[22653] in Perl-Users-Digest
Perl-Users Digest, Issue: 4874 Volume: 10
daemon@ATHENA.MIT.EDU (Perl-Users Digest)
Tue Apr 22 06:05:54 2003
Date: Tue, 22 Apr 2003 03:05:05 -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, 22 Apr 2003 Volume: 10 Number: 4874
Today's topics:
Re: Beginners question - directions please... <anthony_w@bigpond.com>
Re: changing the date <Steffen.Beyer@de.bosch.com>
Re: English --> Orkish text filter <no@spam.for.me.invalid>
Re: How can I hide a specific Window <goodcall__1@hotmail.com>
number of elements in an array that is part of a hash (Klaus Kleiner)
Re: number of elements in an array that is part of a ha <bart.lateur@pandora.be>
Re: number of elements in an array that is part of a ha <mbudash@sonic.net>
Re: number of elements in an array that is part of a ha <mbudash@sonic.net>
Posting Guidelines for comp.lang.perl.misc ($Revision: tadmc@augustmail.com
Re: remembering values <tore@aursand.no>
Uninitialized value when run from cron, ok from termina <arthur_vd@gmx.net>
Re: Uninitialized value when run from cron, ok from ter <arthur_vd@gmx.net>
Re: Uninitialized value when run from cron, ok from ter (Anno Siegel)
Re: Uninitialized value when run from cron, ok from ter <arthur_vd@gmx.net>
Digest Administrivia (Last modified: 6 Apr 01) (Perl-Users-Digest Admin)
----------------------------------------------------------------------
Date: Tue, 22 Apr 2003 15:56:03 +1000
From: "Anthony White" <anthony_w@bigpond.com>
Subject: Re: Beginners question - directions please...
Message-Id: <pan.2003.04.22.05.56.03.93744@bigpond.com>
Hi Mark (And others),
Thank you for your assistance. I have tried to understand
what goes on here with Perl Beginners books :-) and some
on-line works at "library.perl.org" but can not get a full
understanding of what is happening.
The script does not do anything when run, the cursor simply
just sits there on the next line (No output).
I have added the file format again at the end of the post with a few
more entries.
Please look again and let me know if there is something I am overlooking.
Tony
Here is what I did to get the data from the "config" file:
#!/usr/bin/perl
use strict;
use warnings;
### My part added...
my $movies = "/opt/FTG/movie_schedule"; # The path in my test setup...
open (MOVIE_SCH, $movies) or die "Can not open: $movies: $!\n";
my @entries = <MOVIE_SCH>;
close(MOVIE_SCH) or die "Can not close: $movies: $!\n"; Play safe :-)
# Using: print @entries; confirms that the file has been
# slurped correctly and is available in the array @entries
# Your array is above...
# my @entries;
### What does this do?
undef $/; # slurp entire file, make sure the file isn't so
# big it takes up all your RAM
### Does this take data line by line and assign it to a scalar?
my $file = <>;
$file =~ s!\s*(\#.*)?$!!mg; # Remove any comments and whitespace
### Will the scalar $file not loose all the info?
### I am a bit lost here...It would seem the program gets
### stuck even before getting here.
while( $file =~ s/
(MON|TUE|WED|THU|FRI|SAT|SUN)\n # The day
(\d+)\n # The device
((\d{1,2}:\d{1,2}\n)+) # The times
((.+[ \t]+\d+\n)+) # The files
//mx )
{
my ($day, $dev, $t, $f) = ( $1, $2, $3, $5 );
# Re-format each file
$f =~ s/\n/, /mg;
# print "($day; $dev; $t; $f)\n";
# Parse each time
while( $t =~ s/
(\d{1,2}:\d{1,2})\n # Each time
//mx )
{
# print "$day $dev $1 ($f)\n";
my @tmp = ($day, $dev, $1, "($f)");
push @entries, \@tmp;
}
}
foreach my $e (@entries){
print join(', ', @$e), "\n";
}
### End of script
>>
>> My biggest problem is that I do not know how to get from the
>> given file format to an array with a suitable format that can be
>> run, something like:
>>
>> MON 0 02:00 (/some/path/file.name_1 1, /some/path/file.name_2 1, etc)
>> MON 1 12:00 (/some/path/file.name1 1, /some/path/file.name_2 1, etc)
>> TUE 0 15:00 (/some/path/file.name1 1, /some/path/file.name_2 1, etc)
>>
>> Maybe this is the wrong approach....
