Michael Brader wrote:
On 07/16/2012 04:05 PM, De-Jian Zhao wrote:
I want to change the record separator in a Perl one liner with ">" as
the separator. However, I tried without success.
The perlrun document
(http://perldoc.perl.org/perlrun.html#Command-Switches) says that*
"***-0*[/octal/hexadecimal/] * specifies the input record separator
(|$/| ) as an octal or hexadecimal number. *"
*When I tried to get the octal/hexadecimal code of ">" with oct(">")
and hex(">"), I got "0". I used this number and it did not work the
way I wanted (perl -00 -ne 'print if /AAAA/' test.seq ).
From 'perldoc -f oct'
...
oct Interprets EXPR as an octal string and returns the corresponding
value.
...
To go the other way (produce a
number in octal), use sprintf() or printf():
$perms = (stat("filename"))[2] & 07777;
$oct_perms = sprintf "%lo", $perms;
So it is used for converting a string into an octal value. But we can go
the other way with printf and ord:
perl -e 'printf "%lo\n", ord(q{>})'
76
Now perl will leave the input record separator on the string, but we can
take that off with chop:
echo 'AAAA>BBBB>CCCC' | perl -0076 -nE 'chop,say if /AAAA/'
AAAA
Better to use chomp (the -l switch) instead of chop:
echo 'AAAA>BBBB>CCCC' | perl -0076nlE 'say if /AAAA/'
TIMTOWTDI of course, and you could also do it like this:
echo 'AAAA>BBBB>CCCC' | perl -nE 'for (split />/) { say if /AAAA/ }'
AAAA
echo 'AAAA>BBBB>CCCC' | perl -F> -naE '/AAAA/ && say for @F'
:-)
John
--
Any intelligent fool can make things bigger and
more complex... It takes a touch of genius -
and a lot of courage to move in the opposite
direction. -- Albert Einstein
--
To unsubscribe, e-mail: beginners-unsubscr...@perl.org
For additional commands, e-mail: beginners-h...@perl.org
http://learn.perl.org/
