How may I set a bit or change (10100101 to 10100111)?

unixhome has asked for the wisdom of the Perl Monks concerning the following question:

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Re: How may I set a bit or change (10100101 to 10100111)? by GrandFather (Saint) on Jun 15, 2006 at 20:35 UTC
It depends what you actually want to achieve - Set the bit: $value \|= 0x02; Toggle the bit: $value ^= 02; Increment the bit: $value += 0b00000010; Note that the constants are given as hex, octal and binary for the successive samples. For completeness it should be noted that `$value &= ~2` resets the bit. DWIM is Perl's answer to Gödel	[reply] [d/l]
Re: How may I set a bit or change (10100101 to 10100111)? by philcrow (Priest) on Jun 15, 2006 at 20:36 UTC
You can mask and work on bits in a manner similar to C. That is, to set a bit OR your number with a number that has the bit set. Use \| for or, & and, etc.: `my $bit_set = $old_number \| 0x2;` [download] All of those are borrowed from C notation. If your ints are too big look at Math::BigInt, which I think is standard, but I could be wrong. Phil	[reply] [d/l]
Re: How may I set a bit or change (10100101 to 10100111)? by TGI (Parson) on Jun 15, 2006 at 21:00 UTC
You can also use unpack(), pack() and vec() to work with binary data. merlyn just wrote an article about pack. TGI says moo	[reply]
Re: How may I set a bit or change (10100101 to 10100111)? by Joost (Canon) on Jun 15, 2006 at 20:59 UTC
You can do bit-wise or using the \| operator: `my $a6 = 0b10100101; my $a7 = $a6 \| 0b0000010; printf "dec: $a7, hex: %x\n",$a7` [download] see also perlop's section on bitwise or update: ignore the variable names :-) "What should it profit a man, if he should win a flame war, yet lose his cool?"	[reply] [d/l]
Re^2: How may I set a bit or change (10100101 to 10100111)? by GrandFather (Saint) on Jun 15, 2006 at 21:18 UTC
`my $a6 = 0b10100101;` is a little misleading as the hex value is actually 0xA5. Oring 2 with 0xA6 leaves the value unchanged by the way. DWIM is Perl's answer to Gödel	[reply] [d/l]
Re^3: How may I set a bit or change (10100101 to 10100111)? by Joost (Canon) on Jun 15, 2006 at 21:19 UTC
Erm.. oops :-) "What should it profit a man, if he should win a flame war, yet lose his cool?"	[reply]