This posting contains answers to general information and availability questions. The following questions are answered in this posting:
Perl is a compiled scripting language written by Larry Wall*.
Here's the beginning of the description from the perl(1) man page:
Perl is an interpreted language optimized for scanning arbi- trary text files, extracting information from those text files, and printing reports based on that information. It's also a good language for many system management tasks. The language is intended to be practical (easy to use, effi- cient, complete) rather than beautiful (tiny, elegant, minimal). It combines (in the author's opinion, anyway) some of the best features of C, sed, awk, and sh, so people familiar with those languages should have little difficulty with it. (Language historians will also note some vestiges of csh, Pascal, and even BASIC-PLUS.) Expression syntax corresponds quite closely to C expression syntax. Unlike most Unix utilities, perl does not arbitrarily limit the size of your data--if you've got the memory, perl can slurp in your whole file as a single string. Recursion is of unlimited depth. And the hash tables used by associative arrays grow as necessary to prevent degraded performance. Perl uses sophisticated pattern matching techniques to scan large amounts of data very quickly. Although optimized for scanning text, perl can also deal with binary data, and can make dbm files look like associative arrays (where dbm is available). Setuid perl scripts are safer than C programs through a dataflow tracing mechanism which prevents many stupid security holes. If you have a problem that would ordinarily use sed or awk or sh, but it exceeds their capa- bilities or must run a little faster, and you don't want to write the silly thing in C, then perl may be for you. There are also translators to turn your sed and awk scripts into perl scripts. OK, enough hype.
Perl4 and perl5 are different versions of the language. Perl4 was the previous release, and perl5 is "Perl: The Next Generation." Perl5 is, essentially, a complete rewrite of the perl source code from the ground up. It has been modularized, object oriented, tweaked, trimmed, and optimized until it almost doesn't look like the old code. However, the interface is mostly the same, and compatibility with previous releases is very high.
If you get the newest source (from any of the main FTP sites), you will find a directory full of man pages (possibly to be installed as section 1p and 3pm) that discuss the differences, new features, old incompatibilies and much more. Here, however, are some highlights as to the new feature and old incompatibilites.
(Thanks to Tom Christiansen* for this section)
The complete perl documentation is available with the Perl distribution, or can be accessed from the following sites. Note that the PerlDoc ps file is 240 pages long!!
http://www.metronet.com/0/perlinfo/perl5/manual/perl.html ftp://ftp.uu.net/languages/perl/PerlDoc.ps.gz ftp://prep.ai.mit.edu/pub/gnu/PerlDoc.ps.gz ftp://ftp.cbi.tamucc.edu/pub/duff/Perl/PerlDoc.ps.gz ftp://www.metronet.com/pub/perlinfo/perl5/manual/PerlDoc.ps.gz http://web.nexor.co.uk/perl/perl.html (Europe) ftp://ftp.zrz.tu-berlin.de/pub/unix/perl/PerlDoc.ps.gz (Europe) ftp://ftp.cs.ruu.nl/pub/PERL/perl5.0/PerlDoc.ps.gz (Europe) ftp://sungear.mame.mu.oz.au/pub/perl/doc/PerlDoc.ps.gz (Oz)
In general, no. However, certain bad old practices have become highly frowned upon. The following are the most important of the known incompatibilies between perl4 and perl5. See perltrap(1) for more details.
When asked at what point the Perl code would be frozen, Larry answere:
Part of the redesign of Perl is to *allow* us to more or less freeze the language itself. It won't totally freeze, of course, but I think the rate of change of the core of the language is asymptotically approaching 0. In fact, as time goes on, now that we have an official extension mechanism, some of the things that are currently in the core of the language may move out (transparently) as extensions. This has already happened to dbmopen().
I've also been continuously reminding myself of what Henry Spencer calls "second system syndrome", in which everything under the sun gets added, resulting in a colossal kludge, like OS 360. You'll find that the new features in Perl 5 are all pretty minimalistic. The object-oriented features in particular added only one new piece of syntax, a C++-style method call.
: The whole idea : Perl is to be a fast text-processing, system-maintenance, zero-startup : time language. If it gets to be so large and complicated that it isn't : fast-running and easy to use, it won't be to anyone's benefit.
