error printing page using LWP::Simple

L

Larry Gates

use strict;
use warnings;
use LWP::Simple;

# load the complete content of the url in question
# via LWP::Simple::get(...)

my $t = get 'http://www.fourmilab.ch/cgi-bin/
Yoursky?z=1&lat=35.0836&ns=North&lon=106.651&ew=West';

print "t is $t";

# perl scraper2.pl

C:\MinGW\source>perl scraper2.pl
Use of uninitialized value in concatenation (.) or string at scraper2.pl
line 14
..
t is
C:\MinGW\source>

I would have expected $t to have the whole page. What gives?
 
L

Larry Gates

Larry said:
# use strict;

Why?

That's an example of me trying things to make it work, and as I run
out of
guesses, the thing I post is the ugliest version I had.:-( This is a
proper post:

C:\MinGW\source>perl scraper2.pl
Use of uninitialized value in concatenation (.) or string at
scraper2.pl line 12
.
t is
C:\MinGW\source>type scraper2.pl
use strict;
use warnings;
use LWP::Simple;

# load the complete content of the url in question
# via LWP::Simple::get(...)

my $t = get 'http://www.fourmilab.ch/cgi-
bin/
Yoursky?z=1&lat=35.0836&ns=North&lon=106.651&ew=West';
# this is line 11
print "t is $t";
# perl scraper2.pl

C:\MinGW\source>]

Is it not a problem that the url is folded over with newlines?


I assumed the new lines were due to you posting with your news client
wrapping the text? Anyway, as I mentioned before, assign a value to
the variable before you try and assign the data from get().

I.e.,

my $t = 'Something went wrong!';
$t = get 'http://domain-and-url-here';
print "t is $t\n";

Have you tried this yet? Is your example domain and URL actually
wrapping in your script, or just when you post it here?

I think I've got a bead on it now:


use warnings;
use LWP::Simple;

# load the complete content of the url in question
# via LWP::Simple::get(...)

my $t = 'Something went right!';
print "t is $t\n"; use strict;

$t = get 'http://domain-and-url-here';
print "t is $t\n"; use strict;

$t = get 'http://www.fourmilab.ch/cgi-
bin/
Yoursky?z=1&lat=35.0836&ns=North&lon=106.651&ew=West';
# this is line 11
print "t is $t";
# perl scraper3.pl
# end script begin output

C:\MinGW\source>perl scraper3.pl
t is Something went right!
Use of uninitialized value in concatenation (.) or string at scraper3.pl
line 12
..
t is
Use of uninitialized value in concatenation (.) or string at scraper3.pl
line 18
..
t is
C:\MinGW\source>

#end output begin comment

I get the same error with your site as I did. Given that Gunnar has said
that I might be asking a site for more information than it elects, in its
kindness, to give me, I'll switch sites and see how that fares.

Thanks and cheers,
--
larry gates

I'm reminded of the day my daughter came in, looked over my shoulder at
some Perl 4 code, and said, "What is that, swearing?"
-- Larry Wall in <[email protected]>
 
T

Tim Greer

Larry said:
Larry said:
On Thu, 05 Feb 2009 07:43:31 -0600, Chris Mattern wrote:


# use strict;

Why?

That's an example of me trying things to make it work, and as I run
out of
guesses, the thing I post is the ugliest version I had.:-( This is
a proper post:

C:\MinGW\source>perl scraper2.pl
Use of uninitialized value in concatenation (.) or string at
scraper2.pl line 12
.
t is
C:\MinGW\source>type scraper2.pl
use strict;
use warnings;
use LWP::Simple;

# load the complete content of the url in question
# via LWP::Simple::get(...)

my $t = get 'http://www.fourmilab.ch/cgi-
bin/
Yoursky?z=1&lat=35.0836&ns=North&lon=106.651&ew=West';
# this is line 11
print "t is $t";
# perl scraper2.pl

C:\MinGW\source>]

Is it not a problem that the url is folded over with newlines?


