Single file method

perl -pi -e "s/\r//" filename.txt

Multiple File Method

find . -type f -exec perl -pi -e "s/\r//" {} \;

rajeshkumar replied the topic: Re:Remove Control ^M from files
I used to do in shell using following command

> 1,$s/^M//g

Correct me if I am wrong
Regards,
Rajesh Kumar
Twitt me @ twitter.com/RajeshKumarIn

tpatil replied the topic: Re:Remove Control ^M from files

Yes, this is also correct command if you want to remove ^M from single file in VI edit mode.

The post Remove Control ^M from files appeared first on scmGalaxy.

There is a file called test.txt what are all the different ways

BEGIN:
test 1
test 2 %%%%%%%%%% TEST TEST TEST
test 3
END:

need to grab all contents in between BEGIN and END:
Regards,
Rajesh Kumar
Twitt me @ twitter.com/RajeshKumarIn

rajeshkumar replied the topic: Re:i need to a perl script

Solution could be …..

#!/usr/bin/perl -w
$file=open(f, "test.txt");
$str="";
while() {$str.=$_;}
close(f);
$str =~ s/BEGIN:(.*)END:/$1/egs;
print $str

Regards,
Rajesh Kumar
Twitt me @ twitter.com/RajeshKumarIn

venu.madhav48@gmail.com replied the topic: Re:i need to a perl script

Please answer the below questions

1.What standard Perl modules have you made use of, and why did you use them instead of the equivalent built-in functions?

2.Write a statement that checks to make sure there are at least two command line arguments and exits with an error if not.

3.How do you find the number of elements in an array?

4.When an array is defined, PERL automatically numbers each element in the array
beginning with zero

venu.madhav48@gmail.com replied the topic: Re:i need to a perl script
Dear Rajesh,

Can u please help in answering the above questions

rajeshkumar replied the topic: Re:i need to a perl script

Hi Venu,

i will post this solution today evening…
Regards,
Rajesh Kumar
Twitt me @ twitter.com/RajeshKumarIn

venu.madhav48@gmail.com replied the topic: Re:i need to a perl script
Waiting for your post….

The post I need to a perl script appeared first on scmGalaxy.

There is a subtle difference.

In the example below, $::a refers to $a in the ‘global’ namespace.
‘local’ temporarily changes the value of the variable, but only within the scope it exists in.
$a = 3.14159;
{
local $a = 3;
print “In block, \$a = $a\n”;
print “In block, \$::a = $::a\n”;
}

print “Outside block, \$a = $a\n”;
print “Outside block, \$::a = $::a\n”;

# This outputs In block,

# This outputs
In block, $a = 3
In block, $::a = 3
Outside block, $a = 3.14159
Outside block, $::a = 3.14159

‘my’ has no effect on the global $a, even inside the block.

$a = 3.14159;
{
my $a = 3;
print “In block, \$a = $a\n”;
print “In block, \$::a = $::a\n”;
}
print “Outside block, \$a = $a\n”;
print “Outside block, \$::a = $::a\n”;

# This outputs
In block, $a = 3
In block, $::a = 3.14159
Outside block, $a = 3.14159
Outside block, $::a = 3.14159

Regards,
Rajesh Kumar
Twitt me @ twitter.com/RajeshKumarIn

scmuser replied the topic: Re: The difference between my and local

With more explanation…

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.

The post The difference between my and local appeared first on scmGalaxy.

Could you please tell me meaning of rigging in perl?

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What is the difference between having a parenthesis after module name and without parenthsis after module name?? i.e

Package::Module();

Package::Module;

The post Parenthesis After Module Name And Without Parenths appeared first on scmGalaxy.

I have one question regarding to eval function. I know eval function is use for error checking but I am not able to understand below line.

eval \'exec perl -S $0 ${1+\"$@\"}\' if 0; $0

for script name $@ set if error occur

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Write a Perl script to find a particular word in a paragraph???

The post Find a particular word in a paragraph appeared first on scmGalaxy.

How to create a flat file database as shown below

s.no name age city phone
0 hema 22 Calcutta 4312542
1 hema 21 Bangalore 2344345
2 ganesh 25 delhi 2445454
3 kartik 45 pune 4312121
4 santosh 25 Hyderabad 2254231
5 kumar 25 mysore 2344567
6 gita 34 mangalore 6532123
7 gita 32 pune 2213456

Q1.print the details of the person who r from bangalore

Q2.Replace the city name managlore to pune

Q3.prints no of person having name gita and hema

Q4.print how many are of age 25

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Write a perl script to find whether a given line of text is starting and ending with same word or not ???