My motto from the start has been, "If it ain't broke, don't fix it." I've been trying very hard not to remove those features from Perl that make it what it is. At the same time, a lot of streamlining has gone into the syntax. The new yacc file is about half the size of the old one, and the number of official reserved words has been cut by 2/3. All built-in functions have been unified (dualified?) as either list operators or unary operators.
: I really like a lot of the features in Perl, but in order for Perl to : be useful on a long term basis, those features have to stay put. I : bought the Camel book less than a year ago and it sounds like within : another year it will be obsolete.
The parts of Perl that the Camel book covers have not changed all that much. Most old scripts still run. Many scripts from Perl version 1.0 still run. We'll certainly be revising the Camel, but the new man pages are split up such that it's pretty easy to ferret out the new info when you want it.
We did break a few misfeatures in going to Perl 5. It seemed like the first and last chance to do so. There's a list of the incompatibilities in the documentation.
: Not only is it a lot of work to recompile Perl : on 20+ machines periodically, but it's hard to write scripts that are : useful in the long term if the guts of the language keep changing. : (And if I keep having to buy new books. I keep hearing about new : features of Perl 5 that aren't documented in any of the perl 5 : documentation that *I* can find.)
I think you'll find a lot of folks who think that 4.036 has been a pretty stable platform.
Perl 5 is a special case. I've been working on it for years. (This is part of the reason 4.036 has been so stable!) There are many changes, most of them for the better, I hope. I don't expect the transition to be without pain. But that's why I stuck numbered versions out in your bin directory, so that you can upgrade piecemeal if you like. And that's why I made the -w switch warn about many of the incompatibilities.
And overriding all that, I've tried to keep it so that you don't have to know much about the new stuff to use the old stuff. You can upgrade your *knowledge* piecemeal too.
The extension mechanism is designed to take over most of the evolutionary role from now on. And it's set up so that, if you don't have a particular extension, you know it right up at the front.
: Are there any plans to write a Perl compiler? While interpreted Perl : is great for many applications, it would also be cool to be able to : precompile many scripts. (Yes, I know you can undump things, but : undump isn't provided with Perl and I haven't found a copy.) The : creation of a perl library and dynamically-loadable modules seems : like a step in that direction.
Yes, part of the design of Perl 5 was to make it *possible* to write a compiler for it. It could even be done as an extension module, I suppose. Anyone looking for a master's thesis topic?
In summary, almost every concern that you might think of has already been (at least) thought about. In a perfect world, every concern could be addressed perfectly. But in this world we just have to slog through.
32! [ ord('p') - ord('P') ] (Shouldn't that be 42, the Answer to the Great Question of Life, the Universe, and Everything? ;)
Larry now uses "Perl" to signify the language proper and "perl" the implementation of it, i.e. the current interpreter. Hence Tom's quip that "Nothing but perl can parse Perl."
On the other hand, the aesthetic value of casewise parallelism in "awk", "sed", and "perl" as much require the lower-case version as "C", "Pascal", and "Perl" require the upper-case version. It's also easier to type "Perl" in typeset print than to be constantly switching in Courier. :-)
In other words, it doesn't matter much, especially if all you're doing is hearing someone talk about the language; case is hard to distinguish aurally.
It depends on whether you are talking about the perl binary or something that you wrote using perl. And, actually, even this isn't necessarily true.
"Standard" UNIX terminology is (roughly) this: programs are compiled into machine code once and run multiple times, scripts are translated (by a program) each time they are used. However, some say that a program is anything written which is executed on a computer system. Larry considers it a program if it is set in stone and you can't change it, whereas if you can go in and hack at it, it's a script. Of course, if you have the source code, that makes just about anything a script. ;)
In general, it probably doesn't really matter. The terms are used interchangeably. If you particularly like one or the other, use it. If you want to call yourself a perl programmer, call them programs. If you want to call yourself a perl scripter, call them scripts. Randal* and I (at least) will call them hacks. (See question 2.10 ;)
Not at all. Many people find Perl extremely easy to learn. There are at least three main reasons for this.
The first reason is that most of Perl has been derived from standard utilities, tools, and languages that you are (probably) already familiar with. If you have any knowledge of the C programming language and standard C library, the Unix Shell, sed and awk, Perl should be simple and fun for you to learn.
