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firekiller15 asked on

What is this symbol mean in perl

PERL
What is this symbol mean in perl



use Net :: FTP // what is use and :: mean

my $TRUE=1     // what is my mean

if (not -e $writetofile) //what -e mean here

foreach $morse1 (@food) {
  eval {   //What is eval mean

if ($@)  //What is $@ mean?

$ftp->login() // what is "->" mean  


chomp;         //what this mean
s/#.*//;       //what this mean
s/^\s+//;      //what this mean
s/\s+$//;      /what this mean    
next unless length;   //what this mean
my ($var,$value)=split(/\s*=\s*/,$_,2); //what this mean
$Configuration{$var}=$value; //is this associative array??

$stmtcompnumber=$dbh->prepare($a); //what is perpare for
$stmtcompnumber->bind_param(1,$$b); //what is bind_param and parameter 1 for
 

$a .= "\"$arow[0]\"|";  //what is this use for?
Perl

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Last Comment
ozo

8/22/2022 - Mon
ASKER
firekiller15

can i know why
#VARIABLES
my $ftphostname = ""; need to declare this
ASKER
firekiller15

as a empty string
ASKER
firekiller15

my ($universeid)=@_;// what is @_ mean
Your help has saved me hundreds of hours of internet surfing.
fblack61
ozo

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

               If EXPR is a bareword, the require assumes a ".pm" extension
               and replaces "::" with "/" in the filename for you, to make it
               easy to load standard modules.  This form of loading of modules
               does not risk altering your namespace.



       The Arrow Operator

       ""->"" is an infix dereference operator, just as it is in C and C++.
       If the right side is either a "[...]", "{...}", or a "(...)" subscript,
       then the left side must be either a hard or symbolic reference to an
       array, a hash, or a subroutine respectively.  (Or technically speaking,
       a location capable of holding a hard reference, if it's an array or
       hash reference being used for assignment.)  See perlreftut and perlref.

       Otherwise, the right side is a method name or a simple scalar variable
       containing either the method name or a subroutine reference, and the
       left side must be either an object (a blessed reference) or a class
       name (that is, a package name).  See perlobj.



       @ARG
       @_      Within a subroutine the array @_ contains the parameters passed
               to that subroutine.  See perlsub.
ASKER CERTIFIED SOLUTION
Adam314

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ozo

Sorry, I didn't notice the rest of the questions
 perldoc perldata
       Scalar values are always named with '$', even when referring to a
       scalar that is part of an array or a hash.  The '$' symbol works
       semantically like the English word "the" in that it indicates a single
       value is expected.

           $days               # the simple scalar value "days"
           $days[28]           # the 29th element of array @days
           $days{'Feb'}        # the 'Feb' value from hash %days
           $#days              # the last index of array @days


perldoc perlop
 

       Binary "." concatenates two strings.


       Assignment Operators

       "=" is the ordinary assignment operator.

       Assignment operators work as in C.  That is,

           $a += 2;

       is equivalent to

           $a = $a + 2;

       although without duplicating any side effects that dereferencing the
       lvalue might trigger, such as from tie().  Other assignment operators
       work similarly.  The following are recognized:

           **=    +=    *=    &=    <<=    &&=
                  -=    /=    |=    >>=    ||=
                  .=    %=    ^=           //=
                        x=


perldoc DBI