I assumed the new lines were due to you posting with your news client
wrapping the text? Anyway, as I mentioned before, assign a value to
the variable before you try and assign the data from get().

I.e.,

my $t = 'Something went wrong!';
$t = get 'http://domain-and-url-here';
print "t is $t\n";

Have you tried this yet? Is your example domain and URL actually
wrapping in your script, or just when you post it here?

I think I've got a bead on it now:


use warnings;
use LWP::Simple;

# load the complete content of the url in question
# via LWP::Simple::get(...)

my $t = 'Something went right!';
print "t is $t\n"; use strict;

$t = get 'http://domain-and-url-here';
print "t is $t\n"; use strict;

$t = get 'http://www.fourmilab.ch/cgi-
bin/
Yoursky?z=1&lat=35.0836&ns=North&lon=106.651&ew=West';
# this is line 11
print "t is $t";
# perl scraper3.pl
# end script begin output

C:\MinGW\source>perl scraper3.pl
t is Something went right!
Use of uninitialized value in concatenation (.) or string at
scraper3.pl line 12
.
t is
Use of uninitialized value in concatenation (.) or string at
scraper3.pl line 18
.
t is
C:\MinGW\source>

#end output begin comment

I get the same error with your site as I did. Given that Gunnar has
said that I might be asking a site for more information than it
elects, in its kindness, to give me, I'll switch sites and see how
that fares.

Thanks and cheers,

I've not used this, but neither $t = 'value'; $t = get $url; NOR $t =
get $url or "value" will work (you'll just get different errors). See
my follow up from earlier; You'll need to use $t = (get $url or
"value"); instead -- that does work after trying.

For example (saving word wrap):

my $site_url = 'http://www.fourmilab.ch/cgi-bin/Yoursky';
my $url_args = "z=1&lat=35.0836&ns=North&lon=106.651&ew=West';
my $t = (get "$site_url?$url_args" or "Problem");
print "t is $t\n";

Try that.
 
L

Larry Gates

Larry Gates wrote:

[considering another route]
I've not used this, but neither $t = 'value'; $t = get $url; NOR $t =
get $url or "value" will work (you'll just get different errors). See
my follow up from earlier; You'll need to use $t = (get $url or
"value"); instead -- that does work after trying.

For example (saving word wrap):

my $site_url = 'http://www.fourmilab.ch/cgi-bin/Yoursky';
my $url_args = "z=1&lat=35.0836&ns=North&lon=106.651&ew=West';
my $t = (get "$site_url?$url_args" or "Problem");
print "t is $t\n";

Try that.

That's looking sexy, Tim, I'll take a look when real life doesn't involver
sexy susan. Peace,
--
larry gates

Well, enough clowning around. Perl is, in intent, a cleaned up and
summarized version of that wonderful semi-natural language known as
"Unix".
-- Larry Wall in <[email protected]>
 
T

Tim Greer

Larry said:
Larry Gates wrote:

[considering another route]
I've not used this, but neither $t = 'value'; $t = get $url; NOR $t =
get $url or "value" will work (you'll just get different errors).
See my follow up from earlier; You'll need to use $t = (get $url or
"value"); instead -- that does work after trying.

For example (saving word wrap):

my $site_url = 'http://www.fourmilab.ch/cgi-bin/Yoursky';
my $url_args = "z=1&lat=35.0836&ns=North&lon=106.651&ew=West';
my $t = (get "$site_url?$url_args" or "Problem");
print "t is $t\n";

Try that.

That's looking sexy, Tim, I'll take a look when real life doesn't
involver
sexy susan. Peace,

You can also use:

my $t = get $url || "There was a problem";

An alternative without the parenthesis. I just gave that in reply to
the other suggestion someone made (you'd need to use them with a
literal "or", so that's the same thing). I'd write it as I did just
now above, with ||, personally (instead of using "or").
 
P

Peter Makholm

Tim Greer said:
This is why I suggested defining it and assigning a value first ($t =
"Someting went wrong!", so if it fails, it will show that, but I think
both methods would fail, actually.

