[29480] in Perl-Users-Digest
Perl-Users Digest, Issue: 724 Volume: 11
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Tue Aug 7 06:10:08 2007
Date: Tue, 7 Aug 2007 03:09:05 -0700 (PDT)
From: Perl-Users Digest <Perl-Users-Request@ruby.OCE.ORST.EDU>
To: Perl-Users@ruby.OCE.ORST.EDU (Perl-Users Digest)
Perl-Users Digest Tue, 7 Aug 2007 Volume: 11 Number: 724
Today's topics:
Re: 'localtime' question <skye.shaw@gmail.com>
CGI. postgres local install, DBD::Pg fails brian.darkblueb@gmail.com
Re: Checking user's in passwd file <news@lawshouse.org>
Re: Checking user's in passwd file <waveright@gmail.com>
Re: Checking user's in passwd file <joe@inwap.com>
Help in file locking and synchronization ramesh.thangamani@gmail.com
Re: Help in file locking and synchronization <skye.shaw@gmail.com>
new CPAN modules on Tue Aug 7 2007 (Randal Schwartz)
Re: Parent Process id. <joe@inwap.com>
Re: Parent Process id. <skye.shaw@gmail.com>
Posting Guidelines for comp.lang.perl.misc ($Revision: tadmc@seesig.invalid
Re: Recompiling perl from scratch <joe@inwap.com>
Re: Replacing a line <tadmc@seesig.invalid>
Re: Replacing a line <vedpsingh@gmail.com>
Select / Case in perl <bill@ts1000.us>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Tue, 07 Aug 2007 08:09:45 -0000
From: "Skye Shaw!@#$" <skye.shaw@gmail.com>
Subject: Re: 'localtime' question
Message-Id: <1186474185.892872.202030@x40g2000prg.googlegroups.com>
On Aug 5, 12:11 pm, "Mr. Shawn H. Corey" <shawnhco...@magma.ca> wrote:
> Pad...@gmail.com wrote:
> > Using Linux the following code :
>
> > use POSIX qw(strftime);
> > my $now = strftime "%Y%m%e", localtime;
>
> > yields '20070805'
>
> > Under Windows the same code yields:
>
> > '200708'
>
> > Any ideas on how to get the day of the month included using Windows?
>
> Strange, both of them should be: 200708 5
strftime(3) says that the %e format flag is part of the Single Unix
Specification.
Maybe %e is possible on Windows, depending on your systems service
packs/installs and the level of POSIX compliance they add.
------------------------------
Date: Mon, 06 Aug 2007 20:25:49 -0700
From: brian.darkblueb@gmail.com
Subject: CGI. postgres local install, DBD::Pg fails
Message-Id: <1186457149.462331.292630@q3g2000prf.googlegroups.com>
DBD::Pg installed fine on a stock OS X machine. Apache is turned on
via web sharing.
When we installed DBD::Pg, it magically 'found' that postgres was
installed in the local (admin) folder instead of /usr/local. All
DBD::Pg test ran as fine.
BUT when code runs as a CGI, the CGI user 'www' apparently cannot
access the postgres libraries. A quick attempt at setting a library's
permissions (libq ?) was no help.
suggestions welcome
------------------------------
Date: Mon, 06 Aug 2007 19:39:56 +0100
From: Henry Law <news@lawshouse.org>
Subject: Re: Checking user's in passwd file
Message-Id: <1186425558.17175.0@damia.uk.clara.net>
Fred wrote:
> I have a list of valid users that I need to cross reference to
> the /etc/passwd files on various systems. So lets suppose the
> (shortened) list of valid users is:
>
>
> John Doe
> Susan Archer
> Monty Python
>
>
> Now let's say there's an entry in the /etc/passwd file for an
> employee named George Smith who has left the company:
>
> gsmith:cXU6Km8JDj:9446:9400:George Smith:/home/gsmith:/bin/bash
>
>
> How would I determine if the George Smith user is invalid?
You should write some Perl which
(1) Reads the valid user names into an array or maybe a hash
(2) Reads in /etc/passwd and parses out the real names, using the ":"
character as the separator; put those in another array.
(3) Compare the names in the array/hash with the names parsed out of
/etc/passwd and do whatever you want when you find, or fail to find, a
match.
