Trying to Create and Write to a file

IPstacks has asked for the wisdom of the Perl Monks concerning the following question:

Well, it's question time again... I have the following code:

#!/usr/bin/perl -w
use strict;

# Modules to use
use Config::IniFiles;

# Variables
my ($CorE, $PlugInDir, $LogFile, $ForkLimit, $TftpRoot, $TftpPath, $Fi
+leStyle,
$DateStyle, $PreCmd, $PostCmd, $SNMPver, $SNMPretry, $SNMPwait, $SNMPm
+tu,
$SNMPdebug, $SNMPCommunity, $TFTPserver);

# Start

print 'Would you like to edit the current pancho configuration file
  or Create a new file [e/C]? ';$CorE=<STDIN>;

# Create new file
  if ($CorE eq 'C') {
  open (CREATE,">>pancho.conf");
    print CREATE "[Global]";
  print 'What is the IP address of your TFTP server? ';
  $TFTPserver=<STDIN>;
  print CREATE $TFTPserver;
  close (CREATE);
}
[download]

What I am trying to do is create a file when the user enters "C" as their answer. Then when it creates the file it will start the file heading with "Global" and all the user to then enter the ip address of their TFTP server. The script should then write their tftp server ip address to the file, close the file and then exit. However, what I have doesn't make anything in the if loop run. I enter "C" as my choice and then it just dies. I would appreciate any help you can offer.

Comment on Trying to Create and Write to a file Download Code

Replies are listed 'Best First'.
Re: Trying to Create and Write to a file by c (Hermit) on Apr 07, 2003 at 16:45 UTC
I'm guessing that you'll need to chomp the value of $CorE after you've read it in from STDIN. You're trying to match on just the value 'C', when perl is probably seeing 'C\n' as its value. -c	[reply]
Re: Re: Trying to Create and Write to a file by IPstacks (Novice) on Apr 07, 2003 at 16:48 UTC
That did the trick, thanks c	[reply]
Re: Re: Re: Trying to Create and Write to a file by Nkuvu (Priest) on Apr 07, 2003 at 19:21 UTC
Just as a suggestion, you may also want to consider ignoring the case of the input. For example if someone enters 'c' then it doesn't pass the conditional. You could use a simple regex such as `if ($CorE =~ /^C/i)` which would also eliminate the need for `chomp`ing.	[reply] [d/l] [select]
Re: Trying to Create and Write to a file by Improv (Pilgrim) on Apr 07, 2003 at 16:51 UTC
Change your open() call from `open (CREATE,">>pancho.conf");` [download] to `open(CREATE, ">pancho.conf") \|\| die "Could not open pancho.conf: $!\n" +;` [download] Notice that I changed the >> to just a > -- what you've said suggests that appending is less appropriate than truncating and then writing.	[reply] [d/l] [select]
Re: Trying to Create and Write to a file by Coplan (Pilgrim) on Apr 07, 2003 at 17:16 UTC
Just a quick comment. Whenever I'm using "if" loops, I always make sure to place an "else" as it helps with tracing. Especially in a situation like this, you would at least know that there wasn't a match: `if ($omething) { # do stuff } else { print "There was no match!\n"; # or some other error }` [download] You could easily place in a more intuative error message. Even if this is only temporary to help you test the code, it's a worthwhile practice to get into. --Coplan	[reply] [d/l]
Re: Trying to Create and Write to a file by Juerd (Abbot) on Apr 07, 2003 at 16:48 UTC
open (CREATE,">>pancho.conf"); print CREATE "[Global]"; close (CREATE); Could be anything. You're not checking the return values of these file related functions. Remember: open or die print or die close or die This goes for many other functions as well. `open CREATE, '>>pancho.conf' or die $!; print CREATE '[Global]' or die $!; close CREATE or die $!;` [download] You probably should be more verbose than just $!, but don't forget to include $!, since it contains the actual error message. That said, you should learn Perl. Try reading a book. Juerd - http://juerd.nl/ - spamcollector_perlmonks@juerd.nl (do not use).	[reply] [d/l]
Re: Re: Trying to Create and Write to a file by Nkuvu (Priest) on Apr 07, 2003 at 19:07 UTC
I have to offer apologies -- I originally was going to vote this note up based on the checking of errors. Then reconsidered based on the last line, and missed the null vote. So my vote should have been null, and I actually voted --.	[reply]
Re: Re: Re: Trying to Create and Write to a file by Juerd (Abbot) on Apr 07, 2003 at 19:18 UTC
So my vote should have been null, and I actually voted --. No need to apologize. Votes are anonymous, and I couldn't care much less ;) One wrong vote won't hurt anyone. Juerd - http://juerd.nl/ - spamcollector_perlmonks@juerd.nl (do not use).	[reply]


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