Re^2: Reading Binary files in Perl

Below is the structure or format of data in binary file: <structure> Offset Field Name size 0x0 magic_numbe 8 0x8 retry_count 1 0x9 number_record 1 0x10 dc_timestamp 8 <\structure> and the code is:

open(FH, "<DCdata.bin") or die "Can't open DCdata.bin file for reading
+!";
binmode(FH); 

while (<FH>)
{
    $index = 0;
    
    foreach $field_name (keys (%disk_structure)) {
        
        $value = read (FH, $buffer, ($field_name * 8), 0);
        print tell (FH);
        print "\n";
    }
    
    foreach $f_name (keys (%disk_structure_record)) {
        
        $value_record = read (FH, $buffer, ($f_name * 8), 0);
        #print tell (FH)\n;
    }
}

close(FILE);
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Re^3: Reading Binary files in Perl by BrowserUk (Patriarch) on Aug 25, 2010 at 13:16 UTC
If your file consists of 18 character records, then the easiest way to read it is to set the input record separator (`$/`) to a reference to the number of bytes per record: `$/ = \18;`. This causes readline() (`<FH>`) to read the file as a series of fixed length records. You can then unpack the fields within each record very easily: `#! perl -slw use strict; =comment Offset Field Name size 0x0 magic_numbe 8 0x8 retry_count 1 0x9 number_record 1 0x10 dc_timestamp 8 =cut open( FH, '<', DCdata.bin" ) or die "Can't open DCdata.bin file for reading!"; binmode(FH); $/ = \18; ## set record size while( <FH> ) { my( $magic, $retry, $recnum, $timestamp ) = unpack 'A8 C C A8', $_ +; ## Do something with the information?? } close FH;` [download] Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice. RIP an inspiration; A true Folk's Guy	[reply] [d/l] [select]
Re^3: Reading Binary files in Perl by Corion (Patriarch) on Aug 25, 2010 at 12:59 UTC
A hash is not ordered, so it makes no sense to read the (ordered) elements from a file in a `foreach` loop over the hash keys.	[reply] [d/l]