I'm trying to answer the following question about file permissions in Unix. Consider a file with the following permissions:
rwx---r--
I am not the owner of this file, but I am a member of the group of this file.
My question is: do I have read access to this file?
I thought... (3 Replies)
netjk@rediffmail.com
I have a Shell Script (wrapper) that gathers parameters and invoke a base script (lets say B1). I have set the permission for this script as 711 (execute for everyone, group). When a user from another group try to execute the script, permission is denied (Cannot open file..)... (1 Reply)
Hi all,
ok here is my problem, my program below is reading lines in from a file (one at a time) and printing them out. my problem is that i want it to only print out 3 lines at a time on the screen, but the "read value" command in my code isnt working. Whats wrong? & what can i do to get this... (1 Reply)
Hello all,
I need to write a little unix script to do some work on multiple files. I need to enter the filenames from the command line (scriptname <filename> <filename>. I have written the code to do double spacing, and some line numbering but it does not take multiple files from the command... (1 Reply)
Hi,
I am fairly new to Unix. My school computers have only UNIX installed on them, and I wish to use them to do some parallel computing. To do so, I need to transfer the files from my Windows computer to my Unix account on a different computer.
I am using the SSH login with the Putty client.... (2 Replies)
Dear all,
I got some questions abt how does the Unix kernel work
with the work with the other components. (step by step)
Can any body tell me some info abt that? if can provide
a example for each question that gonna be perfect!
Thank you!!!
1. How file management system work together... (2 Replies)
Hello all,
I am trying to write a simple script that will parse through a text/properties file and check a couple of if statements.
Here is what I have so far:
FILENAME=$1
while read line
do
echo $line
done < $FILENAME
When I call ./simple.sh testfile.txt I recieve a file or... (7 Replies)
I am trying to FTP files from windows to UNIX (IBM AIX). After having sent the files to unix server. Permisssion of the files becomes 640 (rw-r-----). I have to manually login to unix and do chmod 644 on the folder to give it permission. Is it possible that the files automaically be set to 644 on... (2 Replies)
Hi ,
I just write a simple function to read the file line by line.
But when I run it it says out of memory.
I am not sure about the root cause, Can someone help me out of this?
:D
#! /usr/bin/perl
use strict;
sub checkAPs{
my $NDPDir = "/home/eweiqqu/NCB/NDP_files/";
... (1 Reply)
Experts: i want to change this permission back to the way it was:
Initial:
drwxr-xr-x 8 oracle oinstall 4096 Jun 5 15:21 oracle
Now: drwxr-xr-x 8 oracle oinstall 4096 Jun 5 15:21 oracle
drwsr-sr-x 8 oracle oinstall 4096 Jun 5 15:21 oracle
Now I want to switch it back to ... (2 Replies)
Discussion started by: sumang24
2 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)