I'm just getting started to lean C and I'm using Ubuntu today I found a tutorial at this site: http://einstein.drexel.edu/courses/CompPhys/General/C_basics/c_tutorial.html and I got an error after compiling the fist code:
#include < stdio.h>
void main()
{
printf("\nHello World\n");
} ... (9 Replies)
Ok here is the deal, I have a command given to me by some systems guy who I cannot get ahold of on the weekend without paying him alot of money to help me. I need to get this done before Monday as I am just getting pummeled by DOS attacks. The comand given was....
netstat -ntu | awk '{print... (1 Reply)
I have a file with 3 digit numbers in it formatted as such:
123
065
321
How would I go about seeing if each number is less than 100 and if so outputting it to another file
Yes, I am a bit of a noob. I have tried with grep but I don't think it'll work.
Any general direction would be... (6 Replies)
I dont know what I am doing wrong but I would like to redirect the stderr output to a file?
the specific command is this
time wget http://www.something.com/somefile.bin
All I want to see is time's output which is stderr so I can see how long the file download took. I've tried redirecting... (2 Replies)
First time poster here and I'm pretty much a total noob with UNIX and Perl. So please bear with me.
With Perl, I'm trying to fill an array with data that is in a CSV file. I would like to fill the array with only one of the columns in the CSV file.
I have a file called data.csv:
... (2 Replies)
What is this script meant to do? How do I make it executable and how do i run it? I am trying to understand what the script is doing and how it is doing it... need a little advice. Here is is..
if
then
list=`w | grep $user | cut -c19-30`
if
then
echo "The user $user is... (2 Replies)
Hello,
I am new to shell scripting and i am trying to figure why is this not working with else statement.
I am searching for every directory in that DIR i am in, however the "else" seems to be triggered whenever the run the script..
Much thanks in advance!
#!/bin/shell
for item in... (3 Replies)
I'm having some difficulty with convincing Expect to do what I need..
I have a loop that waits for input, a specific phrase of text followed by a single word. I need Expect to capture that word following the specific phrase. It should then store the word in a variable.
I'm fairly sure it's... (6 Replies)
I am trying to work on a script to grab the UTC time from a website
So far I was able to cobble this together.
curl -s --head web-url | grep ^Date: | sed 's/Date: //g'
Which gives me the result I need.
Wed, 06 Dec 2017 21:43:50 GMT
What I need to is extract the 21:43:50 and convert... (4 Replies)
Discussion started by: allisterB
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)