>>
>> It may be better to scan the entire file in a loop matching against the
>> day of the week, then picking up the output device number, then matching
[...snip...]
Begin file format.
======================
MON
0
00:00
04:00
08:00
12:00
16:00
20:00
/movie/trailer.mpg 1
/advert/buy.mpg 1
/movie/movie.mpg 1
/advert/buy.mpg 1
/movie/previews.mpg 0
MON
1
02:00
06:00
10:00
14:00
18:00
22:00
/movie/trailer.mpg 1
/advert/buy.mpg 1
/movie/movie.mpg 1
/advert/buy.mpg 1
/movie/previews.mpg 0
MON
3
01:00
05:00
09:00
13:00
17:00
21:00
/movie/trailer.mpg 1
/advert/buy.mpg 1
/movie/movie.mpg 1
/advert/buy.mpg 1
/movie/previews.mpg 0
MON
4
03:00
07:00
11:00
15:00
19:00
23:00
/movie/trailer.mpg 1
/advert/buy.mpg 1
/movie/movie.mpg 1
/advert/buy.mpg 1
/movie/previews.mpg 0
TUE
0
00:00
04:00
08:00
12:00
16:00
20:00
/movie/trailer.mpg 1
/advert/buy.mpg 1
/movie/movie.mpg 1
/advert/buy.mpg 1
/movie/previews.mpg 0
TUE
1
02:00
06:00
10:00
14:00
[...continues like this for the whole week...]
--
------------------------------------------------------------
A linux user...(No spam mail here please)
------------------------------------------------------------
------------------------------
Date: Tue, 22 Apr 2003 08:22:46 +0200
From: "Steffen Beyer" <Steffen.Beyer@de.bosch.com>
Subject: Re: changing the date
Message-Id: <b82n3n$mnj$1@ns2.fe.internet.bosch.com>
"Mario542" <member17678@dbforums.com> wrote:
> Steffen,
>
> I tried what you said and it worked fine, but How do I take the date
> that was entered in the web form($second) and change it to the @date
> value so it can be changed?
>
> my(@date) = ($second);
>
> my(@tomorrow) = Add_Delta_Days(@date, +1);
>
> Thanks,
> Mario
This depends on whether these seconds are in local time,
GMT, or relative to some uncommon epoch.
If they are in local time or GMT, then the Perl documentation
should inform you about how to convert them into a date.
Something along the lines
($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) =
localtime($seconds);
$year += 1900;
$mon++;
or
($sec,$min,$hour,$mday,$mon,$year,$wday,$yday) =
gmtime($seconds);
$year += 1900;
$mon++;
Instead of using gmtime() and having to tweak the year and month,
you can also use Date::Calc like this:
($year,$month,$day, $hour,$min,$sec) = Time_to_Date($seconds);
In case the seconds are not relative to the standard epoch
of your system (usually 01-Jan-1970 00:00:00 GMT under Unix and
01-Jan-1904 00:00:00 (local time) under MacOS Classic, for example),
use the Time_to_Date() function of Date::Calc and adjust for
the difference between the epoch used by your system and the
epoch your input is relative to.
