Re^4: perl unpack and matching the unpacked data

ok im going to go ahead and give it another shot, and this time i will write it in this format:

if ( $data eq "8000" || $data eq "0080" ) {
    $tid = "TEST";
    $buf = "TEST SYSTEM";
} 
elsif ( $data eq "8000" || $data eq "0080" ) {
    $tid = "TOOL";
    $buf = "TOOL SYSTEM";
}
elsif.....
[download]

i didnt try it exactly like this. what i tried was actually:

elsif ( $data eq "8000" || "0080" ) {
     $tid = .....;
}
[download]

i think that will work. i will come back and update the thread when i come to a conclusion.

Comment on Re^4: perl unpack and matching the unpacked data Select or Download Code

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Re^5: perl unpack and matching the unpacked data by AnomalousMonk (Archbishop) on Jul 18, 2014 at 01:10 UTC
... what i tried was actually: `elsif ( $data eq "8000" \|\| "0080" ) { $tid = .....; }` [download] As you discovered, this syntax doesn't work — at least, not the way you expected: the truth value of the expression `$data eq '8000'` is logical-ored with `'8000'`. Again, let Perl help you: `c:\@Work\Perl\monks>perl -wMstrict -MO=Deparse,-p -le "my $data = '8000'; ;; if ($data eq '8000' \|\| '0080') { print 'yes'; }; " BEGIN { $^W = 1; } BEGIN { $/ = "\n"; $\ = "\n"; } use strict 'refs'; (my $data = '8000'); if ((($data eq '8000') or '0080')) { print('yes'); } -e syntax OK` [download]	[reply] [d/l] [select]
Re^5: perl unpack and matching the unpacked data by Laurent_R (Canon) on Jul 18, 2014 at 06:24 UTC
`if ( $data eq "8000" \|\| $data eq "0080" ) { $tid = "TEST"; $buf = "TEST SYSTEM"; } elsif ...` [download] and `if ( $data eq "8000" or $data eq "0080" ) { $tid = "TEST"; $buf = "TEST SYSTEM"; } elsif ...` [download] are strictly equivalent (in this case). As others have commented, \|\| and or have different precedence, but that doens not make any difference here. Personally I prefer to use the lower precedence `or` when grooping to Boolean expresions, but that's a matter of taste and that's debatable. `if ( $data eq "8000" \|\| "0080" )` [download] on the other hand is just wrong, although the compiler will assign a meaning to it. It is wrong in the sense that it is simply not doing what you intend: this is saying : if $data is "8000" or if "0080", which will be always true, because "0080" is a true value. So fix it as you said (with either of the two syntaxes shown at the beginning of this post) and your program should work properly.	[reply] [d/l] [select]