REXX is a high-level programming language that was developed in the 1970s by IBM. REXX, which stands for Restructured Extended Executor, was designed to be easy to learn and use, making it an ideal language for beginners. REXX is a scripting language, which means that it is used to automate tasks and write scripts that can be executed on various platforms.
Chapter 1: Getting Started with REXX
REXX is an interpreted language, which means that you do not need to compile your code before executing it. This makes it very easy to get started with REXX programming. To start writing REXX code, you will need a text editor and a REXX interpreter. REXX interpreters are available for most operating systems, including Windows, macOS, and Linux.
Chapter 2: Writing REXX Code
REXX code is made up of statements that perform specific tasks. A statement in REXX is usually a single line of code that ends with a semicolon. REXX code is case-insensitive, which means that you can use uppercase or lowercase letters interchangeably.
One of the most common tasks that REXX is used for is manipulating strings. REXX has built-in functions for string manipulation, including concatenation, substring extraction, and search and replace. Here's an example of a REXX program that concatenates two strings:
```
/* This program concatenates two strings */
s1 = "Hello, "
s2 = "World!"
result = s1 || s2
say result
```
In this program, we define two strings `s1` and `s2` and concatenate them using the `||` operator. The result is then printed to the screen using the `say` command.
Chapter 3: Applications of REXX
REXX is a versatile language that can be used for a variety of applications, including system administration, text processing, and web development. One of the most popular applications of REXX is in IBM mainframe systems, where it is used for automation and scripting. REXX is also used in the open-source operating system, Linux, where it is used for system administration and shell scripting.
Another popular application of REXX is in web development. REXX can be used to create dynamic web pages and web applications. REXX can also be used to automate web tasks, such as web scraping and data extraction.
Conclusion:
REXX is a powerful and versatile programming language that is easy to learn and use. With its built-in string manipulation functions and versatility, it can be used for a variety of applications. Whether you are a beginner or an experienced programmer, REXX is definitely worth considering for your next project.