Hi, I've written a shell function in bash that reads letters into an array, then outputs them in one column with:
for n in "${array}"; do
echo $n
done
I was wondering if anyone knew how i would transpose the letters that are output by the for loop. Right now my output is:
aabbcc... (4 Replies)
Hi,
I need to remove all lines from a file that do not start with numbers
For instance, if the first three characters on any line are not numbers, delete those lines
I've tried to do it with awk and it's not working, any ideas ?
Thanks (5 Replies)
I want to add letters A,B,C,… in front of every line of input while printing them out using PERL.
eg
A file is parsed as a cmd line arg and its context will be displayed as
A line1...
B line 2..
I tried this..but I want better and perfect solution!
!perl -p
my $counter;
BEGIN { $counter... (4 Replies)
Hello,
I am working with a perl script that tries to find the average "frequency" in which lines are duplicated. So far I've only managed to find the way to count how many times the lines are repeated, the code is as follows:
perl -ae'
my $filename= $ENV{'i'};
open (FILE, "$filename") or... (10 Replies)
I'm reading in numbers from a file and trying to add them together. Here is the code so far. I know the 1+2+3.... part is wrong. The file has five numbers in it with each number on its own line. The numbers are decimals if that matters. Thanks.
while read EachLine
do
echo $EachLine
done <... (6 Replies)
Hi,
Is there a tool somewhat parallel to rev, but which randomizes instead of reverses?
I've tried rl, but I can only get it to randomize words.
I was hoping for something like this
echo "hello" | ran
leolh
less simpler solutions are also welcome.
Sorry if the question is... (21 Replies)
Hi there,
first of all this is not homework...this is a new type of exercise for practicing vocabulary with my students.
I have a file consisting of two columns, separated by a tab, each line consisting of a word and its definition, separated by a line break.
What i need is to replace a... (15 Replies)
The awk below executes and is close (producing the first 4 columns in desired). However, when I add the sum of $7, I get nothing returned. Basically, I am trying to combine all the matching $4 in f1 and output them with the average of $7 in each match. Thank you :).
f1
... (2 Replies)
Discussion started by: cmccabe
2 Replies
LEARN ABOUT DEBIAN
devel::refcount
Devel::Refcount(3pm) User Contributed Perl Documentation Devel::Refcount(3pm)NAME
"Devel::Refcount" - obtain the REFCNT value of a referent
SYNOPSIS
use Devel::Refcount qw( refcount );
my $anon = [];
print "Anon ARRAY $anon has " . refcount($anon) . " reference
";
my $otherref = $anon;
print "Anon ARRAY $anon now has " . refcount($anon) . " references
";
DESCRIPTION
This module provides a single function which obtains the reference count of the object being pointed to by the passed reference value.
FUNCTIONS
$count = refcount($ref)
Returns the reference count of the object being pointed to by $ref.
COMPARISON WITH SvREFCNT
This function differs from "Devel::Peek::SvREFCNT" in that SvREFCNT() gives the reference count of the SV object itself that it is passed,
whereas refcount() gives the count of the object being pointed to. This allows it to give the count of any referent (i.e. ARRAY, HASH,
CODE, GLOB and Regexp types) as well.
Consider the following example program:
use Devel::Peek qw( SvREFCNT );
use Devel::Refcount qw( refcount );
sub printcount
{
my $name = shift;
printf "%30s has SvREFCNT=%d, refcount=%d
",
$name, SvREFCNT($_[0]), refcount($_[0]);
}
my $var = [];
printcount 'Initially, $var', $var;
my $othervar = $var;
printcount 'Before CODE ref, $var', $var;
printcount '$othervar', $othervar;
my $code = sub { undef $var };
printcount 'After CODE ref, $var', $var;
printcount '$othervar', $othervar;
This produces the output
Initially, $var has SvREFCNT=1, refcount=1
Before CODE ref, $var has SvREFCNT=1, refcount=2
$othervar has SvREFCNT=1, refcount=2
After CODE ref, $var has SvREFCNT=2, refcount=2
$othervar has SvREFCNT=1, refcount=2
Here, we see that SvREFCNT() counts the number of references to the SV object passed in as the scalar value - the $var or $othervar
respectively, whereas refcount() counts the number of reference values that point to the referent object - the anonymous ARRAY in this
case.
Before the CODE reference is constructed, both $var and $othervar have SvREFCNT() of 1, as they exist only in the current lexical pad. The
anonymous ARRAY has a refcount() of 2, because both $var and $othervar store a reference to it.
After the CODE reference is constructed, the $var variable now has an SvREFCNT() of 2, because it also appears in the lexical pad for the
new anonymous CODE block.
PURE-PERL FALLBACK
An XS implementation of this function is provided, and is used by default. If the XS library cannot be loaded, a fallback implementation in
pure perl using the "B" module is used instead. This will behave identically, but is much slower.
Rate pp xs
pp 225985/s -- -66%
xs 669570/s 196% --
SEE ALSO
o Test::Refcount - assert reference counts on objects
AUTHOR
Paul Evans <leonerd@leonerd.org.uk>
perl v5.14.2 2011-11-15 Devel::Refcount(3pm)