I'm writing a bash script to search the contents of a postfix log. To keep the script's output readable (since multiple lines from the log file need to be echo'ed) I am setting the IFS variable to an empty string so that the line breaks in my grep results are preserved. I am storing the results... (4 Replies)
Hello,
I'm confused (oh, yes). I'm running Linux at work. When I type 'echo $SHELL' I am told that I'm running tcsh. In /bin I note that both tcsh and bash are listed.
Question 1: Can I swap to run bash rather than tcsh and, if so, how will this affect my system? Is there any advantage to... (6 Replies)
hi all
i'm trying to get a script working upon connection with pppd
According to docu this happens ina clean environment with a couple of variables set, namely $1,$2,...
To be able to execute the statements i included a path statement but i think i'm running into trouble with the variables -... (6 Replies)
Hi,
can anyone help me with my scrip please. I wanted do following tasks:
1. List all the directory
2. A STDIN to ask user to enter a directory name from listed directories
3. command to check if the directory exists( or a command to validate if the user entered a valid directory name)
... (2 Replies)
Hey,
So I've run into a problem, due to my limited knowledge of Bash scripting.
Basically I've got a long script and I want to understand it before I even try and edit it. As long as I don't understand the script, I will not bother editing it.
Anyway, the following variable confuses me... (5 Replies)
Try to imagine a flag:
nnnnx
nnnxx
nnxxx
nxxxx
now imagine how it will output:
4 times the "n"and 1 times "x"
3 times "n"and" 2 times" x "
.. etc. ..
rhombus is the same only instead of "n" is there
gap "and " x "is a few times to form the correct shape
Can you help... (3 Replies)
same script:
1- i am using grep to find a string called: tinker panic 0 in a file /etc/ntp.conf
if the string is not there, i want to add the strings in /etc/ntp.conf file in the first line of the file. if not do nothing or exit.
2- also i want to add # in front of the following lines in... (0 Replies)
Hello,
I am new to Linux and studying to become a Unix System Admin. I am taking a course in which I was practicing creating a bash script to ping a particular IP address. The script can be found below:
#/bin/bash
echo "Enter the IP address"
read ip
if
then
ping -c 1 $ip
if ;... (3 Replies)
Hello All,
I have a file of ip addresses called activeips.txt
What I'm trying to do is run a simple bash script that has a loop in it. The loop is a cat of the IP addresses in the file.
The goal is to run 2 nmap commands to give me outputs where each address in the list has an OS... (11 Replies)
Discussion started by: Dirk_Pitt
11 Replies
LEARN ABOUT REDHAT
hash::util
Hash::Util(3pm) Perl Programmers Reference Guide Hash::Util(3pm)NAME
Hash::Util - A selection of general-utility hash subroutines
SYNOPSIS
use Hash::Util qw(lock_keys unlock_keys
lock_value unlock_value
lock_hash unlock_hash);
%hash = (foo => 42, bar => 23);
lock_keys(%hash);
lock_keys(%hash, @keyset);
unlock_keys(%hash);
lock_value (%hash, 'foo');
unlock_value(%hash, 'foo');
lock_hash (%hash);
unlock_hash(%hash);
DESCRIPTION
"Hash::Util" contains special functions for manipulating hashes that don't really warrant a keyword.
By default "Hash::Util" does not export anything.
Restricted hashes
5.8.0 introduces the ability to restrict a hash to a certain set of keys. No keys outside of this set can be added. It also introduces
the ability to lock an individual key so it cannot be deleted and the value cannot be changed.
This is intended to largely replace the deprecated pseudo-hashes.
lock_keys
unlock_keys
lock_keys(%hash);
lock_keys(%hash, @keys);
Restricts the given %hash's set of keys to @keys. If @keys is not given it restricts it to its current keyset. No more keys can be
added. delete() and exists() will still work, but will not alter the set of allowed keys. Note: the current implementation prevents the
hash from being bless()ed while it is in a locked state. Any attempt to do so will raise an exception. Of course you can still bless()
the hash before you call lock_keys() so this shouldn't be a problem.
unlock_keys(%hash);
Removes the restriction on the %hash's keyset.
lock_value
unlock_value
lock_value (%hash, $key);
unlock_value(%hash, $key);
Locks and unlocks an individual key of a hash. The value of a locked key cannot be changed.
%hash must have already been locked for this to have useful effect.
lock_hash
unlock_hash
lock_hash(%hash);
lock_hash() locks an entire hash, making all keys and values readonly. No value can be changed, no keys can be added or deleted.
unlock_hash(%hash);
unlock_hash() does the opposite of lock_hash(). All keys and values are made read/write. All values can be changed and keys can be
added and deleted.
AUTHOR
Michael G Schwern <schwern@pobox.com> on top of code by Nick Ing-Simmons and Jeffrey Friedl.
SEE ALSO
Scalar::Util, List::Util, Hash::Util
perl v5.8.0 2002-06-01 Hash::Util(3pm)