But what are you going to do when "George Smith" has a correct passwd
entry with, maybe, "George W Smith"? Or "G Smith"? You have a
specification problem, as well as the problem caused by your total lack
of willingness to attempt a solution to your own assignment before
bothering us with it.
--
Henry Law Manchester, England
------------------------------
Date: Tue, 07 Aug 2007 00:19:36 -0000
From: Todd Wade <waveright@gmail.com>
Subject: Re: Checking user's in passwd file
Message-Id: <1186445976.027997.45740@j4g2000prf.googlegroups.com>
On Aug 5, 10:54 am, Fred <itf...@cdw.com> wrote:
> I have a list of valid users that I need to cross reference to
> the /etc/passwd files on various systems. So lets suppose the
> (shortened) list of valid users is:
>
> John Doe
> Susan Archer
> Monty Python
>
> Now let's say there's an entry in the /etc/passwd file for an
> employee named George Smith who has left the company:
>
> gsmith:cXU6Km8JDj:9446:9400:George Smith:/home/gsmith:/bin/bash
>
> How would I determine if the George Smith user is invalid?
I'd DBD::CSV to treat the passwd file as a database table. I was going
to write up some code for you, but the POD for DBD::CSV already has an
example of doing this exact thing:
http://search.cpan.org/~jzucker/DBD-CSV/
You can find the example near the "Metadata" label:
http://search.cpan.org/~jzucker/DBD-CSV/lib/DBD/CSV.pm#Metadata
trwww
------------------------------
Date: Mon, 06 Aug 2007 22:23:55 -0700
From: Joe Smith <joe@inwap.com>
Subject: Re: Checking user's in passwd file
Message-Id: <p_SdnSiBKPNonCXbnZ2dnUVZ_tyknZ2d@comcast.com>
Fred wrote:
> Now let's say there's an entry in the /etc/passwd file for an
> employee named George Smith who has left the company:
>
> gsmith:cXU6Km8JDj:9446:9400:George Smith:/home/gsmith:/bin/bash
>
> How would I determine if the George Smith user is invalid?
In the example you've provided, I can tell two things:
1) It's an older system, one that still keeps the password hash inside
/etc/passwd instead of /etc/shadow.
2) The account is still active (it does not have ! or # or * as the first
character of the hash value).
An entry like that implies that the account has not been terminated.
Either it is still a valid active account, or you've got a security breach.
-Joe
------------------------------
Date: Mon, 06 Aug 2007 22:57:39 -0700
From: ramesh.thangamani@gmail.com
Subject: Help in file locking and synchronization
Message-Id: <1186466259.995925.177360@g12g2000prg.googlegroups.com>
I am working on a script which queries LDAP for a group of people and
stores the details in XML preserving the hierarchy. I have used a perl
module to create the XML file, the same module can parse it when
needed. I will also have a perl script to create the XML file daily so
that the details in the XML file are in sync with the LDAP details.
Now the problem here is there can be synchronization problem when the
XML is getting generated
by more than one user running the script at the same time. What could
be the best approach for this problem. Any suggestions ?
- I have seen file locking stuff but not sure what needs to be done
to avoid any issues .
- Will be better to have some timeout and wait to write the file ?.
- Or should I skip if the file has already been created like that etc.
------------------------------
Date: Tue, 07 Aug 2007 07:11:52 -0000
From: "Skye Shaw!@#$" <skye.shaw@gmail.com>
Subject: Re: Help in file locking and synchronization
Message-Id: <1186470712.584228.124590@x40g2000prg.googlegroups.com>
On Aug 6, 10:57 pm, ramesh.thangam...@gmail.com wrote:
> I am working on a script which queries LDAP for a group of people and
> stores the details in XML preserving the hierarchy.
<snip>
> Now the problem here is there can be synchronization problem when the
> XML is getting generated
> by more than one user running the script at the same time. What could
> be the best approach for this problem. Any suggestions ?
perldoc -q lock
> - Will be better to have some timeout and wait to write the file ?.
Well flock() will block if another process holds a lock on the given
file. Although the blocking can be indefinite.
> - Or should I skip if the file has already been created like that etc.
You say that the XML file should be /in sync/ with LDAP. Process A
generates the XML, the LDAP structure is changed, then process B
starts. B will pull the most accurate data, so skipping due to the
file created by A would not be in line with your requirements.
You can also avoid any file locking and just have your program attempt
to open a lock file via sysopen and the O_EXCL and O_CREAT flags.