The second reason that Perl is easy to learn is that you only have to know a very small subset of Perl to be able to get useful results. In fact, once you can master
#!/usr/local/bin/perl print "Hello, world\n";
you can start writing Perl scripts. In fact, you will probably never have to (or be able to) know everything about Perl. As you feel the need or desire to use more sophisticated features (such as C structures or networking), you can learn these as you go. The learning curve for Perl is not a steep one, especially if you have the headstart of having a background in UNIX. Rather, its learning curve is gentle and gradual, but it *is* admittedly rather long.
The third reason is that you can get immediate results from your scripts. Unlike a normal compiled language (like C or Pascal, for example), you don't have to continually recompile your program every time you change one little thing. Perl allows you to experiment and test/debug quickly and easily. This ease of experimentation flattens the learning curve even more.
If you don't know C or UNIX at all, it'll be a steeper learning curve, but what you then learn from Perl will carry over into other areas, like using the C library, UNIX system calls, regular expressions, and associative arrays, just to name a few. To know Perl is to know UNIX, and vice versa.
Most definitely. In fact, you should delete the binaries for sed, awk, cc, gcc, grep, rm, ls, cat... well, just delete your /bin directory.
But seriously, of course you shouldn't. As with any job, you should use the appropriate tool for the task at hand. Just because a hammer will put screws into a piece of board, you probably don't want to do that.
While it's true that the answer to the question "Can I do (some arbitrary task) in Perl?" is almost always "yes", that doesn't mean this is necessarily a good thing to do. For many people, Perl serves as a great replacement for shell programming. For a few people, it also serves as a replacement for most of what they'd do in C. But for some things, Perl just isn't the optimal choice, such as tasks requiring very complex data structures.
REXX is an interpreted programming language first seen on IBM systems. Python is an interpreted programming language by Guido van Rossum*. TCL is John Ousterhout*'s embeddable command language, designed just for embedded command extensions, but lately used for larger applications. TCL's most intriguing feature for many people is the tcl/tk toolset that allows for interpreted X-based tools. Others use it for its "expect" extension.
To avoid any flamage, if you really want to know the answer to this question, probably the best thing to do is try to write equivalent code to do a set of tasks. All three have their own newsgroups in which you can learn about (but hopefully not argue about) these languages.
To find out more about these or other languages, you might also check out David Muir Sharnoff*'s posting "Catalog of Compilers, Interpreters, and Other Language Tools" which he posts to comp.lang.misc, comp.sources.d, comp.archives.admin, and news.answers newsgroups. It's a comprehensive treatment of many different languages. (Caveat lector: he considers Perl's syntax "unappealing".)
Perl is available from any comp.sources.misc archive. You can use an archie server (see the alt.sources FAQ in news.answers) to find these if you want.
Volume Issues Patchlevel and Notes ------ ------ ------------------------------------------------ 18 19-54 Patchlevel 3, Initial posting. 20 56-62 Patches 4-10
Since 1993, a number of archives have sprung up specifically for Perl and Perl related items. Larry maintains the official distribution site (for both perl4.036 and perl5) at netlabs. Probably the largest archive is at the University of Florida. In order of probability these sites will have the sources.
Site IP Directory and notes ----------- ------- ------------------------------- North America: ftp.netlabs.com 184.108.40.206 /pub/outgoing/perl[VERSION]/ ftp.cis.ufl.edu 220.127.116.11 /pub/perl/src/[VERSION]/ prep.ai.mit.edu 18.104.22.168 /pub/gnu/perl5.000.tar.gz ftp.uu.net 22.214.171.124 /languages/perl/perl5.000.tar.gz ftp.khoros.unm.edu 126.96.36.199 /pub/perl/perl5.000.tar.gz ftp.cbi.tamucc.edu 188.8.131.52 /pub/duff/Perl/perl5.000.tar.gz ftp.metronet.com 184.108.40.206 /pub/perl/sources/ genetics.upenn.edu 220.127.116.11 /perl5/perl5_000.zip
Europe: ftp.cs.ruu.nl 18.104.22.168 /pub/PERL/perl5.0/perl5.000.tar.gz ftp.funet.fi 22.214.171.124 /pub/languages/perl/ports/perl5/perl5.000.tar.gz ftp.zrz.tu-berlin.de 126.96.36.199 /pub/unix/perl/perl5.000.tar.gz src.doc.ic.ac.uk 188.8.131.52 /packages/perl5/perl5.000.tar.gz
Australia: sungear.mame.mu.oz.au 184.108.40.206 /pub/perl/src/5.0/perl5.000.tar.gz
If there is a site in Asia or Japan, please tell us about it. Thanks!
