On liner STDIN

[malpa]

Hi

Im decoding a binary file, this file has this structure

HEx
bc 08 00 50 00 31 48 27 20 83 ff ff ff ff 03 87 40 55 90 20 11 07 31 05 04 29 00 00 02 75 00 00 00 00 01 21 00 16
bc 08 00 50 00 31 34 56 93 90 ff ff ff ff 03 87 40 55 90 20 11 07 31 05 09 00 00 00 00 30 00 00 00 00 01 21 00 16

I decode the file and count the registers using this programm

perl myprogramm <file> | wc -l

18916 registers.


#!/usr/bin/perl
$file1 = $ARGV[0];
open(FILE1,"<$file1") or die "Input file: Cannot open file\n\n";
$[=1;
seek FILE1,0 ,0;
my $e=0;
while ( sysread (FILE1, my $rec,1) ) {
my @reg3 = unpack ("H2",$rec);
if ( $reg3[1] eq "bc" ){
my $ptr = tell ( FILE1 );
#print $ptr."\n";
seek FILE1,-1,1;
sysread (FILE1, my $rec,38);
@reg3 = unpack ("H2 H2 H2 H2 H2 H2H2H2H2H2 H2H2H2H2H2H2H2H2H2 H2 H2H2H2H2H2H2 H2H2H2H2 H2H2H2H2 H2H2 H2H2",$rec);
for ( $i=1; $i<=38;$i++){
print $reg3[$i]." ";
}
print "\n";
}
}
close(FILE1);


but If a try to run the same programm in one line, only print half the registers.

cat <file> | perl myprogram2.pl | wc -l

9640 registers.

myprogramm2.pl

#!/usr/bin/perl
$[=1;
while ( sysread (STDIN, my $rec,1) ) {
my $val = unpack ("H2",$rec);
if ( $val eq "bc" ){
seek STDIN,-1,1;
sysread (STDIN, $rec,38);
@reg = unpack ("H2 H2 H2 H2 H2 H2H2H2H2H2 H2H2H2H2H2H2H2H2H2 H2 H2H2H2H2H2H2 H2H2H2H2 H2H2H2H2 H2H2 H2H2",$rec);
for ( $i=1; $i<=38;$i++){
print $reg[$i]." ";
}
print "\n";
}
}


08 00 50 00 31 48 27 20 83 ff ff ff ff 03 87 40 55 90 20 11 07 31 05 04 29 00 00 02 75 00 00 00 00 01 21 00 16 bc
08 00 50 00 ff 87 61 17 26 ff ff ff ff ff f7 40 28 01 20 11 07 31 05 09 51 00 00 00 13 00 00 00 00 00 20 00 95 bc


I appreciate any suggestion

Thanks
malpa

 

[Annihilannic]

Without delving too deeply... you cannot seek on a pipe (which is what you are reading when you pipe data in from STDIN), but you can on a file. I suspect that's your problem.

Annihilannic.