The post Find whether a given line of text is starting and appeared first on scmGalaxy.

Hi,

Whats difference between “use” and “require” in perl?

rajeshkumar replied the topic: Re: use Vs require in perl

use is done at ‘compile-time’ and require is done at ‘run-time’ (ie can conditionally load modules)

Regards,
Rajesh Kumar
Twitt me @ twitter.com/RajeshKumarIn

rajeshkumar replied the topic: Re: use Vs require in perl
More…

use is a pre-built in function in perl to Imports some semantics into the current package from the named module, generally by aliasing certain subroutine or variable names into your package such as..

* use Module VERSION LIST

* use Module VERSION
* use Module LIST
* use Module
* use VERSION

More info.. perldoc.perl.org/functions/use.html

Regards,
Rajesh Kumar
Twitt me @ twitter.com/RajeshKumarIn

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How to Spit out warnings on uninitialized variables in Perl?

rajeshkumar replied the topic: Re: Spit out warnings on uninitialized variables Perl

#!/usr/local/bin/perl -w

This will help you (really, it will force you) to write better, cleaner code. Adding the -w switch to the perl interpreter will cause it to spit out warnings on uninitialized variables – potential bugs.

Regards,
Rajesh Kumar
Twitt me @ twitter.com/RajeshKumarIn

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Perl modules may be installed using the CPAN module or from source.
CPAN method

perl -MCPAN -e shell (to get an interactive CPAN shell)
perl -MCPAN -e ‘install Time::JulianDay’ (if you know the name of the module, you can install it directly without interacting with the CPAN shell)

Within the CPAN shell:
i /expression/ will search for a Perl module containing expression, and
install module will install the module.

Example:
perl -MCPAN -e shell
i /JulianDay/
install Time::JulianDay

Note: if you are behind a firewall, you may wish to use passive FTP with Perl’s Net::FTP module. Set the environment variable FTP_PASSIVE 1 (or any non-zero value) to use passive FTP when downloading Perl modules through CPAN.

Manual installation

To manually install a Perl module:

1. Download the Perl module from CPAN or other site.
2. Extract the tarball.
3. Run perl Makefile.PL
4. Run make
5. Run make test
6. Run make install

Note: you should use the same compiler to build Perl modules that you used to build Perl. For example, if you are building Perl modules with gcc and are using a version of Perl that was supplied with your distribution (ex. Solaris 8 includes Perl 5.005_03), you may run into errors.

Checking for existence of a Perl module
An easy way to check for the existence of a Perl module on your system (technically, in Perl’s @INC array, a list of directories Perl searches when attempting to load modules) is to run perl -e ‘use module;’

Example:

perl -e ‘use HTML::Parser;’

Regards,
Rajesh Kumar
Twitt me @ twitter.com/RajeshKumarIn

The post Installing Perl modules appeared first on scmGalaxy.

I am getting following error while running following command…any help

> perl -MCPAN -e "install DBD::mysql";

Error

D:\wamp\bin\mysql\MYSQL5~1.36\bin\MYSQLA~1.EXE: connect to server at 'localhost'
failed
error: 'Access denied for user 'ODBC'@'localhost' (using password: NO)'
Problem running D:\wamp\bin\mysql\MYSQL5~1.36\bin\MYSQLA~1.EXE - aborting ...

Regards,
Rajesh Kumar
Twitt me @ twitter.com/RajeshKumarIn

The post Access denied for user ‘ODBC’@’localhost appeared first on scmGalaxy.

I am getting following issues while running following command in Windows Machine…

perl -MCPAN -e "install DBD::mysql"

Error

Regards,
Rajesh Kumar
Twitt me @ twitter.com/RajeshKumarIn

The post Perl -MCPAN -e “install DBD::mysql” appeared first on scmGalaxy.

Hi,

why do we use following syntax in perl program. can you please explain it?

use DBI;

rajeshkumar replied the topic: Re: Use of use DBI;

Perl’s coolest modules is the Perl database interface (DBI). This module offers a unified interface to different databases, providing a series of generic functions that are internally translated into native function calls. This makes it extremely easy to take advantage of a database and create dynamic Web pages using Perl.

Download and install

To begin, download and install the Perl DBI module and the MySQL DBD driver by running the following commands at your Perl prompt:

perl> perl -MCPAN -e "install DBI"
perl> perl -MCPAN -e "install DBD::mysql"

PERL – DBI Query

Queries must be prepared and then executed. Two lines of code are required for this, first the prepare() function and then the execute() function.

PERL – DBI Prepare()

Inside the prepare() function lies the actual SQL query. Essentially the prepare function acts precisely like the console of an SQL platform. If you’ve been following along, all we need to do is define a variable with a(n) SQL statement. Then create a query handle and run our $connect statement along with the prepare function as outlined below.