You can also retrieve perl via non-ftp methods:
http: //src.doc.ic.ac.uk/packages/perl5/perl5.000.tar.gz gopher: //src.doc.ic.ac.uk/0/packages/perl5/perl5.000.tar.gz
The following is a list of known ftpmail sites. Please attempt to use the site closest to you with the ftp archive closest to it. Many of these sites already have perl on them. For information on how to use one of these sites, send email containing the word "help" to the address.
United States: Massachusetts: email@example.com New Jersey: firstname.lastname@example.org North Carolina: email@example.com
Europe/UK: Germany: firstname.lastname@example.org email@example.com UK: firstname.lastname@example.org
Henk P Penning* suggests that if you are in Europe you should try the following (if you are in Germany or the UK, you should probably use one of the servers listed above):
Email: Send a message to 'email@example.com' containing: begin path your_email_address send help send PERL/INDEX end The path-line may be omitted if your message contains a normal From:-line. You will receive a help-file and an index of the directory that contains the Perl stuff.
If all else fails, mail to Larry usually suffices.
There currently is no way of getting Perl via UUCP. If anyone knows of a way, please contact me. The OSU site has discontinued the service.
Another possibility is to use UUNET, although they charge you for it. You have been duly warned. Here's the advertisement:
Anonymous Access to UUNET's Source Archives
UUNET now provides access to its extensive collection of UNIX related sources to non- subscribers. By calling 1-900-468-7727 and using the login "uucp" with no password, anyone may uucp any of UUNET's on line source collection. Callers will be charged 40 cents per minute. The charges will appear on their next tele- phone bill.
The file uunet!/info/help contains instructions. The file uunet!/index//ls-lR.Z contains a complete list of the files available and is updated daily. Files ending in Z need to be uncompressed before being used. The file uunet!~/compress.tar is a tar archive containing the C sources for the uncompress program.
This service provides a cost effective way of obtaining current releases of sources without having to maintain accounts with UUNET or some other service. All modems connected to the 900 number are Telebit T2500 modems. These modems support all standard modem speeds including PEP, V.32 (9600), V.22bis (2400), Bell 212a (1200), and Bell 103 (300). Using PEP or V.32, a 1.5 megabyte file such as the GNU C compiler would cost $10 in con- nect charges. The entire 55 megabyte X Window system V11 R4 would cost only $370 in connect time. These costs are less than the official tape distribution fees and they are available now via modem.
UUNET Communications Services 3110 Fairview Park Drive, Suite 570 Falls Church, VA 22042 +1 703 876 5050 (voice) +1 703 876 5059 (fax) firstname.lastname@example.org
Perl runs on virtually all Unix machines simply by following the hints file and instructions in the Configure script. This auto-configuration script allows Perl to compile on a wide variety of platforms by modifying the machine specific parts of the code. For most Unix systems, or VMS systems for v5 perl, no porting is required. Try to compile Perl on your machine. If you have problems, examine the README file carefully. If all else fails, send a message to comp.lang.perl and crosspost to comp.sys.[whatever], there's probably someone out there that has already solved your problem and will be able to help you out.
Perl has been ported to many non-Unix systems, although currently there are no v5 ports. All of the following are mirrored at ftp.cis.ufl.edu:/pub/perl/src/[OS]/. The following are the (known) official distribution points. Please contact the porters directly (when possible) in case of questions on these ports.
* MS-DOS binaries and source are available at ftp.ee.umanitoba.ca [220.127.116.11] in /pub/msdos/perl There are currently half a dozen different ports for MS-DOS. BigPerl4 (v3) is perl4.036 compiled with the Watcom C/386 compiler (32-bit, flat-memory model C compiler) with the following features: * Up to 32MB of memory can be used. * Supports virtual memory. * Works under Windows 3.1 (however, a second copy of perl cannot be spawned under Windows). * The perl debugger can be used. * Contains GDBM support.