I read this like you proposing to write something like this:

my $t = "Something is wrong";
$t = get("http://example.com/");

This would still leave $t with the value undef if the get request
failed and would still give the 'uninitialized variable' warning when
$t is used.

But

my $t = get("http://example.com/)
or "Fail!";

works correctly as you (and others) has suggested.

//Makholm
 
G

Gunnar Hjalmarsson

Works? Well, sort of. It assigns "value" to $t if $url does not contain
a true value, but if $url contains a true value, it does not tell
whether the get() function succeeds or why it fails.
You can also use:

my $t = get $url || "There was a problem";

Same objection.
 
P

Peter Makholm

Gunnar Hjalmarsson said:
Works? Well, sort of. It assigns "value" to $t if $url does not
contain a true value, but if $url contains a true value, it does not
tell whether the get() function succeeds or why it fails.

Corrent. If the content of the url happens to be "" or "0" this
fails. You have to use the defined-or operator. This still don't allow
you to find out *why* get() failed, but this is becaus get() is a
simple interface that wont tell you that.

my $t = get($url) // "Fail!";

Uhmmm, we don't have a low precedence version of '//'?

//Makholm
 
T

Tad J McClellan

Commenting out "use strict" is COUNTER to making things work, as
its proper use helps to find bugs.

The correct approach is to understand and correct the messages
that "use strict" generates.

This can most often be accomplished by adding 3 characters, "my ",
in front of the first use of every variable in the program.



Yes, that is absolutely a problem. So fix it.

use warnings;
use LWP::Simple;

# load the complete content of the url in question
# via LWP::Simple::get(...)

my $t = 'Something went right!';
print "t is $t\n"; use strict;

$t = get 'http://domain-and-url-here';
print "t is $t\n"; use strict;


"use strict" is a compile-time directive, so it happens *before*
the print happens.

It will only be included once, so invoking it more than once
does not do anything at all.

The proper place for a single invocation of "use strict" is up near
the top of your program along with "use warnings".

If you wonder what "use strict" does, you can read its documentation with:

perldoc strict

I get the same error with your site as I did.


If you call get() with a bad URL it will not work.

If get's arg has newlines that are not supposed to be there, it will fail.

If get's arg is a non-existant resource, it will fail.

What does your web browser do when you paste "http://domain-and-url-here"
into its location bar?

It is *supposed* to fail, so it does.
 
D

Dave Weaver

I read this like you proposing to write something like this:

my $t = "Something is wrong";
$t = get("http://example.com/");

This would still leave $t with the value undef if the get request
failed and would still give the 'uninitialized variable' warning when
$t is used.

But

my $t = get("http://example.com/)
or "Fail!";

works correctly as you (and others) has suggested.

You have a problem there - "or" has lower precedence than "=".

ITYM:

my $t = get("http://example.com/)
|| "Fail!";

or
my $t = get("http://example.com/)
or print "Fail!";
 
T

Tim Greer

Peter said:
I read this like you proposing to write something like this:

my $t = "Something is wrong";
$t = get("http://example.com/");

I replied a few minutes after saying he's need to either:

my $t = get("http://example.com/" or "Something is wrong");

Or, better IMO:

my $t = get "http://example.com/" || "Something is wrong";
This would still leave $t with the value undef if the get request
failed and would still give the 'uninitialized variable' warning when
$t is used.

Yes, that is true.
But

my $t = get("http://example.com/)
or "Fail!";

works correctly as you (and others) has suggested.

That works, too. :)
 
T

Tim Greer

Gunnar said:
Works? Well, sort of. It assigns "value" to $t if $url does not
contain a true value, but if $url contains a true value,

That was in reply to someone that suggested get $url or "error", which
wouldn't work unless you put parenthesis. That's why I said "If you
use that, you could do this..."

my $t = get ($url) or "error"; would make more sense.
it does not
tell whether the get() function succeeds or why it fails.
Right.


Same objection.

True.
 
T

Tim Greer

Gunnar said:
Same objection.

