Extracting a bit of a scalar variable
Hi All, I am newbie to PERL.I think this is a very simple question to ask. Is there any way to print a particular bit of a digit after converting to binary form. Thanks in Advance, Praveena -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/ http://learn.perl.org/first-response
Re: Extracting a bit of a scalar variable
Hello Praveena, I recommend you to use pack and unpack function. I believe you can use this to convert the digit to binary and also extract the digit of your choice from the result. perldoc -f pack type this command at your linux console if any to get the help on pack. Regards Nishanth --- Praveena Vittal [EMAIL PROTECTED] wrote: Hi All, I am newbie to PERL.I think this is a very simple question to ask. Is there any way to print a particular bit of a digit after converting to binary form. Thanks in Advance, Praveena -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/ http://learn.perl.org/first-response __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/ http://learn.perl.org/first-response
Re: Extracting a bit of a scalar variable
On Apr 21, 2006, at 20:59, Praveena Vittal wrote: Is there any way to print a particular bit of a digit after converting to binary form. That can be easily done with substr y sprintf, this would take the second bit of 7 written in base 2: % perl -wle 'print substr sprintf(%b, 7), -2, 1' 1 That's quite readable, but if efficiency is an issue then pack/unpack might be better, it had to be measured in any case. -- fxn -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/ http://learn.perl.org/first-response
Re: Extracting a bit of a scalar variable
Praveena Vittal schreef:
I am newbie to PERL.
ITYM: Perl.
I think this is a very simple question to ask.
Well, let's see.
Is there any way to print a particular bit of a digit after converting
to binary form.
Why convert anything to binary first, if you can use
$var (1 $bitpos)?
$ echo 200
| perl -nle 'printf \n b %5d\n-- -\n, $_;
for $b (0 .. 15)
{ printf %2d %5s\n,
$b, $_ ($p = 1 $b) ? $p : }'
$ echo 3276767676
| perl -nle 'printf \n b %10d\n-- --\n, $_;
for $b (0 .. 31)
{ printf %2d %10s\n,
$b, $_ ($p = 1 $b) ? $p : }'
For larger integers, look for bigint on CPAN.
--
Affijn, Ruud
Gewoon is een tijger.
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RE: Extracting a bit of a scalar variable
Original Message-
From: Dr.Ruud [mailto:[EMAIL PROTECTED]
Sent: Friday, April 21, 2006 9:19 AM
To: beginners@perl.org
Subject: Re: Extracting a bit of a scalar variable
Praveena Vittal schreef:
I am newbie to PERL.
ITYM: Perl.
I think this is a very simple question to ask.
Well, let's see.
Is there any way to print a particular bit of a digit after converting
to binary form.
Why convert anything to binary first, if you can use
$var (1 $bitpos)?
$ echo 200
| perl -nle 'printf \n b %5d\n-- -\n, $_;
for $b (0 .. 15)
{ printf %2d %5s\n,
$b, $_ ($p = 1 $b) ? $p : }'
snip
--
Affijn, Ruud
**
b200
-- -
0
1
2
3 8
4
5
6 64
7128
8
9
10
11
12
13
14
15
So what does this output tell me in English, that the decimal number 200
is composed of ???
Derek Bellner Smith
Unix Systems Engineer
Cardinal Health Dublin, Ohio
[EMAIL PROTECTED]
Working together. For life.(sm)
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RE: Extracting a bit of a scalar variable
-Original Message-
From: Smith, Derek
Sent: Friday, April 21, 2006 10:22 AM
To: Perl Beginners
Subject: RE: Extracting a bit of a scalar variable
Original Message-
From: Dr.Ruud [mailto:[EMAIL PROTECTED]
Sent: Friday, April 21, 2006 9:19 AM
To: beginners@perl.org
Subject: Re: Extracting a bit of a scalar variable
Praveena Vittal schreef:
I am newbie to PERL.
ITYM: Perl.
I think this is a very simple question to ask.
Well, let's see.
Is there any way to print a particular bit of a digit after converting
to binary form.
Why convert anything to binary first, if you can use
$var (1 $bitpos)?
$ echo 200
| perl -nle 'printf \n b %5d\n-- -\n, $_;
for $b (0 .. 15)
{ printf %2d %5s\n,
$b, $_ ($p = 1 $b) ? $p : }'
snip
--
Affijn, Ruud
**
b200
-- -
0
1
2
3 8
4
5
6 64
7128
8
9
10
11
12
13
14
15
So what does this output tell me in English, that the decimal number 200
is composed of ???
Was the above a silly question? I have not seen a reponse. I do
understand what this $var (1 $bitpos)? is doing, nor do I
understand what the output means?
Please explain,
Thx
Derek
Working together. For life.(sm)
_
This message is for the designated recipient only and may contain privileged,
proprietary, or otherwise private information. If you have received it in
error, please notify the sender immediately and delete the original. Any other
use of the email by you is prohibited.
Dansk - Deutsch - Espanol - Francais - Italiano - Japanese - Nederlands - Norsk
- Portuguese - Svenska: www.cardinalhealth.com/legal/email
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Re: Extracting a bit of a scalar variable
On Friday 21 April 2006 10:15, Smith, Derek wrote:
-Original Message-
From: Smith, Derek
Sent: Friday, April 21, 2006 10:22 AM
To: Perl Beginners
Subject: RE: Extracting a bit of a scalar variable
Original Message-
From: Dr.Ruud [mailto:[EMAIL PROTECTED]
Sent: Friday, April 21, 2006 9:19 AM
To: beginners@perl.org
Subject: Re: Extracting a bit of a scalar variable
Praveena Vittal schreef:
I am newbie to PERL.
ITYM: Perl.
I think this is a very simple question to ask.
Well, let's see.
Is there any way to print a particular bit of a digit after converting
to binary form.
Why convert anything to binary first, if you can use
$var (1 $bitpos)?
$ echo 200
| perl -nle 'printf \n b %5d\n-- -\n, $_;
for $b (0 .. 15)
{ printf %2d %5s\n,
$b, $_ ($p = 1 $b) ? $p : }'
snip
--
Affijn, Ruud
**
b200
-- -
0
1
2
3 8
4
5
6 64
7128
8
9
10
11
12
13
14
15
So what does this output tell me in English, that the decimal number 200
is composed of ???
It tells me that in the binary representation of the decimal number 200, bits
4, 7, and 8 are set. It even makes it easy for me to check by supplying me
with the decimal values of at those positions.
Decimal: 200
Binary: __1100_1000
Hex: 00C8
128+64 +8 = 200
Was the above a silly question? I have not seen a reponse. I do
understand what this $var (1 $bitpos)? is doing, nor do I
understand what the output means?
Bit Manipulation
perldoc perlop
Please explain,
Thx
Derek
Working together. For life.(sm)
_
This message is for the designated recipient only and may contain
privileged, proprietary, or otherwise private information. If you have
received it in error, please notify the sender immediately and delete the
original. Any other use of the email by you is prohibited.
Dansk - Deutsch - Espanol - Francais - Italiano - Japanese - Nederlands -
Norsk - Portuguese - Svenska: www.cardinalhealth.com/legal/email
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