* Windows/NT binaries are available from ftp.cis.ufl.edu. Does anyone know the official distribution point? I got these from archive.cis.ohio-state.edu quite awhile back.
* Machintosh binaries and source are available from nic.switch.ch [18.104.22.168] in /software/mac/perl. Version 4.1.3 is perl4.036 compiled with the MPW C compiler * Mac_Perl_413_src.sit.bin Sources * Mac_Perl_413_tool.sit.bin MPW Tool * Mac_Perl_413_appl.sit.bin Standalone Application There is a mailing list for discussing Macintosh Perl. Contact "email@example.com".
Timothy Murphy* also ported a version of perl to the Macintosh using Think C. It has probably been abandoned in favour of the MPW port, but is still available at ftp.maths.tcd.ie [134.266.81.10] in the directory /pub/Mac/perl-4.035/.
* OS/2 sources are also available at ftp.cis.ufl.edu in /pub/perl/src/os2. This appears to have been abandoned and added to the official distribution. See the directory os2 in the perl5 sources.
* VMS systems should be able to build directly from the standard distribution.
The following directions are for perl, version 4. Perl, version 5, should compile more easily. If not, send mail to The Perl Porters Mailing List (firstname.lastname@example.org)
John Lees* reports:
I have built perl on Solaris 2.1, 2.2 beta, and 2.2 FCS. Take /usr/ucb out of your path and do not use any BSD/UCB libraries. Only -lsocket, -lnsl, and -lm are needed. You can use the hint for Solaris 2.0, but the one for 2.1 is wrong. Do not use vfork. Do not use -I/usr/ucbinclude. The result works fine for me, but of couse does not support a couple of BSDism's.
Casper H.S. Dik* reports
You must remove all the references to /usr/ucblib AND /usr/ucbinclude. And ignore the Solaris_2.1 hints. They are wrong. The undefining of vfork() probably has to do with the confusion it gives to the compilers. If you use cc, you mustn't compile util.c/tutil.c with -O. I only used the following libs: -lsocket -lnsl -lm (there is a problem with -lmalloc)
Michael D'Errico* reports:
If you are using Solaris 2.x, the signal handling is broken. If you set up a signal handler such as 'ripper' it will be forgotten after the first time the signal is caught. To fix this, you need to recompile Perl. Just add '#define signal(x,y) sigset((x),(y))' after the '#include <signal.h>' directive in each file that it occurs, then make it again.
According to Andreas Koenig*, under NeXTstep 3.2, both perl4.036 and perl5.000 compile with the supplied hints file.
However, Bill Eldridge* provides this message to help get perl4.036 on NeXTstep 3.0 to work:
To get perl to compile on NeXTs, you need to combine the ANSI and BSD headers:
cd /usr/include mkdir ansibsd cd ansibsd ln -s ../ansi ln -s ../bsd
Then, follow the configuration instructions for NeXTs, *replacing* all mention of -I/usr/include/ansi or -I/usr/include/bsd with -I/usr/include/ansibsd.
Some of the more popular extensions include those for windowing, graphics, or data base work. See perlmod(1).
Tk (as in tcl/tk, but sans tcl)
ftp://ftp.cis.ufl.edu/pub/perl/src/tkperl/tkperl5a5.tar.gz ftp://ftp.khoros.unm.edu/pub/perl/extensions/tkperl5a5.tar.gz ftp://ftp.metronet.com/pub/perlinfo/perl5/tkperl/tkperl5a5.tar.gz ftp://ftp.cs.ruu.nl/pub/PERL/perl5.0/tkperl5a5.tar.gz ftp://black.ox.ac.uk/src/ALPHA/tkperl5a5.tar.gz
Curses (standard C library) ftp://ftp.ncsu.edu/pub/math/wsetzer/cursperl5a6.tar.gz ftp://ftp.metronet.com/pub/perlinfo/perl5/cursperl5a6.tar.gz ftp://ftp.cs.ruu.nl/pub/PERL/perl5.0/cursperl5a6.tar.gz
Msql (SQL) ftp://ftp.zrz.TU-Berlin.DE/pub/unix/perl/MsqlPerl-a1.tgz ftp://ftp.khoros.unm.edu/pub/perl/extensions/MsqlPerl-a1.tgz ftp://ftp.metronet.com/pub/perlinfo/perl5/MsqlPerl5-a1.tgz ftp://ftp.cs.ruu.nl/pub/PERL/perl5.0/MsqlPerl-a1.tar.gz
Sx (Athena & Xlib) ftp://ftp.pasteur.fr/pub/Perl/Sx.tar.gz ftp://ftp.khoros.unm.edu/pub/perl/extensions/Sx.tar.gz ftp://ftp.metronet.com/pub/perlinfo/perl5/Sx.tar.gz ftp://ftp.cs.ruu.nl/pub/PERL/perl5.0/PerlDoc.ps.gz
Many database-oriented extensions to Perl have been written. Basically, these use the usub mechanism (see the usub/ subdirectory) in the source distribution) to link in a database library, allowing embedded calls to Informix, Ingres, Interbase, Oracle and Sybase.