------------------------------
Date: Tue, 7 Aug 2007 04:42:16 GMT
From: merlyn@stonehenge.com (Randal Schwartz)
Subject: new CPAN modules on Tue Aug 7 2007
Message-Id: <JMDzqG.12p7@zorch.sf-bay.org>
The following modules have recently been added to or updated in the
Comprehensive Perl Archive Network (CPAN). You can install them using the
instructions in the 'perlmodinstall' page included with your Perl
distribution.
Amazon-SQS-Simple-0.5
http://search.cpan.org/~swhitaker/Amazon-SQS-Simple-0.5/
OO API for accessing the Amazon Simple Queue Service
----
AppConfig-Exporter-1.04
http://search.cpan.org/~modulo/AppConfig-Exporter-1.04/
Allow modules to import AppConfig sections from a shared configuration.
----
Bio-Grep-v0.8.5
http://search.cpan.org/~limaone/Bio-Grep-v0.8.5/
Perl extension for searching in Fasta files
----
Catalyst-Plugin-Compress-Bzip2-0.03
http://search.cpan.org/~mramberg/Catalyst-Plugin-Compress-Bzip2-0.03/
Bzip2 response
----
Catalyst-Plugin-Compress-Zlib-0.03
http://search.cpan.org/~mramberg/Catalyst-Plugin-Compress-Zlib-0.03/
Zlib Compression for Catalyst
----
Catalyst-Plugin-tv_interval-0.3
http://search.cpan.org/~fayland/Catalyst-Plugin-tv_interval-0.3/
call tv_interval of Time::HiRes to ease profiling.
----
Class-Inspector-1.17
http://search.cpan.org/~adamk/Class-Inspector-1.17/
Get information about a class and its structure
----
Class-Measure-0.03
http://search.cpan.org/~bluefeet/Class-Measure-0.03/
Create, compare, and convert units of measurement.
----
Class-Method-Modifiers-0.03
http://search.cpan.org/~sartak/Class-Method-Modifiers-0.03/
provides Moose-like method modifiers
----
Curses-1.16
http://search.cpan.org/~giraffed/Curses-1.16/
terminal screen handling and optimization
----
Cwd-Ext-1.02
http://search.cpan.org/~leocharre/Cwd-Ext-1.02/
extended file path subroutines
----
DBIx-Class-0.08004
http://search.cpan.org/~mstrout/DBIx-Class-0.08004/
Extensible and flexible object <-> relational mapper.
----
DBIx-Class-Cursor-Cached-1.000000
http://search.cpan.org/~mstrout/DBIx-Class-Cursor-Cached-1.000000/
cursor class with built-in caching support
----
Egg-Release-2.19
http://search.cpan.org/~lushe/Egg-Release-2.19/
Version of Egg WEB Application Framework.
----
HTML-Menu-TreeView-0.7.3
http://search.cpan.org/~lze/HTML-Menu-TreeView-0.7.3/
----
HTTP-OAI-3.19
http://search.cpan.org/~timbrody/HTTP-OAI-3.19/
API for the OAI-PMH
----
IO-AIO-Util-0.02
http://search.cpan.org/~gray/IO-AIO-Util-0.02/
useful functions missing from IO::AIO
----
Logfile-EPrints-1.11
http://search.cpan.org/~timbrody/Logfile-EPrints-1.11/
Parse Apache logs from GNU EPrints
----
Math-Currency-0.4502
http://search.cpan.org/~jpeacock/Math-Currency-0.4502/
Exact Currency Math with Formatting and Rounding
----
MogileFS-Client-1.08
http://search.cpan.org/~bradfitz/MogileFS-Client-1.08/
Client library for the MogileFS distributed file system.
----
MogileFS-Utils-2.12
http://search.cpan.org/~bradfitz/MogileFS-Utils-2.12/
Command line utilities for the MogileFS distributed file system.