Either by adding/subtracting the appropriate number of seconds
to/from the input, or by adjusting as follows:
#!perl -w
use strict;
use Date::Calc qw(:all);
my @epoch = (1980,1,1,12,0,0); # or whatever
my @date = Time_to_Date($seconds);
@date = Add_Delta_YMDHMS(@date, Delta_YMDHMS(Time_to_Date(0), @epoch));
printf("%s %02d:%02d:%02d\n", Date_to_Text_Long(@date[0,1,2]), @date[3,4,5]);
Note: It would be more efficient to cache the value for
Delta_YMDHMS(Time_to_Date(0), @epoch)
Hope this helps. :-)
Steffen
------------------------------
Date: Tue, 22 Apr 2003 08:02:07 GMT
From: Nils Petter Vaskinn <no@spam.for.me.invalid>
Subject: Re: English --> Orkish text filter
Message-Id: <pan.2003.04.22.08.55.40.263727.20126@spam.for.me.invalid>
On Fri, 18 Apr 2003 20:04:51 +0200, Arduin wrote:
> Free text filter, written using Perl, that converts english to "orkish":
>
> http://hiddenway.tripod.com/waaagh/orklib.pm.txt
>
> Nothing particularly clever about the source -- it's merely for
> amusement. (Similar to the old Swedish Chef and Elmer Fudd filters.)
>
> Note: Too many access attempts to this site might exceed the download
> limit, so please be gentle. ;-)
>
> Thanks.
>
> --
> Bob
We need numerical conversion:
sub convert_number
{
$_ = shift;
if ($_ == 0) {
return "none";
}
elsif ($_ == 1) {
return "one";
}
elsif ($_ == 2) {
return "two";
}
elsif ($_ < 20) {
return "many";
}
elsif ($_ < 0) {
return "huh? stwange!";
}
else {
return "too many"
}
}
NP
------------------------------
Date: Tue, 22 Apr 2003 06:51:24 GMT
From: "Jack D." <goodcall__1@hotmail.com>
Subject: Re: How can I hide a specific Window
Message-Id: <MD5pa.19263$4P1.1976046@news2.telusplanet.net>
"Thomas B" <thomas@shurflo.com> wrote in message
news:866f534e.0304211550.3bb6e960@posting.google.com...
> I actually want to launch a separate process and hide it.
As Rob stated, you probably want to use Win32::Process for the most control.
However, if your separate process is just a perl script, you could always try
using wperl.exe in your system call.
<snip>
> >
> > This is just an example. I actually want to hide a Perl Script that
> > does background virus update checking. I know how to hide the current
> > running Perl Script - I need to find out how to hide a separate
> > application.
--
Jack D.
Remove '__' from address if replying by e-mail.
------------------------------
Date: 21 Apr 2003 23:17:04 -0700
From: Klaus.Kleiner@gmx.net (Klaus Kleiner)
Subject: number of elements in an array that is part of a hash
Message-Id: <3394ad07.0304212217.687d8e64@posting.google.com>
I know that I could get the number of elements of an array with
$Elements = @Array;
Now I have an array containing a hash containing an arry, loks like:
$Person[$i]{children}[$j]{age} = 5;
($i and $j are just scalar counters
Person No $i has children, child No $j is 5 years old)
Number of persons is no problem:
$Elements = @Person; # OK !
but number of children doesn't work:
$Elements = @Persion[$i]{children}; # ERROR ?
Any help apprecheated
------------------------------
Date: Tue, 22 Apr 2003 06:26:05 GMT
From: Bart Lateur <bart.lateur@pandora.be>
Subject: Re: number of elements in an array that is part of a hash
Message-Id: <7un9avkt3p3vti8i1e0scpfmbpqlve7rpg@4ax.com>
Klaus Kleiner wrote:
>I know that I could get the number of elements of an array with
>$Elements = @Array;
>
>Now I have an array containing a hash containing an arry, loks like:
>$Person[$i]{children}[$j]{age} = 5;
>($i and $j are just scalar counters
>Person No $i has children, child No $j is 5 years old)
>
>
>Number of persons is no problem:
>$Elements = @Person; # OK !
>
>but number of children doesn't work:
>$Elements = @Persion[$i]{children}; # ERROR ?
