Visit Our UNIX and Linux User Community

Confusion in hash

Thread Tools Search this Thread
Top Forums Shell Programming and Scripting Confusion in hash
# 1  
Old 09-06-2013
Confusion in hash

Hi folks,

If a declare a direct hash , then the hash element works fine.
my %test = ("test",1);
print %test;
print "\n";

Here in the above, the name of the hash is predeclared...

Suppose now I need to create the hash elements dynamically in the for loop.

my ${$test}=("test",1);  ## assuming $test will be replaced by hash

But receiving an error message as below..

an't declare scalar dereference in "my" at line 3, near "}="
xecution of aborted due to compilation errors.

I have a requirement in which I need to create the hash elements in the loop based on some variables in array and I'm using "use strict" and "use warning pragmas" .

Could anyone please let me know how to create hash variables from the elements of array?

Thanks in advance ....

Last edited by scriptscript; 09-06-2013 at 08:41 AM..
# 2  
Old 09-06-2013
#! /usr/bin/perl

my @arr = ("key1", "key2", "key3");
my %hash = ();

foreach (@arr) {
    $hash{$_} = 1;

foreach (keys %hash) {
    print "$_ --> $hash{$_}\n";

Previous Thread | Next Thread
Test Your Knowledge in Computers #87
Difficulty: Easy
Windows 7 added PowerShell, a more powerful command-line shell and scripting language than the Command Prompt.
True or False?

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

Need to print hash of hash in table format

Hi, I have a hash of hash where it has name, activities and count i have data like this - $result->{$name}->{$activities} = $value; content of that are - name - robert tom cat peter activities - running, eating, sleeping , drinking, work i need to print output as below ... (3 Replies)
Discussion started by: asak
3 Replies

2. Shell Programming and Scripting

Dynamically parse BibTeX and create hash of hash

Hello gurus, Iam trying to parse following BibTex file (bibliography.bib): @book{Lee2000a, abstract = {Abstract goes here}, author = {Lee, Wenke and Stolfo, Salvatore J}, title = {{Data mining approaches for intrusion detection}}, year = {2000} } @article{Forrest1996, abstract =... (0 Replies)
Discussion started by: wakatana
0 Replies

3. Shell Programming and Scripting

Compare values of hashes of hash for n number of hash in perl without sorting.

Hi, I have an hashes of hash, where hash is dynamic, it can be n number of hash. i need to compare data_count values of all . my %result ( $abc => { 'data_count' => '10', 'ID' => 'ABC122', } $def => { 'data_count' => '20', 'ID' => 'defASe', ... (1 Reply)
Discussion started by: asak
1 Replies

4. Shell Programming and Scripting

Confusion with PS

Hello All, I have a problem in counting number of process getting run with my current script name.. Here it is ps -ef | grep $0 | grep -v grep This display just one line with the PID, PPID and other details when i print it in the script. But when I want to count the numbers in my... (11 Replies)
Discussion started by: sathyaonnuix
11 Replies

5. Shell Programming and Scripting

perl hash - using a range as a hash key.

Hi, In Perl, is it possible to use a range of numbers with '..' as a key in a hash? Something in like: %hash = ( '768..1536' => '1G', '1537..2560' => '2G' ); That is, the range operation is evaluated, and all members of the range are... (3 Replies)
Discussion started by: dsw
3 Replies

6. Shell Programming and Scripting

Perl Hash:Can not keep hash data in the same order that it was inserted

Can Someone explain me why even using Tie::IxHash I can not get the output data in the same order that it was inserted? See code below. #!/usr/bin/perl use warnings; use Tie::IxHash; use strict; tie (my %programs, "Tie::IxHash"); while (my $line = <DATA>) { chomp $line; my(... (1 Reply)
Discussion started by: jgfcoimbra
1 Replies

7. Shell Programming and Scripting

Assigning a hash to another hash key

Hello, I have a hash in hsh. I need to assign it to another hash globalHsh. I think the below statement does not work $globalHsh{$id} = %hsh; What is the right way to assign it? Thanks (3 Replies)
Discussion started by: rsanjay
3 Replies

8. Shell Programming and Scripting

Print Entire hash list (hash of hashes)

I have a script with dynamic hash of hashes , and I want to print the entire hash (with all other hashes). Itried to do it recursively by checking if the current key is a hash and if yes call the current function again with refference to the sub hash. Most of the printing seems to be OK but in... (1 Reply)
Discussion started by: Alalush
1 Replies

9. UNIX for Dummies Questions & Answers

'tr' confusion

Good day, everyone! Could anybody explain me the following situation. If I'm running similar script: Var="anna.kurnikova" Var2="Anna Kurn" echo $Var | tr -t "$Var" "$Var2" Why the output is : anna KurniKova instead of Anna Kurnikova? :confused: Thank you in advance for any... (2 Replies)
Discussion started by: Nafanja
2 Replies

10. Shell Programming and Scripting

Sed confusion

Hello all, I am trying to delete all the lines in a particular file having a pattern. The problem is that it has special characters and for some reason is not doing the job. For eg. src_file /home/test/filelist.txt :xxxx:ogog /home/test/RCH/ogogogg /home/test/RYHUJ/HHHH... (3 Replies)
Discussion started by: alfredo123
3 Replies

Featured Tech Videos