The only main difference is that we have to use PERL’s escaping characters and we probably have to use them more often.

PERL – DBI Execute
Once the query has been prepared, we must execute the command with the execute function. This is accomplished in one final line appended to the code above.

PERL – DBI Select Queries
Select queries fetch results and then return those results in the form of an array. Accessing the results of the array requires first that we bind the columns to variable names. Then we just need to set up a loop to loop through each row and print back the results to our browser.

#!/usr/bin/perl

# LOOP THROUGH RESULTS
while($query_handle->fetch()) {
print "$id, $product, $quantity
";
}

Regards,
Rajesh Kumar
Twitt me @ twitter.com/RajeshKumarIn

rajeshkumar replied the topic: Re: Use of use DBI;

One more example for connecting database using perl

You can connect to MySQL database from a Perl script using the Perl DBI module. DBI stands for “Database Interface” and is a database layer, with simple interface for SQL queries. Here is a Perl script connecting to MySQL database and printing FirstName and LastName columns from a table called Users:
#!/usr/local/bin/perl

use DBI;

print “Content-type:text/html\n\n”;

$dbh = DBI->connect(“dbi:mysql:database=; host=localhost; user=; password=”)
or die “Connecting from PHP to MySQL database failed: $DBI::errstr”;

$sSQL = “SELECT FirstName, LastName FROM Users”;
$st = $dbh->prepare($sSQL)
or die “Preparing MySQL query failed: $DBI::errstr
“;

$st->execute()
or die “The execution of the MySQL query failed: $DBI::errstr”;

while ($row = $st->fetchrow_hashref())
{
print ” $row->{FirstName} $row->{LastName}
“;
}

$dbh ->disconnect();

Regards,
Rajesh Kumar
Twitt me @ twitter.com/RajeshKumarIn

rajeshkumar replied the topic: Re: Use of use DBI;

One more example…

#!/usr/bin/perl
use DBI;

$dbh->disconnect;

where DBNAME, DBUSERNAME, and DBPASSWORD are your database name, database username and database password, and where DBSERVER is your database server.

Regards,
Rajesh Kumar
Twitt me @ twitter.com/RajeshKumarIn

The post Use of use DBI; appeared first on scmGalaxy.

#!/usr/bin/perl
use DBI;

$database = “DBNAME”;
$hostname = “DBSERVER”;
$port = “3306”;
$username = “DBUSERNAME”;
$password = ‘DBPASSWORD’;

$dsn = “DBI:mysql:database=$database;host=$hostname;port=$port”;

$dbh = DBI->connect($dsn, $username, $password) or die(“Could not connect!”);

$sql = “SELECT * FROM mytable”;

$sth = $dbh->prepare($sql);
$sth->execute;

while(($column1, $column2) = $sth->fetchrow_array)
{
print “C1 = $column1, C2 = $column2n”;
}

$dbh->disconnect;

where DBNAME, DBUSERNAME, and DBPASSWORD are your database name, database username and database password, and where DBSERVER is your database server.

Regards,
Rajesh Kumar
Twitt me @ twitter.com/RajeshKumarIn

The post Connect to my MySQL database using Perl? appeared first on scmGalaxy.

Hi,

Why you should ‘use strict’? what is the significant of “strict” in out module?

rajeshkumar replied the topic: Re: Why we use ‘use strict’ in perl

Whenever your program gets over a few lines long, definitely when you can’t view the whole program on one page, or sometimes when you just can’t figure out what else could be wrong.

To help you catch typos so you can quickly get on to finding more significant problems (and so we don’t have to catch the typos for you either), among other reasons.
Its difficult to spot ‘$recieve_date’ when on the previous page you’ve been calling it ‘$receive_date’. Also, to give your variables as small a scope as possible so that you don’t have to worry about what they’re doing to other parts of your program (although that’s the function of my, it forces you to use my which when properly used helps achieve this goal).

Put this line at the top of your script (after the shebang, e.g., ‘#!/usr/bin/perl’ line):

use strict;
# Change this:
$string = "hello world";
@array = qw(ABC DEF);
%hash = (A=>1, B=>2);

# To this (the '\' is distributed over a list of values):
$sth->bind_columns(\my ($field1, $field2));
while ($sth->fetch) {
print "F1: $field1 F2: $field2\n";
}

Regards,
Rajesh Kumar
Twitt me @ twitter.com/RajeshKumarIn

rajeshkumar replied the topic: Re: Why we use ‘use strict’ in perl

Some More Helpful info…

By default Perl allows you to use variables without declaring them. This may be convenient for short scripts and one-liners.But in a longer unit of code such as a module it is wise to declare your variables both to catch typos and to constrain their accessibility appropriately from outside the module. The strict pragmaforces you to declare your variables.