(type $Persion -> $Person)
$Person[$i]{children} is an array reference. You need to dereference it,
and take the number of elements from that. You dereference an array
reference by preceding it with @:
$Elements = @$arrayref;
but in case of possible precedence problems, you may put the reference
in a block:
$Elements = @{$arrayref};
Very likely this is the case here, so it's safest to do
$Elements = @{$Person[$i]{children}};
which is the answer to your problem.
--
Bart.
------------------------------
Date: Tue, 22 Apr 2003 06:34:54 GMT
From: Michael Budash <mbudash@sonic.net>
Subject: Re: number of elements in an array that is part of a hash
Message-Id: <mbudash-360F06.23345921042003@typhoon.sonic.net>
In article <3394ad07.0304212217.687d8e64@posting.google.com>,
Klaus.Kleiner@gmx.net (Klaus Kleiner) wrote:
> I know that I could get the number of elements of an array with
> $Elements = @Array;
>
> Now I have an array containing a hash containing an array, looks like:
> $Person[$i]{children}[$j]{age} = 5;
> ($i and $j are just scalar counters
> Person No $i has children, child No $j is 5 years old)
>
>
> Number of persons is no problem:
> $Elements = @Person; # OK !
>
> but number of children doesn't work:
> $Elements = @Persion[$i]{children}; # ERROR ?
>
> Any help apprecheated
it actually appears that you have an array containing hashrefs whose
values are arrayrefs whose elements are hashrefs...
$Elements = @{$Person[0]{children}};
hth-
--
Michael Budash
------------------------------
Date: Tue, 22 Apr 2003 06:36:12 GMT
From: Michael Budash <mbudash@sonic.net>
Subject: Re: number of elements in an array that is part of a hash
Message-Id: <mbudash-DBA306.23361721042003@typhoon.sonic.net>
In article <mbudash-360F06.23345921042003@typhoon.sonic.net>,
Michael Budash <mbudash@sonic.net> wrote:
> In article <3394ad07.0304212217.687d8e64@posting.google.com>,
> Klaus.Kleiner@gmx.net (Klaus Kleiner) wrote:
>
> > I know that I could get the number of elements of an array with
> > $Elements = @Array;
> >
> > Now I have an array containing a hash containing an array, looks like:
> > $Person[$i]{children}[$j]{age} = 5;
> > ($i and $j are just scalar counters
> > Person No $i has children, child No $j is 5 years old)
> >
> >
> > Number of persons is no problem:
> > $Elements = @Person; # OK !
> >
> > but number of children doesn't work:
> > $Elements = @Persion[$i]{children}; # ERROR ?
> >
> > Any help apprecheated
>
> it actually appears that you have an array containing hashrefs whose
> values are arrayrefs whose elements are hashrefs...
>
> $Elements = @{$Person[0]{children}};
>
> hth-
oops - copied my answer in from my test... should be:
$Elements = @{$Person[$i]{children}};
hth-
--
Michael Budash
------------------------------
Date: Tue, 22 Apr 2003 01:22:46 -0500
From: tadmc@augustmail.com
Subject: Posting Guidelines for comp.lang.perl.misc ($Revision: 1.4 $)
Message-Id: <F5GdnRBmINwrQjmjXTWcoA@august.net>
Outline
Before posting to comp.lang.perl.misc
Must
- Check the Perl Frequently Asked Questions (FAQ)
- Check the other standard Perl docs (*.pod)
Really Really Should
- Lurk for a while before posting
- Search a Usenet archive
If You Like
- Check Other Resources
Posting to comp.lang.perl.misc
Is there a better place to ask your question?
