On 17/03/2011 15:56, Chris Stinemetz wrote:
I'm trying to use file path for my file that I want to read but I am
getting the following error when trying to use strict.
Can't use string ("C://temp//PCMD") as a symbol ref while "strict
refs" in use at ./DOband.pl line 10.
Any help is greatly appreciated.
#!/usr/bin/perl
use warnings;
use strict;
my $filepath = "C://temp//PCMD";
You are getting confused with backward and forward slashes. Backward
slashes are the proper delimiter for Windows file paths, and require
escaping in strings with a second back slash. However Perl is kind and
allows either forward or backward slashes to serve the same purpose, but
a plain forward slash doesn't require escaping.
What you have written contains pairs of forward slashes which, luckily,
is interpreted the same as a single slash, so ultimately your code does
what it is supposed to.
You should either take advantage of Perl's leniency and write
my $filepath = "C:/temp/PCMD";
or use single quotes (within which backslashes need escaping only if
they appear as the final character) and write
my $filepath = 'C:\temp\PCMD';
my $outfile = "output.txt";
open ("$filepath") || die "ERROR: opening $filepath\n";
Except for old-fashioned and exotic syntax, a call to open requires
three parameters:
- The variable to assign the open file handle to
- The open mode (usually read or write)
- The file path and name
Apart from this, it is very wrong to enclose a simple scalar variable in
quotes. Doing so does have a purpose, but it is an esoteric one and is
almost never what you want to do.
It is best to stick to the low-priority 'or' instead of '||' as the
latter will do what you want only if you have put parentheses around the
parameters to the open call.
You should always put the system variable $! into your die string, as it
explains the reason for the failure. It is also a bad idea to terminate
the die string with a newline, as it prevents die from displaying the
source file and line number where the failure occurred.
Putting these together, your code should read
open my $fh, '<', $filepath or die "ERROR opening $filepath: $!";
open (OUTFILE, "> $outfile") || die "ERROR: opening $outfile\n";
Interesting that you have remembered to include a file handle and an
open mode here! But the other points apply:
open my $outfile, '>', $outfile or die "ERROR opening $outfile: $!";
I hope this helps you.
Rob
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