By the way, I'm not familiar with this module and function, simply
because I've not used it before myself (I use other solutions), but I'm
curious what the objection above is? As in, I realize it doesn't say
why it failed, but I didn't see any method to have it report the
failure... I mean, since it just returns undefined if there's a
failure.
 
L

Larry Gates

my $site_url = 'http://www.fourmilab.ch/cgi-bin/Yoursky';
my $url_args = "z=1&lat=35.0836&ns=North&lon=106.651&ew=West';
my $t = (get "$site_url?$url_args" or "Problem");
print "t is $t\n";

Big pimpin, Tim.

use strict;
use warnings;
use LWP::Simple;

# load the complete content of the url in question
# via LWP::Simple::get(...)

my $site_url = 'http://www.fourmilab.ch/cgi-bin/Yoursky';
my $url_args = 'z=1&lat=35.0836&ns=North&lon=106.651&ew=West';

my $t = 'Something went right!';
print "t is $t\n";

$t = (get "$site_url?$url_args" or "Problem");


print "t is $t\n";


# perl scraper3.pl

#end script show target

<td>
<input type="text" name="jd" value="2454869.37545" size="20"

How do I grab the julian date from this? Full page listing after sig.
--
larry gates

Just put in another goto, and then it'll be readable. :)
-- Larry Wall in <[email protected]>

<area shape="rect" coords="470,20,545,95" alt="38.5566,213.285"
href="/cgi-bin/Y
ourtel?lat=38.5566&amp;ns=North&amp;lon=213.285&amp;fov=45&amp;z=1" />
<area shape="rect" coords="470,95,545,170" alt="40.2684,232.160"
href="/cgi-bin/
Yourtel?lat=40.2684&amp;ns=North&amp;lon=232.160&amp;fov=45&amp;z=1" />
<area shape="rect" coords="470,170,545,245" alt="35.3917,253.395"
href="/cgi-bin
/Yourtel?lat=35.3917&amp;ns=North&amp;lon=253.395&amp;fov=45&amp;z=1" />
<area shape="rect" coords="470,245,545,320" alt="23.0317,270.958"
href="/cgi-bin
/Yourtel?lat=23.0317&amp;ns=North&amp;lon=270.958&amp;fov=45&amp;z=1" />
<area shape="rect" coords="470,320,545,395" alt="5.7588,282.432"
href="/cgi-bin/
Yourtel?lat=5.7588&amp;ns=North&amp;lon=282.432&amp;fov=45&amp;z=1" />
<area shape="rect" coords="470,395,545,470" alt="-12.8447,288.823"
href="/cgi-bi
n/Yourtel?lat=12.8447&amp;ns=South&amp;lon=288.823&amp;fov=45&amp;z=1" />
<area shape="rect" coords="470,470,545,545" alt="-30.1303,291.429"
href="/cgi-bi
n/Yourtel?lat=30.1303&amp;ns=South&amp;lon=291.429&amp;fov=45&amp;z=1" />
<area shape="rect" coords="470,545,545,619" alt="-44.8154,290.856"
href="/cgi-bi
n/Yourtel?lat=44.8154&amp;ns=South&amp;lon=290.856&amp;fov=45&amp;z=1" />
<area shape="rect" coords="545,20,619,95" alt="26.4997,216.082"
href="/cgi-bin/Y
ourtel?lat=26.4997&amp;ns=North&amp;lon=216.082&amp;fov=45&amp;z=1" />
<area shape="rect" coords="545,95,619,170" alt="25.7463,229.749"
href="/cgi-bin/
Yourtel?lat=25.7463&amp;ns=North&amp;lon=229.749&amp;fov=45&amp;z=1" />
<area shape="rect" coords="545,170,619,245" alt="20.6382,244.148"
href="/cgi-bin
/Yourtel?lat=20.6382&amp;ns=North&amp;lon=244.148&amp;fov=45&amp;z=1" />
<area shape="rect" coords="545,245,619,320" alt="10.8382,256.796"
href="/cgi-bin
/Yourtel?lat=10.8382&amp;ns=North&amp;lon=256.796&amp;fov=45&amp;z=1" />
<area shape="rect" coords="545,320,619,395" alt="-2.3921,266.127"
href="/cgi-bin
/Yourtel?lat=2.3921&amp;ns=South&amp;lon=266.127&amp;fov=45&amp;z=1" />
<area shape="rect" coords="545,395,619,470" alt="-16.9564,271.889"
href="/cgi-bi
n/Yourtel?lat=16.9564&amp;ns=South&amp;lon=271.889&amp;fov=45&amp;z=1" />
<area shape="rect" coords="545,470,619,545" alt="-30.9728,274.380"
href="/cgi-bi
n/Yourtel?lat=30.9728&amp;ns=South&amp;lon=274.380&amp;fov=45&amp;z=1" />
<area shape="rect" coords="545,545,619,619" alt="-43.2794,273.825"
href="/cgi-bi
n/Yourtel?lat=43.2794&amp;ns=South&amp;lon=273.825&amp;fov=45&amp;z=1" />
</map>
<center><h1>Sky above 355'N 10639'3&quot;W at Fri 2009 Feb 6 21:00
UTC</h1></c
enter>
<center>
<a href="/yoursky/help/sky.html"><em><font size="-1">Explain symbols in the
map.
</font></em></a><br />
<img
src="/cgi-bin/Yoursky?di=993798CF5A500FD0F5203A94A187DA027397F0AB1B0A1AEAC0
15D57B1F667D586C4450676C349655D73C3607D5C3B1C2655E87486371C1D7DB4DC369B8420AE695
6B14B20E776E571CA9B59F28B7684ADF735EEB8A" usemap="#telmap" ismap="ismap"
width="
640" height="640" border="0" alt="Map of sky above 355'N 10639'3&quot;W
at Fri
2009 Feb 6 21:00 UTC" /><br />
<em>Click in map to aim telescope.</em>
<br /><a
href="/cgi-bin/Yourhorizon?lat=35.083600&amp;lon=106.651000&amp;azimuth
=0&amp;z=2&amp;elements="><b>View horizon at this observing site.</b></a>
</center>
<form method="post" name="request" action="/cgi-bin/Yoursky">
<center>

