Using "set -u" can be nasty. It's a way to force you to declare all your variables before using them, which is good programming practice. Referencing any unset variable will force the script to exit.
Unfortuantely this means you cannot even test if a variable is set without making the shell blow up. In these cases I usually see some piece of code framed by "set +u" and "set -u" again, which is ugly. If you have "set -u" active, then you should reference any external variables of unknown state like this:
The shell uses the above syntax to return a default value when "unknownvar" is not set or is null. Since the default value is omited, it returns null but does NOT cause the shell to exit.
Hi,
i'm programming on /bin/csh and i need to get the number extracted by this:
set ppl_kn = $(awk '{ field = $6 } ; END{ print field }' < ppl_LM_kn.ppl )
and the output is: "Illegal variable name."
Please anyone can help me what's wrong?
Thanks in advance (2 Replies)
Hi,
Please clarify what is the difference between "env" and "set" command.
I guess set will display the system variables and user defined variables.
Thanks
Sweta (1 Reply)
Hi Friends,
Can any of you explain me about the below line of code?
mn_code=`env|grep "..mn"|awk -F"=" '{print $2}'`
Im not able to understand, what exactly it is doing :confused:
Any help would be useful for me.
Lokesha (4 Replies)
Hi,
I have line in input file as below:
3G_CENTRAL;INDONESIA_(M)_TELKOMSEL;SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL
My expected output for line in the file must be :
"1-Radon1-cMOC_deg"|"LDIndex"|"3G_CENTRAL|INDONESIA_(M)_TELKOMSEL"|LAST|"SPECIAL_WORLD_GRP_7_FA_2_TELKOMSEL"
Can someone... (7 Replies)
How to use "mailx" command to do e-mail reading the input file containing email address, where column 1 has name and column 2 containing “To” e-mail address
and column 3 contains “cc” e-mail address to include with same email.
Sample input file, email.txt
Below is an sample code where... (2 Replies)
Look at the following data file(cou.data) which has four fields separated by tab.
Four fields are country name, land area, population, continent where it belongs.
As for country name or continent name which has two words, two words are separated by space.
(Data are not accurately... (1 Reply)
Hello.
System : opensuse leap 42.3
I have a bash script that build a text file.
I would like the last command doing :
print_cmd -o page-left=43 -o page-right=22 -o page-top=28 -o page-bottom=43 -o font=LatinModernMono12:regular:9 some_file.txt
where :
print_cmd ::= some printing... (1 Reply)
Hi 2 all,
i have had AIX 7.2
:/# /usr/IBMAHS/bin/apachectl -v
Server version: Apache/2.4.12 (Unix)
Server built: May 25 2015 04:58:27
:/#:/# /usr/IBMAHS/bin/apachectl -M
Loaded Modules:
core_module (static)
so_module (static)
http_module (static)
mpm_worker_module (static)
... (3 Replies)
Discussion started by: penchev
3 Replies
LEARN ABOUT DEBIAN
mason::manual::intro
Mason::Manual::Intro(3pm) User Contributed Perl Documentation Mason::Manual::Intro(3pm)NAME
Mason::Manual::Intro - Getting started with Mason
DESCRIPTION
A few quick examples to get your feet wet with Mason. See Mason::Manual::Setup for how to use Mason to generate web sites.
EXAMPLE 1
Hello world (from command-line)
After installing Mason, you should have a "mason" command in your installation path (e.g. "/usr/local/bin"). Try this:
% mason
Hello! The local time is <% scalar(localtime) %>.
^D
(where '^D' means ctrl-D or EOF). You should see something like
Hello! The local time is Wed Mar 2 17:11:54 2011.
The "mason" command reads in a Mason component (template), runs it, and prints the result to standard output. Notice that the tag
<% scalar(localtime) %>
was replaced with the value of its expression. This is called a substitution tag and is a central piece of Mason syntax.
EXAMPLE 2
Email generator (from script)
The command line is good for trying quick things, but eventually you're going to want to put your Mason components in files.
In a test directory, create a directory "comps" and create a file "email.mc" with the following:
<%class>
has 'amount';
has 'name';
</%class>
Dear <% $.name %>,
We are pleased to inform you that you have won $<% sprintf("%.2f", $.amount) %>!
Sincerely,
The Lottery Commission
<%init>
die "amount must be a positive value!" unless $.amount > 0;
</%init>
In addition to the substitution tag we've seen before, we declare two attributes, "amount" and "name", to be passed into the component; and
we declare a piece of initialization code to validate the amount.
In the same test directory, create a script "test.pl" with the following:
1 #!/usr/local/bin/perl
2 use Mason;
3 my $interp = Mason->new(comp_root => 'comps', data_dir => 'data');
4 print $interp->run('/email', name => 'Joe', amount => '1500')->output;
Line 3 creates a Mason interpreter, the main Mason object. It specifies two parameters: a component root, indicating the directory
hierarchy where your components will live; and a data directory, which Mason will use for internal purposes such as class generation and
caching.
Line 4 runs the template - notice that the ".mc" extension is added automatically - passing values for the "name" and "amount" attributes.
Run "test.pl", and you should see
Dear Joe,
We are pleased to inform you that you have won $1500.00!
Sincerely,
The Lottery Commission
SEE ALSO
Mason::Manual::Tutorial, Mason::Manual
AUTHOR
Jonathan Swartz <swartz@pobox.com>
COPYRIGHT AND LICENSE
This software is copyright (c) 2011 by Jonathan Swartz.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.
perl v5.14.2 2012-05-02 Mason::Manual::Intro(3pm)