Here are the authors of the various extensions:
What Target DB Who -------- ----------- ---------------------------------------- ?Infoperl Informix Kurt Andersen (email@example.com) Ingperl Ingres Tim Bunce (firstname.lastname@example.org) and Ted Lemon Interperl Interbase Buzz Moschetti (email@example.com) Isqlperl Informix William Hails, firstname.lastname@example.org Oraperl Oracle Kevin Stock (kstock@Auspex.com) Pgperl Postgres Igor Metz (email@example.com) *Sqlperl Ingres Ted Lemon (firstname.lastname@example.org) Sybperl Sybase Michael Peppler (email@example.com) Uniperl Unify 5.0 Rick Wargo (firstname.lastname@example.org)
? Does this one still exist? * Sqlperl appears to have been subsumed by Ingperl
Buzz Moschetti* has organized a project to create a higher level interface to will allow you to write your queries in a database- independent fashion. If this type of project interests you, send mail to <email@example.com> and asked to be placed on the "perldb-interest" mailing lists.
Here's a bit of advertising from Buzz:
Perl is an interpreted language with powerful string, scalar, and array processing features developed by Larry Wall that "nicely bridges the functionality gap between sh(1) and C." Since relational DB operations are typically textually oriented, perl is particularly well-suited to manage the data flows. The C source code, which is available free of charge and runs on many platforms, contains a user-defined function entry point that permits a developer to extend the basic function set of the language. The DBperl Group seeks to exploit this capability by creating a standardized set of perl function extensions (e.g. db_fetch(), db_attach()) based the SQL model for manipulating a relational DB, thus providing a portable perl interface to a variety of popular RDMS engines including Sybase, Oracle, Ingres, Informix, and Interbase. In theory, any DB engine that implements a dynamic SQL interpreter in its HLI can be bolted onto the perl front end with predicatable results, although at this time backends exist only for the aforementioned five DB engines.
The official archive for DBperl extensions is ftp.demon.co.uk: /pub/perl/db. It's the home of the evolving DBperl API Specification. Here's an extract from the updated README there:
DBI/ The home of the DBI archive. To join the DBI mailing list send your request to perldb-interest-REQUEST@vix.com
DBD/ Database Drivers for the DBI ...
Oracle/ By Tim Bunce (not yet ready!) Ingres/ By Tim Bunce (not yet started!)
mod/ Other Perl 5 Modules and Extensions ...
Sybperl/ By Michael Peppler, firstname.lastname@example.org
perl4/ Perl 4 extensions (using the usub C interface)
oraperl/ ORACLE 6 & 7 By Kevin Stock (sadly no longer on the net) sybperl/ SYBASE 4 By Michael Peppler, email@example.com ingperl/ INGRES By Tim Bunce firstname.lastname@example.org and Ted Lemon isqlperl/ INFORMIX By William Hails, email@example.com interperl/ INTERBASE By Buzz Moschetti, firstname.lastname@example.org oraperl/ ORACLE 6 & 7 By Kevin Stock (sadly no longer on the net) sybperl/ SYBASE 4 By Michael Peppler, email@example.com ingperl/ INGRES By Tim Bunce firstname.lastname@example.org and Ted Lemon isqlperl/ INFORMIX By William Hails, email@example.com interperl/ INTERBASE By Buzz Moschetti, firstname.lastname@example.org uniperl/ UNIFY 5.0 By Rick Wargo, email@example.com pgperl/ POSTGRES By Igor Metz, firstname.lastname@example.org
btreeperl/ NDBM perl extensions. By John Conover, email@example.com ctreeperl/ C-Tree perl extensions. By John Conover, firstname.lastname@example.org duaperl/ X.500 Directory User Agent. By Eric Douglas.
