5. Perl

  • 5.1. Perl tutorial
    Perl is the abbreviation of Practical Extraction and Report Language and can be translated into “practical r...
    2023-10-20 00:50:12 UTC
  • 5.2. Perl introduction
    Perl, a feature-rich computer programming language, runs on more than 100 computer platforms and is suitable for a wid...
    2023-10-20 23:00:03 UTC
  • 5.3. Perl environment installation
    Before we can start learning the Perl language, we need to install the Perl execution environment. Perl can r...
    2023-10-20 23:00:03 UTC
  • 5.4. Perl basic syntax
    Perl borrows the features of C, sed, awk, shell scripts, and many other programming languages, and the syntax is somew...
    2023-10-20 23:00:04 UTC
  • 5.5. Perl data type
    Perl is a weakly typed language, so variables do not need to specify a type,and the Perl interpreter automatically sel...
    2023-10-20 23:00:04 UTC
  • 5.6. Perl variable
    A variable is data stored in memory, and creating a variable opens up a space in memory. The interpreter dete...
    2023-10-20 23:00:04 UTC
  • 5.7. Perl scalar
    Scalar is a simple data unit. Scalars can be an integer, floating point, character, string, paragraph, or a c...
    2023-12-11 00:55:03 UTC
  • 5.8. Perl array
    Perl array is a list variable that stores scalar values, and variables can be of different type...
    2023-10-20 23:00:04 UTC
  • 5.9. Perl hash
    The hash is key/value that’s right Gather. Perl hash variabl...
    2023-10-20 23:00:04 UTC
  • 5.10. Perl conditional statement
    Perl conditional statement is the result of the execution of one or more statements ...
    2023-10-20 23:00:03 UTC
  • 5.11. Perl IF statement
    Perl if statement consists of a Boolean expression followed by one or more statements. ...
    2023-10-23 23:00:03 UTC
  • 5.12. Perl IF…ELSE statement
    One if statement can be followed by an optional else statement ...
    2023-10-20 23:00:03 UTC
  • 5.13. Perl IF…ELSIF statement
    One if statement can be followed by an optional elsif statement, a...
    2023-10-20 23:00:04 UTC
  • 5.14. Perl UNLESS statement
    One unless statement consists of a Boolean expression followed by oneor more statements. ...
    2023-10-20 23:00:03 UTC
  • 5.15. Perl UNLESS…ELSE statement
    One unless statement can be followed by an optional else statement...
    2023-10-23 23:00:04 UTC
  • 5.16. Perl UNLESS…ELSIF statement
    One unless statement can be followed by an optional elsif statemen...
    2023-10-20 23:00:04 UTC
  • 5.17. Perl switch statement
    One switch statement allows you to test when a variable is equal to multiple values. Each va...
    2023-10-20 23:00:04 UTC
  • 5.18. Perl cycle
    Sometimes, we may need to execute the same piece of code multiple times. In general, statements are executed sequentia...
    2023-10-20 23:00:04 UTC
  • 5.19. Perl while cycle
    while statement when a given condition is true the statement or group...
    2023-10-20 23:00:03 UTC
  • 5.20. Perl until cycle
    until statement when a given condition is false statement or group of...
    2025-10-25 12:21:08 UTC
  • 5.21. Perl for cycle
    Perl for loops are used to execute a sequence of statements multiple times, simplifying the ...
    2023-10-20 23:00:03 UTC
  • 5.22. Perl foreach cycle
    Perl foreach loop is used to iterate over the value of a list or collection variable. ...
    2023-10-20 23:00:03 UTC
  • 5.23. Perl do…while cycle
    Not like for and while loops, they test the loop conditions at the...
    2023-10-20 23:00:04 UTC
  • 5.24. Perl loop nesting
    Perl language allows the use of another loop within one loop, and here are a few examples to il...
    2023-10-20 23:00:03 UTC
  • 5.25. Perl next statement
    Perl next statement is used to stop execution from the next the st...
    2023-10-20 23:00:04 UTC
  • 5.26. Perl last statement
    Perl last statement is used to exit the loop statement block, thus ending the loop ...
    2023-10-20 23:00:04 UTC
  • 5.27. Perl continue statement
    Perl continue blocks are usually executed before the conditional statement is judged again. ...
    2023-10-20 23:00:03 UTC
  • 5.28. Perl redo statement
    Perl redo statement directly to the first line of the body of the loop to repeat the executi...
    2023-10-20 23:00:04 UTC
  • 5.29. Perl goto statement
    Perl has three forms of goto : got LABLE , ...
    2023-10-20 23:00:04 UTC
  • 5.30. Perl operator
    An operator is a symbol that tells the compiler to perform specific mathematical or logical operations, such as: ...
    2023-10-20 23:00:03 UTC
  • 5.31. Perl time date
    In this chapter, we introduce to you Perl treatment of time and date by language. T...
    2023-10-20 23:00:04 UTC
  • 5.32. Perl subroutine (function)
    Perl subroutines are user-defined functions. Perl subroutine is...
    2023-10-20 23:00:03 UTC
  • 5.33. Perl reference
    A reference is a pointer. Perl reference is a scalar type that can point to variables, array...
    2023-10-20 23:00:04 UTC
  • 5.34. Perl formatted output
    Perl is a very powerful text data processing language. Perl can...
    2023-10-20 23:00:03 UTC
  • 5.35. Perl file operation
    Perl use a variable called the file handle type to manipulate the file. A file handle ...
    2023-10-20 23:00:04 UTC
  • 5.36. Perl directory operation
    Some standard functions for operating directories are listed below: Opendir DIRHANDLE, EXPR # Open direc...
    2023-10-20 23:00:03 UTC
  • 5.37. Perl error handling
    In the process of running the program, you will always encounter all kinds of errors, such as opening a file that does...
    2023-10-20 23:00:04 UTC
  • 5.38. Perl special variable
    The Perl language defines some special variables, usually prefixed with $ , @ ...
    2023-10-23 23:00:03 UTC
  • 5.39. Perl regular expression
    Regular expression (regular expression) describes a pattern of string matching, which can be used to check whether a s...
    2023-10-20 23:00:04 UTC
  • 5.40. Perl sends mail
    If your program runs on Linux/Unix, you can use it in Perl sendmail tool to send mail. ...
    2023-10-23 23:00:03 UTC

Principles and Applications of WebGIS  37

IT Tools  337

Web Frameworks  49

Principles, Technologies, and Methods of Geographic Information Systems  102

In recent years, Geographic Information Systems (GIS) have undergone rapid development in both theoretical and practical dimensions. GIS has been widely applied for modeling and decision-making support across various fields such as urban management, regional planning, and environmental remediation, establishing geographic information as a vital component of the information era. The introduction of the “Digital Earth” concept has further accelerated the advancement of GIS, which serves as its technical foundation. Concurrently, scholars have been dedicated to theoretical research in areas like spatial cognition, spatial data uncertainty, and the formalization of spatial relationships. This reflects the dual nature of GIS as both an applied technology and an academic discipline, with the two aspects forming a mutually reinforcing cycle of progress.

WEB Technology  258

Systems  232

Programming Language  353