Hi all,
I need to extract some lines from a file based on a condition. For ex:
My file will contain 50 lines and i need to extract line which has "File" in it and then the line which has "date" in it. Which command will be the most efficient way to do it. I have tried two ways
1.... (1 Reply)
i want to extract lines 5 and 7 from a txt file which contains nearly 20 entries how to do it
also i want to check whether the 42nd character is 'S' in that line
suggestions welcome (4 Replies)
Hi All,
Please help me out in fllowing problem.
I have text file which contains the data in following format.
Contents of file.txt are
setregid02
Test that setregid() fails and sets the proper errno values when a
non-root user attemps to change the real or effective... (2 Replies)
Hi All,
I would like to extract from a text file m lines skipping n lines after a string occurrency. Is it possible with grep?
e.g.
qqq
ww
eee
rrr
ttt
yyy
uuu
I want to print 2 lines skipping 1 line after the string 'ww'
result would be
rrr
ttt (2 Replies)
Hi,
We have a file where we need to extract the lines of a file based on the first three characters of every line in that file.
Eg:
RAM hill station
SAM student
RAM rose
SAM apple
RAM india
SAM australia
RAM happy
RAM heaven
SAM smile
RAM glow
So, all the lines that start... (5 Replies)
Hi,
I have one file, say file 1, that has data like below where 19900107 is the date,
19900107 12 144 129 0.7380047
19900108 12 168 129 0.3149017
19900109 12 192 129 3.2766666E-02
... (3 Replies)
consider i have two files
cat onlyviews1.sql
CREATE VIEW V11
AS
SELECT id,
name,
FROM
etc etc
WHERE etc etc;
CREATE VIEW V22
AS
SELECT id,
name,
FROM
etc etc
WHERE etc etc;
CREATE VIEW V33
AS (10 Replies)
Hi,
If I have a file of something like
@hg19_gold_AL122127.6-131160
GCTTCATCATGCATGGATAGGCTGGCGCCTTTCCTGAGGCCATATGCCGATGGATATG
@hg19_gold_AL122127.6-131159
CTTTAATATTTCCGCCACCATCCTGAGTGAATCCCAGCAAGGACAGTCTTTGGGGATT
@hg19_gold_AL122127.6-131158... (4 Replies)
Discussion started by: jyu429
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)