-
-
system "mkdir -p $temp/engl_2/wf";
}
if ( ! -s "$temp/backup_basedir" ) {
system "mkdir -p $temp/backup_basedir";
}
${pack_2}= -M "${temp}/engl_2/wf/${wf_package_name}.data";
${new_pack}= -M "${pack}/package.data";
This is a sample script of perl language.
What is the use of "-s" and "-M" in the above script? ">#create directory if not thereif ( ! -s "$temp/engl_2/wf" ) { system "mkdir -p $temp/engl_2/wf";}if ( ! -s "$temp/backup_basedir" ) { system "mkdir -p $temp/backup_basedir";}${pack_2}= -M "${temp}/engl_2/wf/${wf_package_name}.data";${new_pack}= -M "${pack}/package.data";This is a sample script of perl language.What is the use of "-s" and "-M" in the above script?
mpathak
- Dec 5th, 2007
Use File::Path;if(! -d "$DIR"){ mkpath("$DIR") || die("Could not create directory");}
vinod
- Sep 9th, 2007
-s ==> Is filename a non-empty file?-M ==> How long since filename modified?
-
When would you not use Perl for a project?
prabhasgupte
- Feb 12th, 2008
Perl programs are generally used for: - text processsing - text mining - test automation - simple network programming (simple sockets, just fetching webpage and parsing ...
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What are advantages of Perl over C, and of C over Perl ?
sapam
- Apr 1st, 2008
Advantages of PERL over C1) Perl runs on all platforms and is far more portable than C. 2) Perl and a huge collection of Perl Modules are free software (either GNU General Public License or Artist...
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What is eval in perl?
sapam
- Apr 1st, 2008
The eval function provides a very simple way of checking certain events without affecting the overall execution of your script. In essence, the eval function just initiates a new instance of the Perl ...
acraul7
- Mar 5th, 2008
Eval is also used for evaluating expressions.For eg:$a = 1;$b = 3;$c = '$a*$b';print(eval "$c"); // This prints 3
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Symbolic Reference in PERL
What is the Use of Symbolic Reference in PERL?
imavasu
- May 3rd, 2008
> $name = "bam";> $$name = 1; # Sets $bam> ${$name} = 2; # Sets $bam> ${$name x 2} = 3; # Sets $bambam> $name->[0] = 4; # Sets $bam[0]symbolic reference means using a string as a reference.
-
What is the use of "STDERR()"?
imavasu
- May 13th, 2008
Perl is like this but (being Perl) goes a step further. The following file handles are open by default:STDIN - Standard Input, for user control input, typically the keyboardSTDOUT - Standard Output,fo...
Fahad
- Sep 29th, 2006
Hi, this is what i found.STDERRThe special filehandle for standard error in any package.
-
What are regular expressions?
prabhath_01
- May 31st, 2008
Regular Expresiions is the heart of Perl language.Using this we can search and raplace with partcular pattern in a given text.We can read a file and replace all occurances of some word or pattern with...
Sunil Kartikey
- Sep 18th, 2006
A code line that defines a pattern for a search to match
-
"perl regular expressions are greedy" what does this mean?
prabhath_01
- May 31st, 2008
We have wild card characters like '*' and '+' in perl, which are greedy by natureEg:., Let's discuss with an example In the following string you want to match 'Perl is aw...
-
What's is the use of 'require' and what does this mean?
nitashaa
- Jul 15th, 2008
require function is used to load a seperate perl script or module in run time.If the file to be loaded is not in the directories listed in @INC array then full path of the perl file is to be passed in...
Swanand
- Mar 27th, 2007
'require' is like a preprocessor directive in C/C++ which imports the external file .You can use the subroutines inside the current source code which are defined in the external file.require 'coreDBlib.pl'?=>> #include
-
What does the word '&myvariable' mean?what does the symbol '&' means? What's purpose of it?
nitashaa
- Jul 15th, 2008
&myvariable;It indicates 'myvariable' is a subroutine which is being called in the above statement .Its mandatory to use & keyword before subroutine name only when userdefined subrouti...
maruthr
- Apr 16th, 2008
There are three different formats to be used for calling the subroutines/methods,"hello" is the subroutine name, say1) &hello;Subroutine definition can be made anywhere in the fil...
