Why Premature end of script headers?
Hi all,
I've made a little script that takes the lines from a file, removes the
dupplicate lines and prints the result to a new file.
I've read the original file line by line because it is a big file (over 7
MB).
The problem is that after printing almost 10% from the original file into
the new file, the script dies and the only error I get in the log file is:
[Mon Jul 15 14:44:48 2002] [error] [client 127.0.0.1] Premature end of
script headers: clean.pl
I've checked the original file to see if there are some strange characters
in that line, or in the next one, but I haven't found something that might
cause that problem.
Please tell me why is the script dying only after it runs for a few minutes,
and after writing over 11000 lines, and not from the beginning, if there is
a problem with the script.
Can you find any problems with my scriptt?
Thank you very very much!
Here is the script:
#!/perl/bin/perl -w
print Content-type: text/html\n\n;
#The original file:
my $file = f:/teddy/data/er.txt;
#The result:
my $out = f:/teddy/data/er_new_good.txt;
#Create the result file (empty):
open (OUT, $out);
print OUT ;
close OUT;
#Open the original file:
open (FILE, $file);
line: while (FILE) {
my $line = $_;
#Open the result file:
open (OUT, $out);
while (OUT) {
#Checks if the line from the original file exists in the result file:
if ($line eq $_) {
#If the line exists, jump back and read the next line from the original
file:
next line;
}
else {
#Read the next line from the result file:
next;
}
#End while for the result file:
}
close OUT;
#Open the result file and append the line that was not found:
open (OUT, $out);
print OUT $line;
close OUT;
#Close the while loop for the original file:
}
Teddy Center: http://teddy.fcc.ro/
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RE: Why Premature end of script headers?
-Original Message- From: Octavian Rasnita [mailto:[EMAIL PROTECTED]] Sent: Monday, July 15, 2002 8:18 AM To: [EMAIL PROTECTED] Subject: Why Premature end of script headers? Hi all, I've made a little script that takes the lines from a file, removes the dupplicate lines and prints the result to a new file. I've read the original file line by line because it is a big file (over 7 MB). The problem is that after printing almost 10% from the original file into the new file, the script dies and the only error I get in the log file is: [Mon Jul 15 14:44:48 2002] [error] [client 127.0.0.1] Premature end of script headers: clean.pl I've checked the original file to see if there are some strange characters in that line, or in the next one, but I haven't found something that might cause that problem. Please tell me why is the script dying only after it runs for a few minutes, and after writing over 11000 lines, and not from the beginning, if there is a problem with the script. Can you find any problems with my scriptt? Probably your web server is timing out the request and killing your script. Web servers don't like to run long-running processes like this. Perhaps you can fork off a child and have the child take care of it. See http://www.stonehenge.com/merlyn/WebTechniques/col20.html for a nice technique on this. -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Why Premature end of script headers?
Hi, On Mon, 15 Jul 2002, Octavian Rasnita wrote: I've made a little script that takes the lines from a file, removes the dupplicate lines and prints the result to a new file. The problem is that after printing almost 10% from the original file into the new file, the script dies and the only error I get in the log file is: [Mon Jul 15 14:44:48 2002] [error] [client 127.0.0.1] Premature end of script headers: clean.pl #!/perl/bin/perl -w print Content-type: text/html\n\n; I'm not sure why you are doing this. You never output anything to the web page aside from the header. Did you want this to be a web application? If so, you know the web server needs the correct permissions to manipulate the files. You would catch permission problems if you check the error return $! from your open statements. That's always a wise thing to do. As for editing files, take a look at Tie::File. -lisa -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Why Premature end of script headers?
Probably your web server is timing out the request and killing your
script. Web servers don't like to run long-running processes like
this. Perhaps you can fork off a child and have the child take care
of it.
Another solution is to have something like the following in your loop:
--
local $|=1; # print things right away (no buffering)
# $ltime and $ctime should be defined before the loop
$ctime = time();
if ($ltime ne $ctime){
print . ;
$ltime = $ctime;
}
--
Then the browser does not time out because it continually gets information, so it
simply prints
another period to the browser every one second that it is working. This can help you
know its still
working.
Regards,
David
- Original Message -
From: Bob Showalter [EMAIL PROTECTED]
To: 'Octavian Rasnita' [EMAIL PROTECTED]; [EMAIL PROTECTED]
Sent: Monday, July 15, 2002 9:28 AM
Subject: RE: Why Premature end of script headers?
