CODEWITHSUNDEEP
perlfile-io
Mike Thornley
Mike Thornley

Reputation: 421

filehandle - won't write to a file

I cannot get the script below to write to the file, data.txt, using a FILEHANDLE. Both the files are in the same folder, so that's not the issue. Since I started with Perl, I have noticed to run scripts, I have to use a full path: c:\programs\scriptname.pl and also the same method to input files. I thought that could be the issue and tried this syntax below but that didn't work either...

open(WRITE, ">c:\programs\data.txt") || die "Unable to open file data.txt: $!";

Here is my script. I have checked the syntax until it makes me crazy and cannot see an issue. Any help would be greatly appreciated!. I'm also puzzled, why the die function hasn't kicked in.

#!c:\strawberry\perl\bin\perl.exe

#strict
#diagnostics
#warnings

#obtain info in variables to be written to data.txt
print("What is your name?");
$name = <STDIN>;
print("How old are you?");
$age = <STDIN>;
print("What is your email address?");
$email = <STDIN>;

#data.txt is in the same file as this file.
open(WRITE, ">data.txt") || die "Unable to open file data.txt: $!";

#print information to data.txt
print WRITE "Hi, $name, you are \s $age and your email is \s $email";

#close the connection
close(WRITE);

How I solved this problem solved.

I have Strawberry Perl perl.exe installed on the c: drive, installed through and using the installer with a folder also on c with my scripts in, which meant I couldn't red/write to a file (directional or using functions, ie the open one) and I always had to use full paths to launch a script. I solved this problem after a suggestion of leaving the interpreter installed where it was and moving my scripts file to the desktop (leave the OS command in the first line of the script where it is as the interpreter is still in the same place it was initially). Now I can run the scripts with one click and read/write and append to file with CMD prompt and using Perl functions with ease.

Upvotes: 0

Views: 2694

Answers (4)

Dave Cross
Dave Cross

Reputation: 69224

Backslashes have a special meaning in double-quoted strings. Try escaping the backslashes.

open(WRITE, ">c:\\programs\\data.txt") || die ...;

Or, as you're not interpolating variables, switch to single quotes.

open(WRITE, '>c:\programs\data.txt') || die ...;

It's also worth using the three-argument version of open and lexical filehandles.

open(my $write_fh, '>', 'c:\programs\data.txt') || die ...;

Upvotes: 2

reuteras
reuteras

Reputation: 11

If you have an access problem when you try to print to data.txt you can change that line to:

print WRITE "Hi, $name, you are \s $age and your email is \s $email" || die $!;

to get more information. A read only file will cause this error message:

Unable to open file data.txt: Permission denied at perl.pl line 12, <STDIN> line 3.

Upvotes: 1

Brad Gilbert
Brad Gilbert

Reputation: 34120

You may want to try FindBin.

use strict;
use warnings;
use autodie; # open will now die on failure

use FindBin;
use File::Spec::Functions 'catfile';
my $filename = catfile $FindBin::Bin, 'data.txt';

#obtain info in variables to be written to data.txt
print("What is your name?"); my $name = <STDIN>;
print("How old are you?"); my $age = <STDIN>;
print("What is your email address?"); my $email = <STDIN>;

{
  open( my $fh, '>', $filename );
  print {$fh} "Hi, $name, you are $age, and your email is $email\n";
  close $fh;
}

Upvotes: 1

Miguel Prz
Miguel Prz

Reputation: 13792

you must use "/" to ensure portability, so: open(WRITE, ">c:/programs/data.txt") Note: I assume that c:/programs folder exists

Upvotes: 1

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