I am writing a program that uses system() to pass commands to the command interpreter. Is there a way to read the output that the commands produce? (1 Reply)
Greetings to all,
I would like to read input from a file and make duplications from it with Linux shell.
For e.g.
Input file
-----------
ABC
ABB
ABA
-------------------------------
Output file
------------
ABC
ABC
ABC
ABB
ABB (6 Replies)
Hi List,
How to read the output of a command executed from a script.
For ex.
sample_scritp.sh
-------------
useradd testuser1
password testuser1
....
.....
--------------
This prompts for "password", and "confirm password", for which i need to give the values from script.
Can... (4 Replies)
Can any body please explain the following df command to me:filesystem kbytes used avail capacity mounted on
/dev/root 6474195 2649052 3825143 41% /
/dev/stand 24097 5757 18340 24% /stand
/proc 0 0 0 ... (7 Replies)
I have a list of words that I want to grep in many files to see which ones have it and which ones dont.
in the text file I have all the words listed line by line, ex:
list.txt:
check
try this
word1
word2
open space
list ..
I want to grep each line one by one.
like I want it to... (7 Replies)
I stumbled across a somewhat strange behavior of tar and find no explanation for it: i was testing a DVD for read errors and thought to simply tar the content and direct the output to /dev/null:
tar -cvf - /my/mountpoint/*ts > /dev/null
This way i expected the system to read the complete... (4 Replies)
Hi there,
I got this situation at job. First i have a Perl script that connect to Oracle 10g and execute a package. That package execute severals transactions and must generate log about process status each interval of time.
What i'm doing now is saving the plsql package log in an auxiliar... (4 Replies)
Is it possible to read from the screen or standard output? If so, may I know how I can do this?
For example, I have an application running which prints out the following on the screen:
Starting tools from .image-tools...
imagecontrol_1: SECS/GEM-capable version is running
done
cindy@pgunix... (2 Replies)
I getting error as test1.sh: syntax error at line 3: `do' unexpected while i was trying to run below code..
What was going wrong here?
find /usr/tmp/SB/reports/ -type f -name *.rdf |read file;do
echo "Copying $file to /usr/tmp/SB1"
done (1 Reply)
I am writing one shell script in which there is one Java program call.
I want to stop execution of shell script ahead of java program if the java program returns 1 .
How to read that value of java program from OS ? (3 Replies)
Discussion started by: ParthThakkar
3 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)