-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 At some point hitherto, Michael Bovee hath spake thusly: > Okay, apologies in advance, but something I _just dont get_ is the > PATH variable. > (I'm a born and raised Macintosh user so please bear with me) > I bought a SAMS Teach Yourself book on Unix, but it says nothing > about WHY this PATH thing is even necessary. (Under MacOS... if I > invoke the 'FIND' command it just looks everywhere all the time)
The PATH variable is necessary because each directory you want to find executables in has to be processed to see if the file exists there. You don't want the system to look in every directory, because there are LOTS of them, and finding the command you want to run would take a very, very long time that way. > For example, I tried running commands the SuSE 7.3 (for PPC) manual > tells me to use for configuring stuff like my PCMCIA network card and > all I get back is - command not found. But it HAS to be there, > somewhere. Doesn't work as regular user or as root. Well actually, no it doesn't have to be there. It may be part of a package that didn't get installed by default. Some distributions, for example, will not install PCMCIA related software unless you specify a "laptop install" or specifically request them (actually I think this is largely untrue now, but I believe it used to be the case). > Why is it not the default that the system can look *everywhere*? Or > more to the point, why would my followed-the-rules install of SuSE > Linux 7.3 not be already configured to allow me to do the very things > the printed manual says should work? Now that's a really good question! But there is a logical answer, believe it or not. Some commands that you can run on a Unix/Linux system are *EXTREMELY DANGEROUS* if you don't know what you're doing. You don't want to be running these commands by accident, as it will likely break your system permanently. So, for the newbie, it's a good idea that these commands NOT be in the default PATH. If you can't find a command, try $ whereis <command> If that doesn't turn it up, try $ locate command If it's on the system, one of these should generally find it. The first looks in pre-defined locations, generally those places where commands tend to live, to see if the file can be found. The second looks up anything that matches <command> in a database of all files on your system. > TIA, I appreciate the willingness of experts on this mailing list to > stoop to my level! Though we sometimes forget, we were all once newbies... ;-) - -- Derek Martin [EMAIL PROTECTED] - --------------------------------------------- I prefer mail encrypted with PGP/GPG! GnuPG Key ID: 0x81CFE75D Retrieve my public key at http://pgp.mit.edu Learn more about it at http://www.gnupg.org -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQE8u1pDdjdlQoHP510RAu/HAKC70MZPyVig8cxTMtc080H4+OXPTACgm0Jv FbZYibMYM+uDRyjpdtioxJQ= =XF6k -----END PGP SIGNATURE----- ***************************************************************** To unsubscribe from this list, send mail to [EMAIL PROTECTED] with the text 'unsubscribe gnhlug' in the message body. *****************************************************************