----
Net-Google-SafeBrowsing-UpdateRequest-1.06
http://search.cpan.org/~danborn/Net-Google-SafeBrowsing-UpdateRequest-1.06/
Update a Google SafeBrowsing table
----
Net-Ping-2.33
http://search.cpan.org/~smpeters/Net-Ping-2.33/
check a remote host for reachability
----
Net-SSH-Expect-1.03
http://search.cpan.org/~bnegrao/Net-SSH-Expect-1.03/
SSH wrapper to execute remote commands
----
Net-Twitter-1.06
http://search.cpan.org/~cthom/Net-Twitter-1.06/
Perl interface to twitter.com
----
PBS-Client-0.07
http://search.cpan.org/~kwmak/PBS-Client-0.07/
Perl interface to submit jobs to PBS (Portable Batch System)
----
POE-Component-Client-MPD-0.8.0
http://search.cpan.org/~jquelin/POE-Component-Client-MPD-0.8.0/
a full-blown mpd client library
----
Prima-1.22
http://search.cpan.org/~karasik/Prima-1.22/
a perl graphic toolkit
----
Template-Plugin-Num2Word-0.0.2
http://search.cpan.org/~gugod/Template-Plugin-Num2Word-0.0.2/
Convert numbers to words in Template.
----
VFSsimple-0.02
http://search.cpan.org/~nanardon/VFSsimple-0.02/
----
VFSsimple-Drv-File-0.02
http://search.cpan.org/~nanardon/VFSsimple-Drv-File-0.02/
A VFSsimple implementation over real fs
----
VFSsimple-Drv-Ftp-0.02
http://search.cpan.org/~nanardon/VFSsimple-Drv-Ftp-0.02/
A VFSsimple implementation over ftp protocol
----
VFSsimple-Drv-Http-0.02
http://search.cpan.org/~nanardon/VFSsimple-Drv-Http-0.02/
A VFSsimple implementation over http protocol
----
VFSsimple-Drv-Iso-0.02
http://search.cpan.org/~nanardon/VFSsimple-Drv-Iso-0.02/
A VFSsimple implementation over ISO9660 fs
----
VFSsimple-Drv-Rsync-0.02
http://search.cpan.org/~nanardon/VFSsimple-Drv-Rsync-0.02/
A VFSsimple implementation over rsync protocol
----
XML-LibXML-Iterator-1.03
http://search.cpan.org/~phish/XML-LibXML-Iterator-1.03/
XML::LibXML's Tree Iteration Class
----
XML-TreePP-0.24
http://search.cpan.org/~kawasaki/XML-TreePP-0.24/
Pure Perl implementation for parsing/writing xml files
----
XML-TreePP-0.25
http://search.cpan.org/~kawasaki/XML-TreePP-0.25/
Pure Perl implementation for parsing/writing xml files
----
XML-TreePP-0.26
http://search.cpan.org/~kawasaki/XML-TreePP-0.26/
Pure Perl implementation for parsing/writing xml files
If you're an author of one of these modules, please submit a detailed
announcement to comp.lang.perl.announce, and we'll pass it along.
This message was generated by a Perl program described in my Linux
Magazine column, which can be found on-line (along with more than
200 other freely available past column articles) at
http://www.stonehenge.com/merlyn/LinuxMag/col82.html
print "Just another Perl hacker," # the original
--
Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095
<merlyn@stonehenge.com> <URL:http://www.stonehenge.com/merlyn/>
Perl/Unix/security consulting, Technical writing, Comedy, etc. etc.
See PerlTraining.Stonehenge.com for onsite and open-enrollment Perl training!
------------------------------
Date: Mon, 06 Aug 2007 22:14:05 -0700
From: Joe Smith <joe@inwap.com>
Subject: Re: Parent Process id.
Message-Id: <HoadnV341as7YirbnZ2dnUVZ_rXinZ2d@comcast.com>
rajendra wrote:
> Is getppid () is only for UNIX platform?...
On a Windows machine, the answer is "yes and no".
wiggin% uname -a; perl -le 'print getppid()'
CYGWIN_NT-6.0 wiggin 1.5.24(0.156/4/2) 2007-01-31 10:57 i686 Cygwin
6092
C:\Users\jms>perl -le "print getppid()"
The getppid function is unimplemented at -e line 1.
-Joe
------------------------------
Date: Tue, 07 Aug 2007 07:44:11 -0000
From: "Skye Shaw!@#$" <skye.shaw@gmail.com>
Subject: Re: Parent Process id.
Message-Id: <1186472651.141874.52000@q3g2000prf.googlegroups.com>
On Aug 6, 7:56 am, Paul Lalli <mri...@gmail.com> wrote:
> On Aug 6, 10:44 am, "rajendra" <rajendra.pra...@in.bosch.com> wrote:
>
> > Is getppid () is only for UNIX platform?...