scripts/ Perl and shell scripts
rdb/ RDB is a perl RDBMS for ASCII files. By Walt Hobbs, email@example.com shql/ SHQL is an interactive SQL database engine. Written as a shell script, SHQL interprets SQL commands and manipulates flat files based on those commands. By Bruce Momjian, firstname.lastname@example.org xbase/ Perl scripts for accessing xBase style files (dBase III)
refinfo/ Reference information
sqlsyntax/ Yacc and lex syntax and C source code for SQL1 and SQL2 from ftp.uu.net:/pub/uunet/published/oreilly/nutshell/yacclex, and a draft SQL3 syntax from Jeff Fried <email@example.com>+ formats/ Details of file formats such as Lotus 1-2-3 .WK1
There are also a number of non SQL database interfaces for perl available from ftp.demon.co.uk. These include:
Directory Target System Authors and notes --------- ------------- ------------------------------------------- btreeperl NDBM extension John Conover (firstname.lastname@example.org) ctreeperl CTree extension John Conover (email@example.com) duaperl X.500 DUA Eric Douglas rdb RDBMS Walt Hobbs (firstname.lastname@example.org) shql SQL Engine Bruce Momjian (email@example.com)
As shipped, Perl (version 5) comes with interfaces for several DBM packages (SDBM, old DBM, NDBM, GDBM, Berkeley DBM) that are not supplied but either come with your system are readily accessible via FTP. SDBM is guaranteed to be there. For a comparison, see AnyDBM_File(3pm) and DB_File(3pm).
snmperl was written by Guy Streeter (firstname.lastname@example.org), and was posted in late February 1993 to comp.protocols.snmp. It can be found archived at one of two (known) places:
Location: /pub/net/snmp FILE -rw-rw-r-- 3407 Aug 11 1992 snmperl.README FILE -rw-r--r-- 17678 Aug 11 1992 snmperl.tar.Z
Host ftp.cis.ufl.edu Location: /pub/perl/scripts/snmp
Here is the gist of the README:
README $Revision: 2.3 $
This directory contains the source code to add callable C subroutines to perl. The subroutines implement the SNMP functions "get", "getnext", and "set". They use the freely-distributable SNMP package (version 1.1b) from CMU.
USE: There are four subroutines defined in the callable interface: snmp_get, snmp_next, snmp_set, and snmp_error.
snmp_get and snmp_next implement the GET and GETNEXT operations, respectively. The first two calling arguments are the hostname and Community string. The IP address of the host, as a dotted-quad ASCII string, may be used as the hostname. The rest of the calling arguments are a list of variables. See the CMU package documentation for how variables may be specified. snmp_set also takes hostname and Community string as arguments. The remaining arguments are a list of triples consisting of variable name, variable type, and value. The variable type is a string, such as "INTEGER" or "IpAddress". snmp_get, snmp_next, and snmp_set return a list containing alternating variables and values. snmp_get and snmp_next will simply omit non-existent variables on return. snmp_set will fail completely if one of the specified variables does not exist (or is read-only). snmp_error will return a text string containing some error information about the most recent snmp_get|next|set call, if it had an error.
OTHER NOTES: I didn't find all the places where the CMU library writes to stderr or calls exit() directly. The changes I made to mib.c involve the formatting of variable values for return to the caller. I took out the descriptive prefix so the string contains only the value. Enumerated types are returned as a string containing the symbolic representation followed in parentheses by the numeric.
DISTRIBUTION and OWNERSHIP perl and the CMU SNMP package have their own statements. Read them. The work I've done is free and clear. Just don't say you wrote it if you didn't, and don't say I wrote it if you change it.
Guy Streeter email@example.com April 1, 1992 (not a joke!)
Stephen P Potter firstname.lastname@example.org Varimetrix Corporation 2350 Commerce Park Drive, Suite 4 Palm Bay, FL 32905 (407) 676-3222 CAD/CAM/CAE/Software