Start Coding

Subjects

JAVASCRIPTHTMLCSSPYTHONSQLJAVACPPCSHARPPHPTYPESCRIPTCRUBYGOSWIFTKOTLINRUSTRBASHSCALAOBJECTIVE-CDARTPERLLUAMATLABXMLJSONMARKDOWNASSEMBLYLATEXYAMLSOLIDITYBLOCKCHAIN

Topics

Perl Basics

Introduction to PerlInstalling PerlPerl SyntaxPerl VariablesPerl Data TypesPerl OperatorsPerl CommentsPerl Print StatementsPerl Input/OutputPerl Command Line Arguments

Control Structures

Perl If-Else StatementsPerl Unless StatementPerl Switch StatementPerl For LoopsPerl While LoopsPerl Do-While LoopsPerl Loop Control StatementsPerl Ternary Operator

Perl Subroutines

Defining Perl SubroutinesPerl Subroutine ArgumentsPerl Return ValuesPerl Anonymous SubroutinesPerl Recursive SubroutinesPerl Subroutine References

Perl Data Structures

Perl ArraysPerl HashesPerl Multidimensional ArraysPerl Array and Hash SlicesPerl ReferencesPerl Complex Data Structures

Perl String Manipulation

Perl String BasicsPerl String FunctionsPerl Regular ExpressionsPerl Pattern MatchingPerl String FormattingPerl Here Documents

Perl File Handling

Perl File Open and ClosePerl File ReadingPerl File WritingPerl File AppendingPerl Directory HandlingPerl File Test Operators

Perl Modules

Using Perl ModulesCreating Perl ModulesPerl Standard ModulesPerl CPANPerl Module VersioningPerl Object-Oriented Modules

Perl Object-Oriented Programming

Perl OOP BasicsPerl Classes and ObjectsPerl InheritancePerl EncapsulationPerl PolymorphismPerl Method Overriding

Perl Exception Handling

Perl Die and WarnPerl Eval FunctionPerl Try-Catch BlocksPerl Custom ExceptionsPerl Error Handling Best Practices

Perl Database Interaction

Perl DBI ModulePerl Database ConnectionPerl SQL QueriesPerl Prepared StatementsPerl Database Transactions

Perl Web Development

Perl CGI ProgrammingPerl and HTML FormsPerl Session HandlingPerl CookiesPerl Web Frameworks (e.g., Mojolicious)

Perl Network Programming

Perl Socket ProgrammingPerl Client-Server CommunicationPerl and HTTPPerl and FTPPerl and Email Handling

Perl System Administration

Perl Process ManagementPerl File System OperationsPerl System Information RetrievalPerl and Shell CommandsPerl Log File Analysis

Perl Testing and Debugging

Perl Debugging TechniquesPerl Unit TestingPerl Test::More ModulePerl Code CoveragePerl Profiling

Advanced Perl Concepts

Perl References and PointersPerl TypeglobsPerl Symbol TablesPerl Tie InterfacePerl ClosuresPerl BenchmarkingPerl Internals

Perl String Formatting

String formatting in Perl allows developers to create structured and formatted output. It's an essential skill for presenting data in a readable and organized manner.

Basic String Formatting

Perl offers several methods for string formatting. The most common are sprintf and printf functions.

sprintf Function

The sprintf function returns a formatted string without printing it. It's useful when you need to store the formatted string for later use.


my $formatted = sprintf("Name: %s, Age: %d", "John", 30);
print $formatted;  # Output: Name: John, Age: 30

printf Function

printf is similar to sprintf, but it prints the formatted string directly.


printf("Balance: $%.2f\n", 1234.5678);  # Output: Balance: $1234.57

Format Specifiers

Format specifiers are placeholders used in formatting strings. They start with a percent sign (%) followed by a character that indicates the data type.

  • %s - String
  • %d - Integer
  • %f - Float
  • %x - Hexadecimal
  • %o - Octal

Advanced Formatting

Perl's string formatting capabilities extend beyond basic placeholders. You can specify width, precision, and alignment.


printf("|%-10s|%10s|\n", "Left", "Right");
# Output: |Left      |     Right|

printf("Pi: %.*f\n", 3, 3.14159265);
# Output: Pi: 3.142

The format Function

For more complex formatting needs, Perl provides the format function. It's particularly useful for creating report-like output.


format STDOUT =
Name: @<<<<<<<<<<<<<<  Age: @>>
      $name,                $age
.

$name = "Alice";
$age = 25;
write;  # Outputs the formatted text

Best Practices

  • Use sprintf when you need to store the formatted string.
  • Prefer printf for direct output to avoid unnecessary variable creation.
  • Be cautious with user input to prevent format string vulnerabilities.
  • Consider using Perl Here Documents for multi-line formatted strings.

Mastering string formatting in Perl enhances your ability to create clean, readable output. It's a crucial skill that complements other Perl String Functions and is often used in conjunction with Perl Regular Expressions for powerful text processing capabilities.