>
> perldoc perlport
> NAME
> perlport - Writing portable Perl
> ...
> Alphabetical Listing of Perl Functions
> ...
> getppid Not implemented. (Mac OS, Win32, RISC OS)
>
There's always (gulp), Win32::API.
------------------------------
Date: Tue, 07 Aug 2007 07:11:14 GMT
From: tadmc@seesig.invalid
Subject: Posting Guidelines for comp.lang.perl.misc ($Revision: 1.8 $)
Message-Id: <mWUti.1830$qa3.1084@nlpi069.nbdc.sbc.com>
Outline
Before posting to comp.lang.perl.misc
Must
- Check the Perl Frequently Asked Questions (FAQ)
- Check the other standard Perl docs (*.pod)
Really Really Should
- Lurk for a while before posting
- Search a Usenet archive
If You Like
- Check Other Resources
Posting to comp.lang.perl.misc
Is there a better place to ask your question?
- Question should be about Perl, not about the application area
How to participate (post) in the clpmisc community
- Carefully choose the contents of your Subject header
- Use an effective followup style
- Speak Perl rather than English, when possible
- Ask perl to help you
- Do not re-type Perl code
- Provide enough information
- Do not provide too much information
- Do not post binaries, HTML, or MIME
Social faux pas to avoid
- Asking a Frequently Asked Question
- Asking a question easily answered by a cursory doc search
- Asking for emailed answers
- Beware of saying "doesn't work"
- Sending a "stealth" Cc copy
Be extra cautious when you get upset
- Count to ten before composing a followup when you are upset
- Count to ten after composing and before posting when you are upset
-----------------------------------------------------------------
Posting Guidelines for comp.lang.perl.misc ($Revision: 1.8 $)
This newsgroup, commonly called clpmisc, is a technical newsgroup
intended to be used for discussion of Perl related issues (except job
postings), whether it be comments or questions.
As you would expect, clpmisc discussions are usually very technical in
nature and there are conventions for conduct in technical newsgroups
going somewhat beyond those in non-technical newsgroups.
The article at:
http://www.catb.org/~esr/faqs/smart-questions.html
describes how to get answers from technical people in general.
This article describes things that you should, and should not, do to
increase your chances of getting an answer to your Perl question. It is
available in POD, HTML and plain text formats at:
http://www.rehabitation.com/clpmisc.shtml
For more information about netiquette in general, see the "Netiquette
Guidelines" at:
http://andrew2.andrew.cmu.edu/rfc/rfc1855.html
A note to newsgroup "regulars":
Do not use these guidelines as a "license to flame" or other
meanness. It is possible that a poster is unaware of things
discussed here. Give them the benefit of the doubt, and just
help them learn how to post, rather than assume that they do
know and are being the "bad kind" of Lazy.
A note about technical terms used here:
In this document, we use words like "must" and "should" as
they're used in technical conversation (such as you will
encounter in this newsgroup). When we say that you *must* do
something, we mean that if you don't do that something, then
it's unlikely that you will benefit much from this group.
We're not bossing you around; we're making the point without
lots of words.
Do *NOT* send email to the maintainer of these guidelines. It will be
discarded unread. The guidelines belong to the newsgroup so all
discussion should appear in the newsgroup. I am just the secretary that
writes down the consensus of the group.
Before posting to comp.lang.perl.misc
Must
This section describes things that you *must* do before posting to
clpmisc, in order to maximize your chances of getting meaningful replies
to your inquiry and to avoid getting flamed for being lazy and trying to
have others do your work.
The perl distribution includes documentation that is copied to your hard
drive when you install perl. Also installed is a program for looking
things up in that (and other) documentation named 'perldoc'.
You should either find out where the docs got installed on your system,
or use perldoc to find them for you. Type "perldoc perldoc" to learn how
to use perldoc itself. Type "perldoc perl" to start reading Perl's
standard documentation.
Check the Perl Frequently Asked Questions (FAQ)
Checking the FAQ before posting is required in Big 8 newsgroups in
general, there is nothing clpmisc-specific about this requirement.
You are expected to do this in nearly all newsgroups.
You can use the "-q" switch with perldoc to do a word search of the
questions in the Perl FAQs.
Check the other standard Perl docs (*.pod)
The perl distribution comes with much more documentation than is
available for most other newsgroups, so in clpmisc you should also
see if you can find an answer in the other (non-FAQ) standard docs
before posting.