- Question should be about Perl, not about the application area
How to participate (post) in the clpmisc community
- Carefully choose the contents of your Subject header
- Use an effective followup style
- Speak Perl rather than English, when possible
- Ask perl to help you
- Do not re-type Perl code
- Provide enough information
- Do not provide too much information
- Do not post binaries, HTML, or MIME
Social faux pas to avoid
- Asking a Frequently Asked Question
- Asking a question easily answered by a cursory doc search
- Asking for emailed answers
- Beware of saying "doesn't work"
- Sending a "stealth" Cc copy
Be extra cautious when you get upset
- Count to ten before composing a followup when you are upset
- Count to ten after composing and before posting when you are upset
-----------------------------------------------------------------
Posting Guidelines for comp.lang.perl.misc ($Revision: 1.4 $)
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.
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://mail.augustmail.com/~tadmc/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
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
"Jeopardy" (because the answer comes before the question), or
"TOFU".
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 <tadmc@augustmail.com> and many others on the
comp.lang.perl.misc newsgroup.
------------------------------
Date: Tue, 22 Apr 2003 11:43:32 +0200
From: "Tore Aursand" <tore@aursand.no>
Subject: Re: remembering values
Message-Id: <pan.2003.04.21.10.18.43.814476@aursand.no>
On Fri, 18 Apr 2003 09:19:59 -0700, Chris wrote:
> I have a cgi script that displays a webpage asking the user to click
> option 1 or option 2. [...] I've thought about saving the variable in
> a hidden field but since I'm not using forms this isn't possible.
That's impossible; You _must_ use forms if you're displaying such a web
page you're talking about.
> Cookies may work but I'm reading they have a size limit.
No problem saving the values you're askin for, ie. 'option=1' etc.
> Session variables seems to be the way to go.
It is. Have a look at the CGIS module. It comes with examples.
--
Tore Aursand <tore@aursand.no>
"You know the world is going crazy when the best rapper is white, the best
golfer is black, France is accusing US of arrogance and Germany doesn't
want to go to war."
------------------------------
Date: Tue, 22 Apr 2003 09:34:50 +0200
From: Arthur <arthur_vd@gmx.net>
Subject: Uninitialized value when run from cron, ok from terminal
Message-Id: <3ea4f09b@zinews.unizh.ch>
When I run the script below, everything works fine when running it
manually with the shell. But running it with the cron daemon
( 0-59/5 * * * * /home/user/tempcheck.pl > /dev/null )
gives me the following errors:
Use of uninitialized value in numeric gt (>) at tempcheck.pl line 28.
Use of uninitialized value in numeric gt (>) at tempcheck.pl line 34.
6 times
The output of more /proc/sys/dev/sensors/w83627hf-isa-0290/temp1 && more
/proc/sys/dev/sensors/w83627hf-isa-0290/temp3 is:
60.0 50.0 34.0
60.0 50.0 35.5
I've added a print statement and removed "> /dev/null" from the command
to see where the warnings come from:
from the shell: run by cron:
34.0n n
35.5n n
n
34.0n
n
n
n
35.5n
Somehow there seem to be more lines in @used as before. But why I really
can't see. Any help greatly appreciated.
Arthur
The script:
#!/usr/bin/perl -w
# Sends mail if temperatures are to high
use strict;
my $ALERT_THRESHOLD="40";
my $FIRE_THRESHOLD="80"; # Has to be > $ALERT_THRESHOLD
my $temps="more /proc/sys/dev/sensors/w83627hf-isa-0290/temp1 && more
/proc/sys/dev/sensors/w83627hf-isa-0290/temp3"; # get temperatures
my $send=0;
my $fire_send=0;
my @tomail;
my @tomailz;
my @tempe = `$temps`;
foreach (@tempe)
{
chomp();
@_=split();
print($_[2]."n\n");
if ($_[2] > $ALERT_THRESHOLD)
{
$send = 1;
push @tomail,"$_[2]\n";
push @tomailz,"$_[2]\n";
}
if ($_[2] > $FIRE_THRESHOLD)
{
$fire_send = 1;
}
}
if ($send == 1)
{
# send mail
}
if ($fire_send == 1)
{
# send SMS
}
------------------------------
Date: Tue, 22 Apr 2003 09:53:33 +0200
From: Arthur <arthur_vd@gmx.net>
Subject: Re: Uninitialized value when run from cron, ok from terminal
Message-Id: <3ea4f4fd$1@zinews.unizh.ch>
> Somehow there seem to be more lines in @used as before. But why I really
> can't see.