-
What is a subroutine?
nitashaa
- Jul 15th, 2008
One major difference between subroutine and function-A function definition must have a return statement whereas a subroutine always return value of last expression evaluated in case there is no return statement.
-
What are the characteristics of project that is well suited to PERL
ashwini chavan
- Jul 22nd, 2008
When to use Perl1. For large text processing2. When application does lot of data manipulation3. When you need fast development4. For database loading operations5. When shell scrits grow to become libraries
bibhu prasanna behera
- Jun 25th, 2007
Actually it is used in automation testing....as a tester i am using per script for automation testing like running the tools etc.
-
What is hash in perl?
ashwini chavan
- Jul 22nd, 2008
Hash is an associative array where data is stored in "key"->"value" pairs.Eg : fruits is a hash having their names and price%fruits = ("Apple", "60", "Banana", "20", "Peers", "40");
wow_suraj
- May 2nd, 2008
Hash is also known as 'Associative array' sometimes. It basicaly contains of two parts first is key and value. It is very much like a name given for a value.Ex. A student with his/her roll number can ...
-
What does this mean : '$_' ?
ashwini chavan
- Jul 22nd, 2008
The most commonly used global scalar variable is the $_ variable. Many Perl functionsand operators modify the contents of $_ if you do not explicitly specify the scalarvariable on which they are to op...
prabhath_01
- May 31st, 2008
It is called as default variable in Perl.It hold the current value in any block ie., 'for' or 'while'. Eg.,******************************************print "n", $_ for (1..10)...
-
What is the difference between object oriented and structured oriented progrmming?
vinkumardpi
- Nov 6th, 2008
* Object Oriented means programme will be their in terms of Class and Object relationship will be their.* Structured Oriented Means programme will be their in terms of multiple Functions.
-
What does 'qw(..)' mean? What's the use of it?when do we use it?
wow_suraj
- Jun 8th, 2009
qw stands for 'Quote word'. It usually used to create array. Ex. @arr = qw/one two three/; ...
gnana
- Oct 31st, 2006
The quoting opeator for lists is qw.advantage of qw is you need not quote the strings in additional way as qw already does quoting.
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Why do you program in PERL
gireeshkumar.kg
- Jun 29th, 2009
* PERL is programmer friendly. It is easy to code and can do it in less number of lines. It does all the nice things with minimum fuzz.* Text manipulation is unmatched. * It has built-in regex.* Has the support of world's largest archive of modules(CPAN)
ashwini chavan
- Jul 22nd, 2008
It is having the features of scripting (Shell) as well as programming (like C). Using PERL you can easily do the system administration works where comparitively difficult with Shell script.
-
Explain the difference between "my" and "local" variable scope declarations. ?
Both of them are used to declare local variables.The variables declared with "my" can live only within the block it was defined and cannot get its visibility inherited functions called within that block, but one defined with "local" can live within the block and have its visibility in the functions called within that block.
gireeshkumar.kg
- Jun 29th, 2009
1) MyMy creates a new variable and gives a lexical scope for that variable.The variable? is not visible outside the block in which it is defined.2) LocalLocal saves the value of a global variable.It ...
vamshi_maham
- Oct 9th, 2007
Perl supports three scoping declarations that enable to create private variables (using my) , selectively global variable (using our) and temporary copies of selected global variables (using local) .....
-
What is difference between "Use" and "require". In which case should "Use" be used and not "Require"?
gireeshkumar.kg
- Jun 29th, 2009
1)Usei) use for loading the modules( Should not give the .pm extension)ii) The loaded module is verified at the compile time.2) Requirei) Use for loading the modules and perl programs( .pm extension i...
prabhasgupte
- Feb 12th, 2008
There is one more basic difference between 'use' and 'require'.When you 'use' the control is passed to that file at runtime.Whereas, when you 'require' the code from th...
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