It is *not* required, or even expected, that you actually *read* all of
Perl's standard docs, only that you spend a few minutes searching them
before posting.
Try doing a word-search in the standard docs for some words/phrases
taken from your problem statement or from your very carefully worded
"Subject:" header.
Really Really Should
This section describes things that you *really should* do before posting
to clpmisc.
Lurk for a while before posting
This is very important and expected in all newsgroups. Lurking means
to monitor a newsgroup for a period to become familiar with local
customs. Each newsgroup has specific customs and rituals. Knowing
these before you participate will help avoid embarrassing social
situations. Consider yourself to be a foreigner at first!
Search a Usenet archive
There are tens of thousands of Perl programmers. It is very likely
that your question has already been asked (and answered). See if you
can find where it has already been answered.
One such searchable archive is:
http://groups.google.com/advanced_group_search
If You Like
This section describes things that you *can* do before posting to
clpmisc.
Check Other Resources
You may want to check in books or on web sites to see if you can
find the answer to your question.
But you need to consider the source of such information: there are a
lot of very poor Perl books and web sites, and several good ones
too, of course.
Posting to comp.lang.perl.misc
There can be 200 messages in clpmisc in a single day. Nobody is going to
read every article. They must decide somehow which articles they are
going to read, and which they will skip.
Your post is in competition with 199 other posts. You need to "win"
before a person who can help you will even read your question.
These sections describe how you can help keep your article from being
one of the "skipped" ones.
Is there a better place to ask your question?
Question should be about Perl, not about the application area
It can be difficult to separate out where your problem really is,
but you should make a conscious effort to post to the most
applicable newsgroup. That is, after all, where you are the most
likely to find the people who know how to answer your question.
Being able to "partition" a problem is an essential skill for
effectively troubleshooting programming problems. If you don't get
that right, you end up looking for answers in the wrong places.
It should be understood that you may not know that the root of your
problem is not Perl-related (the two most frequent ones are CGI and
Operating System related), so off-topic postings will happen from
time to time. Be gracious when someone helps you find a better place
to ask your question by pointing you to a more applicable newsgroup.
How to participate (post) in the clpmisc community
Carefully choose the contents of your Subject header
You have 40 precious characters of Subject to win out and be one of
the posts that gets read. Don't waste them. Take care while
composing them, they are the key that opens the door to getting an
answer.
Spend them indicating what aspect of Perl others will find if they
should decide to read your article.
Do not spend them indicating "experience level" (guru, newbie...).
Do not spend them pleading (please read, urgent, help!...).
Do not spend them on non-Subjects (Perl question, one-word
Subject...)
For more information on choosing a Subject see "Choosing Good
Subject Lines":
http://www.cpan.org/authors/id/D/DM/DMR/subjects.post
Part of the beauty of newsgroup dynamics, is that you can contribute
to the community with your very first post! If your choice of
Subject leads a fellow Perler to find the thread you are starting,
then even asking a question helps us all.
Use an effective followup style
When composing a followup, quote only enough text to establish the
context for the comments that you will add. Always indicate who
wrote the quoted material. Never quote an entire article. Never
quote a .signature (unless that is what you are commenting on).
Intersperse your comments *following* each section of quoted text to
which they relate. Unappreciated followup styles are referred to as
"top-posting", "Jeopardy" (because the answer comes before the
question), or "TOFU" (Text Over, Fullquote Under).
Reversing the chronology of the dialog makes it much harder to
understand (some folks won't even read it if written in that style).
For more information on quoting style, see:
http://web.presby.edu/~nnqadmin/nnq/nquote.html
Speak Perl rather than English, when possible
Perl is much more precise than natural language. Saying it in Perl
instead will avoid misunderstanding your question or problem.
Do not say: I have variable with "foo\tbar" in it.
Instead say: I have $var = "foo\tbar", or I have $var = 'foo\tbar',
or I have $var = <DATA> (and show the data line).
Ask perl to help you
You can ask perl itself to help you find common programming mistakes
by doing two things: enable warnings (perldoc warnings) and enable
"strict"ures (perldoc strict).
You should not bother the hundreds/thousands of readers of the
newsgroup without first seeing if a machine can help you find your
problem. It is demeaning to be asked to do the work of a machine. It
will annoy the readers of your article.