<input type="submit" value="Update" />

<p />

<a href="/yoursky/help/controls.html"><em>Explain controls in the following
pane
l.</em></a>
<table border="border" cellpadding="5">

<tr>
<th>
<a href="/yoursky/help/controls.html#DateTime"><b>Date and
Time</b></a>
</th>
<td>
<table>
<tr>
<td>
<input type="radio" name="date" onclick="0" checked="checked" value="0" />
<a hr
ef="/yoursky/help/controls.html#Now">Now</a>
</td>
</tr>
<tr>
<td>
<input type="radio" name="date" onclick="0" value="1" /> <a
href="/yoursky/help/
controls.html#UTC">Universal time:</a>
</td>
<td>
<input type="text" name="utc" value="2009-02-06 21:00:39" size="20"
onchange="do
cument.request.date[1].checked=true;" />
</td>
</tr>
<tr>
<td>
<input type="radio" name="date" onclick="0" value="2" /> <a
href="/yoursky/help/
controls.html#Julian">Julian day:</a>
</td>
<td>
<input type="text" name="jd" value="2454869.37545" size="20"
onchange="document.
request.date[2].checked=true;" />
</td>
</tr>
</table>

</td>
</tr>
<tr>
<th>
<a href="/yoursky/help/controls.html#Site">Observing Site</a>
</th>
<td>
<table cellpadding="3">
<tr>
<td>
Latitude:
</td>
<td>
<input type="text" name="lat" value="355'" size="10" />
</td>
<td>
<label><input type="radio" name="ns" checked="checked" value="North" />
North</l
abel>
<label><input type="radio" name="ns" value="South" /> South</label>
</td>
</tr>
<tr>
<td>
Longitude:
</td>
<td>
<input type="text" name="lon" value="10639'3&quot;" size="10" />
</td>
<td>
<label><input type="radio" name="ew" value="East" /> East</label>
<label><input type="radio" name="ew" checked="checked" value="West" />
West</lab
el>
</td>
</tr>

