I am trying to using pipe (|) with ! (not) operator to list all the other files except the latest two and I am using the following command.
$ ls -ltr *.lst|!(tail -2)
ksh: 20050211180252.lst: cannot execute
but it is trying to execute the file returned by tail -2. I am able to do that in 4... (8 Replies)
Hi ,
I have found a interesting thing about tail command:
when I tried to use 'tail -1 *' to look at every file with the current derectory, I only got one line of result of one file.
But if I use 'head -1 *', I would get multiple lines.
Is there a way to do get multiple lines with 'tail -1 *'... (3 Replies)
I was wondering how can I do this
I have file myfile.txt
wc -l is: 5 000 000
I have to remove first 1 000 000 lines from header..
I tryed with tail -4000000 myfile.txt>newfile.txt
but it does not work...
any help?? (2 Replies)
HI i have to copy the last 5000 lines form a log file and copy the same in the same file .overwriting the same log file.
ex: tail -5000 testfile1 > testfile2
cat testfile2
mv tesftfile2 testfile1
will produce the correct result.but i want to have this done in one line???? (4 Replies)
Please help with the following command
tail -f /appdata/logs/alert_audit517.txt | grep "Sep 02"
The problem I have is with the file name "alert_audit517.txt". The 3 digit number at the end of the file name changes, so I need the file name to use a wildcard. Ive tried alert_audit***.txt, but... (5 Replies)
Hi,
In my home directory, there are so many files. i tried to get the lastly created file by following command.
file=`ls -lrt MXOfiles* | tail -1`
As there are so many files, it displays
"$ : 0403-027 The parameter list is too long."
Can someone tell me how can i get the recent file... (1 Reply)
Hi does anyone know how to create a file using the tail command? My book has this file I need to create and it says to use the tail command and that it is possible but I have no idea. Thanks. (4 Replies)
Use and complete the template provided. The entire template must be completed. If you don't, your post may be deleted!
1. The problem statement, all variables and given/known data:
Devise a chain of filters using some or all of the following programs pr, cut, cat, tail to
display a numbered... (8 Replies)
Hi,
I want to do file format using awk script, for that i wan to use 'tail'. Here is the scenario. I will be having set of files in a directory. Those files i need to write to another directory with same file name, but while writing the file to out directory, i need to write the last line as... (3 Replies)
Hi Team,
Can anyone help me here:
I have to access server logs via putty and these logs file is a trailing file (continously updating) with ERROR and WARNINGS... I need to know if I can pull this trailing file to a local drive so that I can do some higlighting on some keywords through Notepad... (13 Replies)
Discussion started by: jitensetia
13 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)