Re: Can't use string as a symbol ref

[Chas. Owens]

On Dec 17, 2007 10:19 AM, ciwei2103 <[EMAIL PROTECTED]> wrote:
> Can somebody enlighten me what I'm doing wrong?
>
> I have a list in a file , "test.dat"
>
> sh> cat test1.dat
> 0039
> 0038
>
> sh>  cat test1.pl
> #!/usr/bin/perl -w
> use strict;
> my $input = $ARGV[0];
>
> my @devices =  <$input>  ;
> print "devices =  @devices \n";
>
> __END__
>
> now run it with
> sh> test.pl test1.dat
>
> Can't use string ("test1.dat") as a symbol ref while "strict refs" in
> use at ./test.pl line xx.

In addition to using open as others have suggested, if the only
arguments the script is expecting are files to process, you don't need
to use open; the <> operator will automagically open files named in
@ARGV if given no file handle:

#!/usr/bin/perl

use strict;
use warnings;

my @devices = <>;
print "devices = @devices\n";

However, it is considered a bad idea to slurp all of a file into an
array (unless you are one hundred percent certain the files are
small).  It is better to write your code to handle things in pieces (a
line at a time).  A common way to do this is to use a while loop:

#!/usr/bin/perl

use strict;
use warnings;

while (my $device = <>) {
#do something with each device
}

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Re: Can't use string as a symbol ref

[yitzle]

Maybe tell us what you are trying to do?
Try this:

> #!/usr/bin/perl -w
> use strict;
> my $input = $ARGV[0];

# File handle
my $FH;

# Check the file is a normal file and exists
die "File does not exist\n" if not -f $input;

# Open the file handle for read only, file named by $input
# Or die and print $! which is probably not the error message
# variable. perlvar would tell you the corrent variable.
open $FH, '<', $input or die "$!";

# Read from the file handle
my @devices =  <$FH>  ;

# The the array elements with a ", "
> print "devices =  ", join (", ", @devices), " \n";
>
> __END__

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Re: Can't use string as a symbol ref

[Tom Phoenix]

On 12/17/07, ciwei2103 <[EMAIL PROTECTED]> wrote:

> Can somebody enlighten me what I'm doing wrong?

> my $input = $ARGV[0];
>
> my @devices =  <$input>  ;

$input is a string, since it comes from @ARGV; but you're using it as
if it's a filehandle. Do you need open()? Hope this helps!

--Tom Phoenix
Stonehenge Perl Training

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Can't use string as a symbol ref

[ciwei2103]

Can somebody enlighten me what I'm doing wrong?

I have a list in a file , "test.dat"

sh> cat test1.dat
0039
0038

sh>  cat test1.pl
#!/usr/bin/perl -w
use strict;
my $input = $ARGV[0];

my @devices =  <$input>  ;
print "devices =  @devices \n";

__END__

now run it with
sh> test.pl test1.dat

Can't use string ("test1.dat") as a symbol ref while "strict refs" in
use at ./test.pl line xx.


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