If no import list is supplied, all possible restrictions are assumed. (This is the safest mode to operate in, but is sometimes too strict for casual programming.) Currently, there are three possible things to be strict about: “subs”, “vars”, and “refs”.

strict refs
This generates a runtime error if you use symbolic references
1. use strict ‘refs’;
2. $ref = \$foo;
3. print $$ref; # ok
4. $ref = “foo”;
5. print $$ref; # runtime error; normally ok
6. $file = “STDOUT”;
7. print $file “Hi!”; # error; note: no comma after $file

strict vars

This generates a compile-time error if you access a variable that wasn’t declared via our or use vars , localized via my(), or wasn’t fully qualified. Because this is to avoid variable suicide problems and subtle dynamic scoping issues, a merely local() variable isn’t good enough.
1. use strict ‘vars’;
2. $X::foo = 1; # ok, fully qualified
3. my $foo = 10; # ok, my() var
4. local $foo = 9; # blows up
5.
6. package Cinna;
7. our $bar; # Declares $bar in current package
8. $bar = ‘HgS’; # ok, global declared via pragma

strict subs
This disables the poetry optimization, generating a compile-time error if you try to use a bareword identifier that’s not a subroutine, unless it is a simple identifier (no colons) and that it appears in curly braces or on the left hand side of the => symbol
1. use strict ‘subs’;
2. $SIG{PIPE} = Plumber; # blows up
3. $SIG{PIPE} = “Plumber”; # just fine: quoted string is always ok
4. $SIG{PIPE} = \&Plumber; # preferred form

Regards,
Rajesh Kumar
Twitt me @ twitter.com/RajeshKumarIn

The post Why we use ‘use strict’ in perl appeared first on scmGalaxy.

Why do you program in Perl? What are the advantages of Perl ovber python and other languages?

The post Why do you program in Perl? appeared first on scmGalaxy.

What are the Difference between exec and system in perl? please explain….

rajeshkumar replied the topic: Re: Difference between exec and system in perl?

exec function in perl

The exec function executes a system command and never returns; use system instead of exec if you want it to return. It fails and returns false only if the command does not exist and it is executed directly instead of via your system’s command shell

Since it’s a common mistake to use exec instead of system, Perl warns you if there is a following statement that isn’t die, warn, or exit (if -w is set–but you always do that, right?). If you really want to follow an exec with some other statement, you can use one of these styles to avoid the warning:
exec (‘foo’) or print STDERR “couldn’t exec foo: $!”;
{ exec (‘foo’) }; print STDERR “couldn’t exec foo: $!”;

Example:
$shell = ‘/bin/csh’;
exec $shell ‘-sh’; # pretend it’s a login shell

or
exec {‘/bin/csh’} ‘-sh’; # pretend it’s a login shell

More..

Executes a system command (directly, not within a shell) and never returns to the calling script, except if the command specified does not exist and has been called directly, instead of indirectly through a shell. The operation works as follows:

* If there is only one scalar argument that contains no shell metacharacters, then the argument is converted into a list and the command is executed directly, without a shell.
* If there is only one scalar argument that contains shell metacharacters, then the argument is executed through the standard shell, usually /bin/sh on Unix.
* If LIST is more than one argument, or an array with more than one value, then the command is executed directly without the use of a shell.

Return Value: 0 only if the command specified cannot be executed

Example

Following are the usage…
exec ‘/bin/echo’, ‘Your arguments are: ‘, @ARGV;
exec “sort $outfile | uniq”;

Another example:
exec {‘/bin/csh’} ‘-sh’; # pretend it’s a login shell

System function in perl

Does exactly the same thing as exec LIST , except that a fork is done first, and the parent process waits for the child process to exit. Note that argument processing varies depending on the number of arguments. If there is more than one argument in LIST, or if LIST is an array with more than one value, starts the program given by the first element of the list with arguments given by the rest of the list.

Executes the command specified by PROGRAM, passing LIST as arguments to the command.The return value is the exit status of the program as returned by the wait function. To obtain the actual exit value, divide by 256.

Return Value : Exit status of program as returned by wait

Example

Try out following example:
#!/usr/bin/perl -w
system(“ls -F /var > /tmp/t.tmp”);

It will produce following result:

A file in /tmp direcory, check it out.

Regards,
Rajesh Kumar
Twitt me @ twitter.com/RajeshKumarIn

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Any sample program??

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