-Original Message-
From: Octavian Rasnita [mailto:[EMAIL PROTECTED]]
Sent: Monday, July 15, 2002 8:18 AM
To: [EMAIL PROTECTED]
Subject: Why Premature end of script headers?
Hi all,
I've made a little script that takes the lines from a file,
removes the
dupplicate lines and prints the result to a new file.
I've read the original file line by line because it is a big
file (over 7
MB).
The problem is that after printing almost 10% from the
original file into
the new file, the script dies and the only error I get in the
log file is:
[Mon Jul 15 14:44:48 2002] [error] [client 127.0.0.1] Premature end of
script headers: clean.pl
I've checked the original file to see if there are some
strange characters
in that line, or in the next one, but I haven't found
something that might
cause that problem.
Please tell me why is the script dying only after it runs for
a few minutes,
and after writing over 11000 lines, and not from the
beginning, if there is
a problem with the script.
Can you find any problems with my scriptt?
Probably your web server is timing out the request and killing your
script. Web servers don't like to run long-running processes like
this. Perhaps you can fork off a child and have the child take care
of it.
See http://www.stonehenge.com/merlyn/WebTechniques/col20.html for a
nice technique on this.
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RE: Why Premature end of script headers?
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
Sent: Monday, July 15, 2002 12:23 PM
To: 'Octavian Rasnita'; [EMAIL PROTECTED]
Subject: Re: Why Premature end of script headers?
Probably your web server is timing out the request and killing your
script. Web servers don't like to run long-running processes like
this. Perhaps you can fork off a child and have the child take care
of it.
Another solution is to have something like the following in your loop:
--
local $|=1; # print things right away (no buffering)
# $ltime and $ctime should be defined before the loop
$ctime = time();
if ($ltime ne $ctime){
print . ;
$ltime = $ctime;
}
--
Then the browser does not time out because it continually
gets information, so it simply prints
another period to the browser every one second that it is
working. This can help you know its still
working.
True. But there are two possible downsides to consider:
1. It ties up a server process for an extended period.
2. The server will kill the CGI script if the client goes away
or the connection is lost.
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Re: Why Premature end of script headers?
Yes, your right.
It seems to me there has got to be a more efficient way to accomplish what is
being attempted.
Right now, the solution is making a copy of the file, then checking every line of the
original
against every line of the copy. This method becomes exponentially more processor
intensive for
additional lines to the file. Perhaps a recognize would be to loop through the lines,
give them a
line number, and write them to a copy. Then sort the copy alphanumerically, then loop
through the
copy checking one line against the next, and if the next is a duplicate, through it
away, and
continue checking it against the next until they are not the same. As soon as their
not the same,
take the line that is not the same and begin checking it against the next line. So on
and so forth.
Because every like line will be right next to each other, you don't have to check each
line against
every other line, just the ones next to it. After your done eliminating the
duplicates, sort the
file again by line number (this only if its necessary to keep them in a certain
order), and your
done. Granted this method requires that you find some efficient manner of sorting the
lines in
large text files, but if somebody knows of something that can do this, viola.
Regards,
David
- Original Message -
From: Bob Showalter [EMAIL PROTECTED]
To: [EMAIL PROTECTED]; [EMAIL PROTECTED]
Sent: Monday, July 15, 2002 12:00 PM
Subject: RE: Why Premature end of script headers?
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
Sent: Monday, July 15, 2002 12:23 PM
To: 'Octavian Rasnita'; [EMAIL PROTECTED]
Subject: Re: Why Premature end of script headers?
Probably your web server is timing out the request and killing your
script. Web servers don't like to run long-running processes like
this. Perhaps you can fork off a child and have the child take care
of it.
Another solution is to have something like the following in your loop:
--
local $|=1; # print things right away (no buffering)
# $ltime and $ctime should be defined before the loop
$ctime = time();
if ($ltime ne $ctime){
print . ;
$ltime = $ctime;
}
--
Then the browser does not time out because it continually
gets information, so it simply prints
another period to the browser every one second that it is
working. This can help you know its still
working.
True. But there are two possible downsides to consider:
1. It ties up a server process for an extended period.
2. The server will kill the CGI script if the client goes away
or the connection is lost.
--
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
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To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
