFS: Disk change detected on device 2/0

Question 8.5. What is a BogoMip ?

`BogoMips' is a contraction of `Bogus MIPS'. MIPS stands for (depending who you listen to) Millions of Instructions per Second, or Meaningless Indication of Processor Speed.

The number printed at boot-time is the result of a kernel timing calibration, used for very short delay loops by some device drivers.

As a very rough guide the BogoMips will be approximately: 

     386SX              clock * 0.14
     386DX              clock * 0.18
     486Cyrix/IBM       clock * 0.33
     486SX/DX/DX2       clock * 0.50
     586                clock * 0.39
If the number you're seeing is wildly lower than this you may have the Turbo button or CPU speed set incorrectly, or have some kind of caching problem [as described in Q6.5 `When I add more memory it slows to a crawl.'.]

For values people have seen with other, rarer, chips, see the BogoMips Mini-HOWTO, on sunsite.unc.edu in /pub/Linux/docs/howto/mini/BogoMips.

Question 8.6. What is the Linux Journal and where can I get it ?

Linux Journal is a monthly magazine (printed on paper) that is available on newsstands and via subscription worldwide. Email linux@ssc.com for details. They are on the Web at http://www.ssc.com/.

Question 8.7. How many people use Linux ?

Linux is freely available, and no one is required to register their copies with any central authority, so it is difficult to know. Several businesses are now surviving solely on selling and supporting Linux, and very few Linux users use those businesses, relatively speaking. The Linux newsgroups are some of the most heavily read on the Net, so the number is likely in the hundreds of thousands, but firm numbers are hard to come by.

However, one brave soul, Harald T. Alvestrand Harald.T.Alvestrand@uninett.no, has decided to try, and asks that if you use Linux, you send a message to linux-counter@uninett.no with one of the following subjects: `I use Linux at home', `I use Linux at work', or `I use Linux at home and at work'. He will also accept `third-party' registrations - ask him for details.

Alternatively, you can register using the WWW forms found at http://domen.uninett.no/~hta/linux/counter.html.

He posts his counts to comp.os.linux.misc each month; alternatively look on aun.uninett.no in /pub/misc/linux-counter or at the web page above.

Question 8.8. How should I pronounce Linux ?

This is a matter of religious debate, of course !

If you want to hear Linus himself say how he pronounces it download english.au or swedish.au from ftp.funet.fi (in /pub/OS/Linux/PEOPLE/Linus/SillySounds). If you have a soundcard or the PC-speaker audio driver you can hear them by typing 

   cat english.au >/dev/audio
The difference isn't in the pronunciation of Linux but in the language Linus uses to say hello. The English version was parodied very well by Jin Choi as "Hi, my name is Leenoos Torvahlds and I pronounce Leenooks as Leenooks."

For the benefit of those of you who don't have the equipment or inclination: Linus pronounces Linux approximately as Leenus, where the ee is as in feet but rather shorter and the u is like a much shorter version of the French eu sound in peur (pronouncing it as the u in put is probably passable).

When speaking English I pronounce it Lie-nucks (u as in bucket) --- this is an anglicised pronunciation based on the analogy with Linus' name, which in English is usually pronounced Lie-nus (u as in put). It is of course quite acceptable and common to modify the pronunciation of a proper noun when it changes languages.

I think I can safely say that the pronunciation Linnucks (short i as in pit, short u as in bucket) is wrong in English, as it is not the original Swedish pronunciation, not a sensible direct anglicisation of it, and not based on the anglicised version of Linus' name.

Next: Frequently encountered error messages.
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Ian Jackson / ijackson@gnu.ai.mit.edu - 06 March 1996

Extracted from Linux Frequently Asked Questions with Answers, Copyright Ian Jackson 1996.