Hi,
I am having a trivial doubt. Please see the below pipeline code sequence.
command1 | (command 2; commend 3)
I am aware that the command that follows pipe will run in the sub shell by the Unix kernel. But how about here? Since these set of commands are grouped under "parantheses", will... (6 Replies)
I have a cron on a Linux server that isn't executing properly.
CRON (with specific info replaced):
MAILTO=emailaddress@server.com
*/2 * * * * python /data/site/cron.py
OUTPUT:
python: can't open file '/data/site/cron.py
': No such file or directoryAdditional info
- The python path is... (3 Replies)
Hi Guys,
Just a question about subprocesses.. Lately one of our servers has started to throw out the following error:
SYSTEM ERROR: Too many subprocesses, cannot fork. Errno=12
We've already increased the threshold twice. Its now up to 8000 and the swap space has also been increased. We... (6 Replies)
Hi,
I am trying to run a shell script using subprocess in python.
I can run simple script with arguments using subprocess.But I am not able to embed xterm in subrocess command.
#!/usr/bin/python
import subprocess
subprocess.call()
Above code gives me error.
Please help me in... (2 Replies)
Hi guys,
I'm learning python and perl and i was trying to run from python a perl script using the subprocess module.
I have an issue that i don't understand regarding this.
I run this code:
#!/usr/bin/python
import subprocess
p2 = subprocess.Popen(,stdout=subprocess.PIPE)
output2 =... (2 Replies)
Greetings!
I set up a basic threading specimen which does the job:#!/usr/bin/python
import threading
class a(threading.Thread):
def __init__(self):
threading.Thread.__init__(self)
def run(self):
print("thread a finished")
class b(threading.Thread):
... (0 Replies)
Hi Experts,
Good morning.
I am trying to convert my hello.py to hello .exe file.
I followed the steps as mentioned in the documentation but getting errors in the end. Please help.
What I did as below--
Created hello.py file
print ("Hello world!")
raw_input('')
Then... (0 Replies)
I have a string like below
Note: I have have a single to any number of comma "," seperated string assigned to jdbc_trgt variable.
I need to split jdbc_trgt using comma(,) as the delimiter.
I tried the below but it fails as i dont know how can i read each split string iterately.
for... (4 Replies)
Discussion started by: mohtashims
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)