Re^2: Best way to read a file into memory and use normal operation on memory file?

Is there any reason this has to be done as a file in memory, instead of a simple scalar? Just replace your

syswrite $mem_file, pack( "v*", unpack("n*", $data ));

with

$mem_file .= pack( "v*", unpack("n*", $data ));

And of course, simply use my $mem_file; instead of the open my $mem_file...;

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Re^3: Best way to read a file into memory and use normal operation on memory file? by james28909 (Deacon) on Jul 16, 2014 at 23:17 UTC
yeah that def worked because i can byte reverse the file, then after the while loop i can write it to disk/hdd. i can also seek and read it ;) which is what i was after lol. here is the final working code: `open ( my $in_file, '<', "file" ); binmode( $in_file ); my $mem_file; binmode( $mem_file ); my ( $buf, $data, $n, $bytes ); while (( $n = read $in_file, $data, 4096 ) != 0){ $mem_file .= pack( "v", unpack("n", $data )); $bytes+=$n; } open ( my $otherMem_file, '<', \$mem_file ); binmode( $otherMem_file ); seek $otherMem_file, 0x00, 0; read $otherMem_file, my $temp, 0x1200; open my $out_file, '>', "reversed"; syswrite( $out_file, $temp);` [download] and it give me all expected results byte for byte. :) also i should add that i am parsing the file using its hexadecimal representaion of a binary file and i honestly dont think you would even need to binmode any of these files and it doesnt need file::slurp. completely independant code teehee	[reply] [d/l]

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Re^3: Best way to read a file into memory and use normal operation on memory file?
by james28909 (Deacon) on Jul 16, 2014 at 23:17 UTC


open ( my $in_file, '<', "file" );
binmode( $in_file );


my $mem_file;
binmode( $mem_file );

my ( $buf, $data, $n, $bytes ); 

while (( $n = read $in_file, $data, 4096 ) != 0){
     $mem_file .= pack( "v*", unpack("n*", $data ));   
    $bytes+=$n;
    
}


open ( my $otherMem_file, '<', \$mem_file ); 
binmode( $otherMem_file );

seek $otherMem_file, 0x00, 0;
read $otherMem_file, my $temp, 0x1200;

open my $out_file, '>', "reversed";
syswrite( $out_file, $temp);
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[reply]
[d/l]