<tr>
<td align="center">
<a href="/yoursky/cities.html"><b>Set for nearby city</b></a>
</td>
</tr>

</table>

</td>
</tr>
<tr>
<th><a href="/yoursky/help/controls.html#Options">Display Options</a>
</th>
<td>
<input type="checkbox" checked="checked" name="coords" /> <a
href="/yoursky/help
/controls.html#Coords">Ecliptic and equator</a>

<br />
<input type="checkbox" checked="checked" name="moonp" /> <a
href="/yoursky/help/
controls.html#Planets">Moon and planets</a>

<br />
<input type="checkbox" checked="checked" name="deep" /> <a
href="/yoursky/help/
controls.html#DeepSky">Deep sky objects of magnitude</a>
<input type="text" name="deepm" value="2.5" size="3" /> and brighter

<br />
<a href="/yoursky/help/controls.html#Constellations">Constellations:</a>
<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<input type="checkbox"
checked="
checked" name="consto" /> <a
href="/yoursky/help/controls.html#ConstO">Outlines<
/a>
<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<input type="checkbox"
checked="
checked" name="constn" /> <a
href="/yoursky/help/controls.html#ConstN">Names</a>

<label><input type="checkbox" name="consta" /> aligned with
horizon?</label>
<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<input type="checkbox"
checked="
checked" name="constb" /> <a
href="/yoursky/help/controls.html#ConstB">Boundarie
s</a>

<br />
<a href="/yoursky/help/controls.html#Stars">Stars:</a>
<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a
href="/yoursky/help/controls.
html#StarMag">Show stars brighter than magnitude</a>
<input type="text" name="limag" value="5.5" size="3" />
<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<input type="checkbox"
checked="
checked" name="starn" /> <a
href="/yoursky/help/controls.html#StarName">Names fo
r magnitude</a>
<input type="text" name="starnm" value="2.0" size="3" /> and brighter
<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<input type="checkbox"
checked="
checked" name="starb" /> <a
href="/yoursky/help/controls.html#StarBFlam">Bayer/F
lamsteed codes</a> for mag.
<input type="text" name="starbm" value="2.5" size="3" /> and brighter

<br /><input type="checkbox" name="flip" /> <a
href="/yoursky/help/controls.html
#Invert">Invert North and South</a>

<br /><a href="/yoursky/help/controls.html#Imgsize">Image size</a>: <input
type=
"text" name="imgsize" value="640" size="6" /> pixels

<br /><a href="/yoursky/help/controls.html#Scheme">Colour scheme</a>:
<select na
me="scheme" size="1">
<option value="0" selected="selected">Colour</option>
<option value="1">Black on white background</option>
<option value="2">White on black background</option>
<option value="3">Night vision (red)</option>
</select>

</td>
</tr>
<tr>
</th>
<td align="center">
<br />
Paste <a href="/yoursky/help/elements.html">orbital elements</a> below:
<br />
<textarea name="elements" rows="1" cols="40">
</textarea><br />
</td>
</tr>
</table>