Oh, that should read "in @tempe as before". Sorry.
------------------------------
Date: 22 Apr 2003 07:53:10 GMT
From: anno4000@lublin.zrz.tu-berlin.de (Anno Siegel)
Subject: Re: Uninitialized value when run from cron, ok from terminal
Message-Id: <b82sd6$du3$1@mamenchi.zrz.TU-Berlin.DE>
Arthur <arthur_vd@gmx.net> wrote in comp.lang.perl.misc:
> When I run the script below, everything works fine when running it
> manually with the shell. But running it with the cron daemon
> ( 0-59/5 * * * * /home/user/tempcheck.pl > /dev/null )
> gives me the following errors:
>
> Use of uninitialized value in numeric gt (>) at tempcheck.pl line 28.
> Use of uninitialized value in numeric gt (>) at tempcheck.pl line 34.
> 6 times
>
> The output of more /proc/sys/dev/sensors/w83627hf-isa-0290/temp1 && more
> /proc/sys/dev/sensors/w83627hf-isa-0290/temp3 is:
>
> 60.0 50.0 34.0
> 60.0 50.0 35.5
>
> I've added a print statement and removed "> /dev/null" from the command
> to see where the warnings come from:
>
> from the shell: run by cron:
> 34.0n n
> 35.5n n
> n
> 34.0n
> n
> n
> n
> 35.5n
>
> Somehow there seem to be more lines in @used as before. But why I really
> can't see. Any help greatly appreciated.
>
> Arthur
>
> The script:
>
> #!/usr/bin/perl -w
> # Sends mail if temperatures are to high
>
> use strict;
>
> my $ALERT_THRESHOLD="40";
> my $FIRE_THRESHOLD="80"; # Has to be > $ALERT_THRESHOLD
> my $temps="more /proc/sys/dev/sensors/w83627hf-isa-0290/temp1 && more
> /proc/sys/dev/sensors/w83627hf-isa-0290/temp3"; # get temperatures
The "more" command is not a suitable tool to read external files.
It is an interactive command, who knows what it does in batch mode
under cron. Open the files (checking for errors), and read them.
If you must use an external command, use "cat".
Anno
------------------------------
Date: Tue, 22 Apr 2003 10:09:26 +0200
From: Arthur <arthur_vd@gmx.net>
Subject: Re: Uninitialized value when run from cron, ok from terminal
Message-Id: <3ea4f8b7@zinews.unizh.ch>
> The "more" command is not a suitable tool to read external files.
> It is an interactive command, who knows what it does in batch mode
> under cron. Open the files (checking for errors), and read them.
> If you must use an external command, use "cat".
Duh. Stupid me. The stepwise refinement approach isn't always the
best... It works flawlessly with cat and I'll probably switch to opening
the file within perl.
Thanks a lot for your help.
Arthur
------------------------------
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:
The Perl-Users Digest is a retransmission of the USENET newsgroup
comp.lang.perl.misc. For subscription or unsubscription requests, send
the single line:
subscribe perl-users
or:
unsubscribe perl-users
to almanac@ruby.oce.orst.edu.
To submit articles to comp.lang.perl.announce, send your article to
clpa@perl.com.
To request back copies (available for a week or so), send your request
to almanac@ruby.oce.orst.edu with the command "send perl-users x.y",
where x is the volume number and y is the issue number.
For other requests pertaining to the digest, send mail to
perl-users-request@ruby.oce.orst.edu. Do not waste your time or mine
sending perl questions to the -request address, I don't have time to
answer them even if I did know the answer.
------------------------------
End of Perl-Users Digest V10 Issue 4874
***************************************
