Hi ,
Can anybody explain how this perl one liner works..
It is to test whether the number is prime or not
perl -le 'print "PRIME" if (1 x shift) !~ /^(11+)\1+$/' 19
Thanks in advance
Shihab (2 Replies)
Thanks for giving your time and effort to answer questions and helping newbies like me understand awk.
I have a huge file, millions of lines, so perl takes quite a bit of time, I'd like to convert these perl one liners to awk.
Basically I'd like all lines with ISA sandwiched between... (9 Replies)
Hi, I'm writing a ksh script and trying to use an awk / sed / or perl one-liner to remove the last 4 characters of a line in a file if it begins with a period.
Here is the contents of the file... the column in which I want to remove the last 4 characters is the last column. ($6 in awk). I've... (10 Replies)
hello,
I want to replace awk with a perl one liner in unix.
i use in awk REGEX and FS ( field separator) because
awk syntaxes in different unix os versions have not the same behaviour.
Awk, Nawk and GNU Awk Cheat Sheet - good coders code, great reuse
i have a file named "file" and want... (5 Replies)
Hello experts,
I'm stuck with this script for three days now. Here's what i need.
I need to split a large delimited (,) file into 2 files based on the value present in the last field.
Samp: Something.csv
bca,adc,asdf,123,12C
bca,adc,asdf,123,13C
def,adc,asdf,123,12A
I need this split... (6 Replies)
Dear Unix Forums,
I am hoping you can help me with a pattern matching problem.
What am I trying to do?
I want to replace multiple lines of a text file (that match a multi-line pattern) with a single line of text. These patterns can span several lines and do not always have the same number of... (10 Replies)
hi,
I am using PERL one liner for oracle database connection as :
$PERL -e "use DBI; DBI->connect(qw(DBI:Oracle:SID user passwd));"
is there a way to append select statement to this connection ? i.e. DB connection and select stmt in one line ?
how to do sysdba connection using one lines... (1 Reply)
Hello,
I'm looking to check only the first line of a file to see if it is a format string, like
# -*- coding: utf-8; mode: tcl; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -\*- vim:fenc=utf-8:ft=tcl:et:sw=2:ts=2:sts=2if the first line is anything else, insert the above string.
I'd... (3 Replies)
Hi
I want to replace time stamp in the following line
PROCNAME.Merge.exchMon.CODE.T_QSTART 08:45 read
assuming the new time stamp is 09:45 ; the line is getting replaced as below
:45 read
I'm trying to use the perl one liner in bash script
perl -pi... (4 Replies)
Discussion started by: charlie87
4 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)