Search results
Results from the WOW.Com Content Network
Originally, filehandles could only be created with package variables, using the ALL_CAPS convention to distinguish it from other variables. Perl 5.6 and newer also accept a scalar variable, which will be set (autovivified) to a reference to an anonymous filehandle, in place of a named filehandle.
#!/usr/bin/perl # Loads the module and imports any functions into our namespace # (defaults to "main") exported by the module. Hello::World exports # hello() by default. Exports can usually be controlled by the caller. use Hello::World; print hello (); # prints "Hello, world!\n" print hello ("Milky Way"); # prints "Hello, Milky Way!\n"
Perl provides three loop control keywords that all accept an optional loop label as an argument. If no label is specified, the keywords act on the innermost loop. Within nested loops, the use of labels enables control to move from an inner loop to an outer one, or out of the outer loop altogether.
Perl Programming Documentation, also called perldoc, is the name of the user manual for the Perl 5 programming language. It is available in several different formats, including online in HTML and PDF. The documentation is bundled with Perl in its own format, known as Plain Old Documentation (pod).
#!usr/bin/perl – called the "shebang line", after the hash symbol (#) and ! (bang) at the beginning of the line. It is also known as the interpreter directive. # – the number sign, also called the hash symbol. In Perl, the # indicates the start of a comment. It instructs perl to ignore the rest of the line and not execute it as script code.
In Perl, foreach (which is equivalent to the shorter for) can be used to traverse elements of a list. The expression which denotes the collection to loop over is evaluated in list-context and each item of the resulting list is, in turn, aliased to the loop variable. List literal example:
The Perl virtual machine is a stack-based process virtual machine implemented as an opcodes interpreter which runs previously compiled programs written in the Perl language. The opcodes interpreter is a part of the Perl interpreter, which also contains a compiler (lexer, parser and optimizer) in one executable file, commonly /usr/bin/perl on various Unix-like systems or perl.exe on Microsoft ...
The read–eval–print loop involves the programmer more frequently than the classic edit–compile–run–debug cycle. Because the print function outputs in the same textual format that the read function uses for input, most results are printed in a form that could be copied and pasted back into the REPL. However, it is sometimes necessary ...