You can look up any of the messages that perl might issue to find
out what the message means and how to resolve the potential mistake
(perldoc perldiag). If you would like perl to look them up for you,
you can put "use diagnostics;" near the top of your program.
Do not re-type Perl code
Use copy/paste or your editor's "import" function rather than
attempting to type in your code. If you make a typo you will get
followups about your typos instead of about the question you are
trying to get answered.
Provide enough information
If you do the things in this item, you will have an Extremely Good
chance of getting people to try and help you with your problem!
These features are a really big bonus toward your question winning
out over all of the other posts that you are competing with.
First make a short (less than 20-30 lines) and *complete* program
that illustrates the problem you are having. People should be able
to run your program by copy/pasting the code from your article. (You
will find that doing this step very often reveals your problem
directly. Leading to an answer much more quickly and reliably than
posting to Usenet.)
Describe *precisely* the input to your program. Also provide example
input data for your program. If you need to show file input, use the
__DATA__ token (perldata.pod) to provide the file contents inside of
your Perl program.
Show the output (including the verbatim text of any messages) of
your program.
Describe how you want the output to be different from what you are
getting.
If you have no idea at all of how to code up your situation, be sure
to at least describe the 2 things that you *do* know: input and
desired output.
Do not provide too much information
Do not just post your entire program for debugging. Most especially
do not post someone *else's* entire program.
Do not post binaries, HTML, or MIME
clpmisc is a text only newsgroup. If you have images or binaries
that explain your question, put them in a publically accessible
place (like a Web server) and provide a pointer to that location. If
you include code, cut and paste it directly in the message body.
Don't attach anything to the message. Don't post vcards or HTML.
Many people (and even some Usenet servers) will automatically filter
out such messages. Many people will not be able to easily read your
post. Plain text is something everyone can read.
Social faux pas to avoid
The first two below are symptoms of lots of FAQ asking here in clpmisc.
It happens so often that folks will assume that it is happening yet
again. If you have looked but not found, or found but didn't understand
the docs, say so in your article.
Asking a Frequently Asked Question
It should be understood that you may have missed the applicable FAQ
when you checked, which is not a big deal. But if the Frequently
Asked Question is worded similar to your question, folks will assume
that you did not look at all. Don't become indignant at pointers to
the FAQ, particularly if it solves your problem.
Asking a question easily answered by a cursory doc search
If folks think you have not even tried the obvious step of reading
the docs applicable to your problem, they are likely to become
annoyed.
If you are flamed for not checking when you *did* check, then just
shrug it off (and take the answer that you got).
Asking for emailed answers
Emailed answers benefit one person. Posted answers benefit the
entire community. If folks can take the time to answer your
question, then you can take the time to go get the answer in the
same place where you asked the question.
It is OK to ask for a *copy* of the answer to be emailed, but many
will ignore such requests anyway. If you munge your address, you
should never expect (or ask) to get email in response to a Usenet
post.
Ask the question here, get the answer here (maybe).
Beware of saying "doesn't work"
This is a "red flag" phrase. If you find yourself writing that,
pause and see if you can't describe what is not working without
saying "doesn't work". That is, describe how it is not what you
want.
Sending a "stealth" Cc copy
A "stealth Cc" is when you both email and post a reply without
indicating *in the body* that you are doing so.
Be extra cautious when you get upset
Count to ten before composing a followup when you are upset
This is recommended in all Usenet newsgroups. Here in clpmisc, most
flaming sub-threads are not about any feature of Perl at all! They
are most often for what was seen as a breach of netiquette. If you
have lurked for a bit, then you will know what is expected and won't
make such posts in the first place.
But if you get upset, wait a while before writing your followup. I
recommend waiting at least 30 minutes.
Count to ten after composing and before posting when you are upset
After you have written your followup, wait *another* 30 minutes
before committing yourself by posting it. You cannot take it back
once it has been said.
AUTHOR
Tad McClellan and many others on the comp.lang.perl.misc newsgroup.
--
Tad McClellan
email: perl -le "print scalar reverse qq/moc.noitatibaher\100cmdat/"
------------------------------
Date: Mon, 06 Aug 2007 22:42:32 -0700
From: Joe Smith <joe@inwap.com>
Subject: Re: Recompiling perl from scratch
Message-Id: <G9CdnVIhF_vImyXbnZ2dnUVZ_uiknZ2d@comcast.com>
dn.perl@gmail.com wrote:
> 1) Should I have installed gcc first before installing perl ?
