Re: Error binmode() on unopened filehandle

Once you go to BINMODE on a file handle, a record separator makes no sense.
A more typical way to read a large binary file would be statements like this:

binmode INBIN;
my $n_bytes = read(INBIN, $buff, $BUFSIZE);
[download]

That's a request to read $BUFSIZE bytes from INBIN into $buff. $n_bytes is number of bytes actually read from INBIN.
I've never wound up reading a binary file in a single shot into a Perl variable because my bin files are not appropriate for that (so big they need to be read in chunks). However, I guess this would work (untested):

use MIME::Base64;
use strict;
use warnings;

my $upload_dir = 'uploaded_files';
my $file_name = 'image.jpg';

### Open the image to convert to base64
open (IMAGE, '<', "$upload_dir/$file_name") or die "$!";
binmode IMAGE;
my $binary = <IMAGE>;

my $base64 = encode_base64(pack('B*', $binary));
    
print "base64 = $base64\n";
[download]

Comment on Re: Error binmode() on unopened filehandle Select or Download Code

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Re^2: Error binmode() on unopened filehandle by jo37 (Deacon) on May 03, 2020 at 14:03 UTC
Once you go to BINMODE on a file handle, a record separator makes no sense. Maybe you should have tested this. `#!/usr/bin/perl use strict; use warnings; binmode DATA; my $binary = <DATA>; print "$binary\n"; __DATA__ first second` [download] This gives: `first` [download] Greetings, -jo `$gryYup$d0ylprbpriprrYpkJl2xyl~rzg??P~5lp2hyl0p$`	[reply] [d/l] [select]
Re^3: Error binmode() on unopened filehandle by Marshall (Canon) on May 03, 2020 at 14:26 UTC
Ok, I tested with a .jpg file I had laying around. `use warnings; use strict; open (my $fh, '<', "COVID19-Death02Apr.jpg") or die "$!"; binmode $fh; my $binary = <$fh>; #entire binary file goes to Perl variable print '',$binary;` [download] Works just fine! What you are overlooking is that you must set binmode before reading from the file. The Perl DATA file handle is an open file handle to the Perl program source that is seeked to the first character on the next line after __DATA__. This is buffered character mode I/O. You can't switch modes in the midst of a file.	[reply] [d/l]
Re^4: Error binmode() on unopened filehandle by haukex (Archbishop) on May 03, 2020 at 15:55 UTC
You can't switch modes in the midst of a file. You sure can: use warnings; use strict; use utf8; use Data::Dumper; $Data::Dumper::Useqq=1; print join(", ",PerlIO::get_layers(DATA)),"\n"; print Dumper( scalar <DATA> ); binmode DATA; print join(", ",PerlIO::get_layers(DATA)),"\n"; print Dumper( scalar <DATA> ); __DATA__ H∃llⓄ, 🗺! H∃llⓄ, 🗺! Output: `unix, perlio, utf8 $VAR1 = "H\x{2203}ll\x{24c4}, \x{1f5fa}!\n"; unix, perlio $VAR1 = "H\342\210\203ll\342\223\204, \360\237\227\272!\n";` [download]	[reply] [d/l]
Re^5: Error binmode() on unopened filehandle by Marshall (Canon) on May 03, 2020 at 21:54 UTC
Re^4: Error binmode() on unopened filehandle by jo37 (Deacon) on May 03, 2020 at 14:32 UTC
I disagree. What about this: `#!/usr/bin/perl use strict; use warnings; my $data = <<EOF; first second EOF open my $fh, '<', \$data; binmode $fh; my $binary = <$fh>; print "$binary\n";` [download] Greetings, -jo `$gryYup$d0ylprbpriprrYpkJl2xyl~rzg??P~5lp2hyl0p$`	[reply] [d/l]
Re^5: Error binmode() on unopened filehandle by Marshall (Canon) on May 03, 2020 at 15:41 UTC
Re^6: Error binmode() on unopened filehandle by haukex (Archbishop) on May 03, 2020 at 16:05 UTC
Some notes below your chosen depth have not been shown here
Re^6: Error binmode() on unopened filehandle by jo37 (Deacon) on May 03, 2020 at 15:52 UTC
Re^6: Error binmode() on unopened filehandle by ikegami (Patriarch) on May 04, 2020 at 03:33 UTC
Some notes below your chosen depth have not been shown here
Re^5: Error binmode() on unopened filehandle by Marshall (Canon) on May 03, 2020 at 14:39 UTC
Re^6: Error binmode() on unopened filehandle by jo37 (Deacon) on May 03, 2020 at 14:54 UTC
Re^6: Error binmode() on unopened filehandle by ikegami (Patriarch) on May 04, 2020 at 03:27 UTC
Re^4: Error binmode() on unopened filehandle by ikegami (Patriarch) on May 04, 2020 at 03:29 UTC
Works just fine! That will only read until the first 0A byte. You need `local $/;`	[reply] [d/l]


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