</center>
</form>

<p />
<a href="/yoursky/help/ephemeris.html"><b>Ephemeris:</b></a><center>
<table border="border" cellpadding="3">
<tr><th rowspan="2">&nbsp;</th><th rowspan="2">Right<br />Ascension</th><th
rows
pan="2">Declination</th><th rowspan="2">Distance<br />(<span
title="Astronomical
units (149,597,871 km)">AU</span>)</th><th colspan="2">From 355'N
10639'3&quo
t;W:</th></tr>
<tr><th>Altitude</th><th>Azimuth</th></tr>
<tr><th><a href="/cgi-bin/uncgi/Yourtel?aim=0&amp;z=1">Sun</a></th><td
align="ri
ght">21h 22m 35s</td><td align="right">&minus;15 22.3'</td><td
align="right">0.
986</td><td align="right">34.252</td><td
align="right">29.521</td><td>Up</td></t
r>
<tr><th><a href="/cgi-bin/uncgi/Yourtel?aim=1&amp;z=1">Mercury</a></th><td
align
="right">19h 40m 10s</td><td align="right">&minus;19 45.0'</td><td
align="right
>0.863 said:
<tr><th><a href="/cgi-bin/uncgi/Yourtel?aim=2&amp;z=1">Venus</a></th><td
align="
right">0h 7m 4s</td><td align="right">+3 25.6'</td><td
align="right">0.516</td>
<tr><th><a href="/cgi-bin/uncgi/Yourtel?aim=3&amp;z=1">Moon</a></th><td
align="r
ight">6h 46m 2s</td><td align="right">+25 35.2'</td><td align="right">57.0
<spa
n title="Earth radii (6378.14 km)">ER</span></td><td
align="right">&minus;4.237<
/td><td align="right">&minus;125.539</td><td>Set</td></tr>
<tr><th><a href="/cgi-bin/uncgi/Yourtel?aim=4&amp;z=1">Mars</a></th><td
align="r
ight">20h 16m 46s</td><td align="right">&minus;20 44.0'</td><td
align="right">2
..336</td><td align="right">21.729</td><td
align="right">41.785</td><td>Up</td></
tr>
<tr><th><a href="/cgi-bin/uncgi/Yourtel?aim=5&amp;z=1">Jupiter</a></th><td
align
="right">20h 40m 29s</td><td align="right">&minus;18 49.2'</td><td
align="right
>6.067 said:
<tr><th><a href="/cgi-bin/uncgi/Yourtel?aim=6&amp;z=1">Saturn</a></th><td
align=
"right">11h 28m 50s</td><td align="right">+5 45.5'</td><td
align="right">8.530<
/td><td align="right">&minus;48.690</td><td
align="right">170.062</td><td>Set</t
d></tr>
<tr><th><a href="/cgi-bin/uncgi/Yourtel?aim=7&amp;z=1">Uranus</a></th><td
align=
"right">23h 27m 5s</td><td align="right">&minus;4 21.0'</td><td
align="right">2
0.923</td><td align="right">50.147</td><td
align="right">&minus;9.577</td><td>Up
</td></tr>
<tr><th><a href="/cgi-bin/uncgi/Yourtel?aim=8&amp;z=1">Neptune</a></th><td
align
="right">21h 44m 39s</td><td align="right">&minus;13 57.0'</td><td
align="right
">31.015</td><td align="right">37.604</td><td
align="right">24.097</td><td>Up</t
d></tr>
<tr><th><a href="/cgi-bin/uncgi/Yourtel?aim=9&amp;z=1">Pluto</a></th><td
align="
right">18h 9m 47s</td><td align="right">&minus;17 44.2'</td><td
align="right">3
2.271</td><td align="right">2.886</td><td
align="right">65.911</td><td>Up</td></
tr>
</table>
</center>
<blockquote>
<small>Azimuth in the above table
follows the astronomical convention: zero
degrees is South with positive angles toward the
West and negative angles toward the East.</small>
</blockquote><p />
<a href="/yoursky/#Skymap"><b>Back to <em>Sky Maps</em></b></a>
&nbsp;&nbsp;<a href="/yoursky/"><b>Up to <em>Your Sky</em></b></a>
&nbsp;&nbsp;<a href="/yoursky/credits.html"><b>Credits</b></a>
&nbsp;&nbsp;<a href="/yoursky/custom.html"><b>Customise</b></a>
&nbsp;&nbsp;<a href="/yoursky/help/help.html"><b>Help</b></a>
<p />
<hr />
<address>
by <a href="/">John Walker</a>
</address>
<p />
<blockquote>
<font size="-1"><em>Images produced by Your Sky are in the public
domain and may be used in any manner without permission, restriction,
attribution, or compensation. Back links to
<a href="http://www.fourmilab.ch/yoursky/">Your Sky</a> are
welcome.</em></font>

</blockquote>
</body>
</html>


C:\MinGW\source>
 
L

Larry Gates

Yes, that is absolutely a problem. So fix it.

