Re: What does ord mean?
On Mar 5, 2009, at 2:23 PM, Sherm Pendley wrote: On Thu, Mar 5, 2009 at 2:17 PM, Bill Stephenson bi...@perlhelp.com wrote: Okay, but now I'm curious. What does ord mean? (or do) It's an abbreviation of ordinal, and returns the position of the character within its charset - i.e., its ordinal value, as opposed to its text value. Thank you Sherm. I appreciate the clear descriptive answer. And thank you too, David. macbill% perldoc -f ord ord EXPR ord Returns the numeric (the native 8-bit encoding, like ASCII or EBCDIC, or Unicode) value of the first character of EXPR. If EXPR is omitted, uses $_. For the reverse, see chr. See perlunicode and encoding for more about Unicode. I like Sherm's explanation better than the Perl Docs though ;) Kindest Regards, -- Bill Stephenson
Re: What does ord mean?
Okay, but now I'm curious. What does ord mean? (or do) Kindest Regards, -- Bill
Re: What does ord mean?
On Thu, Mar 5, 2009 at 2:17 PM, Bill Stephenson bi...@perlhelp.com wrote: Okay, but now I'm curious. What does ord mean? (or do) It's an abbreviation of ordinal, and returns the position of the character within its charset - i.e., its ordinal value, as opposed to its text value. Perl's ord() function is encoding-aware, but *only* if Perl knows what encoding the passed-in string is using, which it doesn't by default. If you use utf8 at the top of your script, Perl knows that literal strings are utf-8 encoded, and flags them appropriately. Likewise if you use the :utf8 I/O layer to open a file handle, like this: open($fh, :utf8, $filename) or die Could not open $filename: $!; Bytes that are input from $fh are then assumed to be utf-8 encoded, and Perl sets an internal flag on the scalar to indicate this. That's what happened to the OP. When scalars do *not* have their utf-8 flag set, ord(), length(), and other builtin functions fall back to assuming that they're encoded with one byte per character. If that assumption is incorrect - as it is in the OP's case, where the character takes two bytes in utf-8 encoding - then the results from these functions will likewise be incorrect. sherm-- -- Cocoa programming in Perl: http://camelbones.sourceforge.net
Re: What does ord mean?
On Thu, Mar 05, 2009 at 01:17:38PM -0600, Bill Stephenson wrote: Okay, but now I'm curious. What does ord mean? (or do) perldoc -f ord -- David Cantrell | Nth greatest programmer in the world What profiteth a man, if he win a flame war, yet lose his cool?
Re: What does ord mean?
On Wed, Mar 4, 2009 at 19:58, Vic Norton v...@norton.name wrote:
I am confused. I can't figure out what ord does. For example I've pasted the
NO-BREAK-SPACE (00A0) between the quotation marks in the ord of the
following line.
print ord( ), \n;
When I run this line in a Perl script I get
194
What does this 194 mean? As far as I know A0 = 10x16 = 160. And 194
certainly can't be an octal numeral.
snip
I have a similar problem when copy and pasting in the terminal, but
when I write the characters to a file (or a pipe) it appears to do the
right thing:
perl -le 'print \x{A0}' | perl -nle 'print ord'
I assume the problem has to do with UNICODE vs UTF-8.
--
Chas. Owens
wonkden.net
The most important skill a programmer can have is the ability to read.
Re: What does ord mean?
NO-BREAK SPACE is 00A0, which in UTF-8 is xC2 xA0. Hex xC2 = Decimal 194. best, Paul Quoting Vic Norton v...@norton.name: I am confused. I can't figure out what ord does. For example I've pasted the NO-BREAK-SPACE (00A0) between the quotation marks in the ord of the following line. print ord( ), \n; When I run this line in a Perl script I get 194 What does this 194 mean? As far as I know A0 = 10x16 = 160. And 194 certainly can't be an octal numeral. Regards, Vic
Re: What does ord mean?
At 20:44 -0500 4/3/09, Paul G. Hackett wrote: NO-BREAK SPACE is 00A0, which in UTF-8 is xC2 xA0. Hex xC2 = Decimal 194. so #!/usr/bin/perl -w use strict; use utf8; print ord( ), \n; JD