> I had installed Perl 5.8.5 first, and then gcc.
Order doesn't matter if you're going to build from scratch.
> 2) How do I uninstall perl 5.8.5 and then re-install it 'from
> scratch'?
Use 'pkgrm' to remove the package, then compile the sources.
solaris% wget http://www.cpan.org/src/stable.tar.gz
solaris% mkdir src; cd src
solaris% gunzip -c ../stable.tar.gz | tar xf -
solaris% cd perl-5.8.8
solaris% more README; more README.solaris; more INSTALL
solaris% ./Configure -d
solaris% make && make test
solaris% su -c 'make install'
-Joe
------------------------------
Date: Mon, 06 Aug 2007 22:31:58 GMT
From: Tad McClellan <tadmc@seesig.invalid>
Subject: Re: Replacing a line
Message-Id: <slrnfbf87i.rjb.tadmc@tadmc30.sbcglobal.net>
Ved <vedpsingh@gmail.com> wrote:
> //#define (FileName)FileLoadInput 1
> is to be replaced with
> #define (FileName)FileLoadInput 1
> 1) Remove trailing .cpp in $dir ?
$dir =~ s/\.cpp$//;
> 2) What to do in this to get (/ //#define $dirFileLoadInput 1 /) in
> the for loop ?
> if (/\//#define $dirFileLoadInput 1/) #what to do here ??
s!//(#define ${dir}FileLoadInput 1)!$1!;
--
Tad McClellan
email: perl -le "print scalar reverse qq/moc.noitatibaher\100cmdat/"
------------------------------
Date: Tue, 07 Aug 2007 09:32:16 -0000
From: Ved <vedpsingh@gmail.com>
Subject: Re: Replacing a line
Message-Id: <1186479136.715681.10650@m37g2000prh.googlegroups.com>
Thanks for replies,
Below is the code I have modified now.
$module_name and $cpp_file are coming perfectly fine.
But, I am not able to see this:
print "Finally I am here \n";
It means that "if" condition is not being fuifilled.
if( m{^//#define \$module_nameFileLoadInput $} )
^
|
Is something missing at (this place)
i.e. after $module_name in the if condtion ?
Regards
Ved
#####################################################
#!/usr/local/bin/perl
use strict;
use warnings;
use Tie::File;
my $cpp_file_list = 'my.rxfiles';
open my $fh,'<',$cpp_file_list or die "Cannot read $cpp_file_list:
$!\n";
while (my $cpp_file = <$fh>) {
chop $cpp_file;
my $module_name = "$cpp_file";
$module_name =~ s/\.cpp$//;#removing trainling .cpp
print "this is name $module_name\n";
print "this is CPP $cpp_file\n";
chomp $module_name;#added
if (-e $cpp_file) {
process_one_file($cpp_file);
} else {
warn "File $cpp_file does not exist; skipping\n";
}
}
#Using core module Tie::File to process a file in this subroutine
sub process_one_file {
my $cpp_file = shift;
print "Processing $cpp_file\n";
tie my @array, 'Tie::File', $cpp_file or die "tie error
$cpp_file: $!\n" ;
for (@array)
{
print "I am at this place \n";
# Need to escape the $
if( m{^//#define \$module_nameFileLoadInput $} )
#if( s!//(#define ${module_name}FileLoadInput 1)!$1!)
{
print "Finally I am here \n";
s{^//}{};
# last;
}
}
}
------------------------------
Date: Tue, 07 Aug 2007 03:08:21 -0700
From: Bill H <bill@ts1000.us>
Subject: Select / Case in perl
Message-Id: <1186481301.923958.283680@w3g2000hsg.googlegroups.com>
I did a search of the group and found many messages about a select /
case function in Perl and found references to perldoc -f case and
perldoc -f switch - but neither of these are found under activestate
v5.8's perldoc. Can someone point me to some reference on how to
simulate this structure in perl so I dont have to use endless if's?
Bill H
------------------------------
Date: 6 Apr 2001 21:33:47 GMT (Last modified)
From: Perl-Users-Request@ruby.oce.orst.edu (Perl-Users-Digest Admin)
Subject: Digest Administrivia (Last modified: 6 Apr 01)
Message-Id: <null>
Administrivia:
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------------------------------
End of Perl-Users Digest V11 Issue 724
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