I've asked this question before and didn't get an answer I could use. How
does a person do proper line continuations in perl?
--
larry gates

So please don't think I have a "down" on the MVS people. I'm just pulling
off their arms to beat other people over the head with.
-- Larry Wall in <[email protected]>
 
T

Tim Greer

Larry said:
Big pimpin, Tim.

use strict;
use warnings;
use LWP::Simple;

# load the complete content of the url in question
# via LWP::Simple::get(...)

my $site_url = 'http://www.fourmilab.ch/cgi-bin/Yoursky';
my $url_args = 'z=1&lat=35.0836&ns=North&lon=106.651&ew=West';

my $t = 'Something went right!';
print "t is $t\n";

$t = (get "$site_url?$url_args" or "Problem");


print "t is $t\n";


# perl scraper3.pl

#end script show target

<td>
<input type="text" name="jd" value="2454869.37545" size="20"

How do I grab the julian date from this? Full page listing after sig.

Well, first of all that was just in response to someone mentioning or,
I'd change the code:

my $site_url = 'http://www.fourmilab.ch/cgi-bin/Yoursky';
my $url_args = 'z=1&lat=35.0836&ns=North&lon=106.651&ew=West';
my $t = get "$site_url?$url_args" || "There was a problem".

I'd also consider using something else, like useragent, so you know what
the problem was, instead of just having it be undefined. Sometimes you
can act on the problem, or at least know not to try again if it's
forbidden on the target site, or whatever else.

You can grab the Julian date with something like:

my $juldate = ($t =~ m/name="jd" value="([^"]+)"/) ? $1 : "No date";

Of course, there are dozens of ways of doing this.
 
T

Tim Greer

Larry said:
I've asked this question before and didn't get an answer I could use.
How does a person do proper line continuations in perl?

Probably, something like:

my $t = get(
'http://www.fourmilab.ch/cgi-bin/Yoursky?' .
'z=1&lat=35.0836&ns=North&lon=106.651&ew=West'
) || "There was a problem.";
print "t is $t\n";

Would work.

The other methods are as I mentioned before. Set a variable for the
domain, URL and args and just pass it to get() that way.
 
L

Larry Gates

By pressing the wide key labeled "Enter" or "Return" on your keyboard. :)


If you instead meant to ask how to get a really long string that
does not hit the wordwrap limit, then use the concatenation operator:

my $t = get 'http://www.fourmilab.ch/cgi-'
. 'bin/'
. 'Yoursky?z=1&lat=35.0836&ns=North&lon=106.651&ew=West';

That explains the error expecting a period.

Hoe does a perl program say read lines until one of them contains 'jd', and
indeed if it contains this tring, then it's the only one wecare about for
now.

My hands are injured.
--
larry gates

Real theology is always rather shocking to people who already
think they know what they think. I'm still shocked myself. :)
-- Larry Wall in <[email protected]>
 
T

Tad J McClellan

Hoe does a perl program say read lines until one of them contains 'jd',


Are you serious, or are you joking around?

while ( <> ) {
last if /jd/;
}
print "There is a jd in this line: $_";
 
L

Larry Gates

Are you serious, or are you joking around?

while ( <> ) {
last if /jd/;
}
print "There is a jd in this line: $_";

No, I'm not kidding. It's new syntax for me.

Dietrich Bonhoefeer spoke of the last, and the penultimate, dat Vorletzte.

If you canbump execution back oneline, can you capture what lies onthe same
line with 'jd'.
--
larry gates

And you can still put in all that cruft if you want to. You can even
force yourself to have to do it. But to me, it feels a bit like slavery,
so I'm still looking for a land flowing with milk and honey, even if
there are a few giants in it. -- Larry Wall
 

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments. After that, you can post your question and our members will help you out.

Ask a Question

Members online

No members online now.

Forum statistics

Threads
473,744
Messages
2,569,484
Members
44,903
Latest member
orderPeak8CBDGummies

Latest Threads

Top