The environments that may be specified for command execution are system-dependent. Use the address function to find out what the current environment is. Any, all or none of the three clauses with input , with output , and with error may be specified. They may be specified in any order. When using an array, element 0 should state the number of elements for input. Element 0 tells how many lines of output there are for output or error. Use file sortin. Specify both arrays as compound variable stems include the period after the array name.
Before issuing the command, you must set Element 0 in the input array to the number of items in the input array. After the command, the number of elements in the output array will be in Element 0 of that array.
If on is specified, call enables the error condition and optionally specifies the name of the exception routine that will be invoked when it is raised. The condition must be one of error , failure , halt , and notready. Specifying off disables an error condition.
If neither on nor off is specified, call invokes an internal, built-in or external routine. Coding the routine name in quotes prevents searching for an internal routine. Zero, one, or more expression arguments may be passed to the routine. If the routine returns a result, the special variable result is set to that value.
Otherwise result is set to uninitialized. Loop control variables can be altered from within the loop and the leave , iterate , signal , return , and exit instructions may also modify loop behavior. We just show the DO here. The expression must evaluate to either 0 or 1. This is a great benefit because you can select the interpreter you like -- one optimized for speed, extended for a particular operating system, or whatever.
The main downside is that not every free tool works with every interpreter. Yes, among them Regina and ooRexx. See the Downloads page for information and download links. Yes, Rexx runs on most handheld operating systems, see here and here. Every free Rexx interpreter at least conforms to TRL The single exception is NetRexx, a "Rexx-like" language designed to integrate into the Java environment. Rexx's standardization yields portable code and renders your Rexx skills transferable across systems.
Is Rexx a "scripting language" or "command language"? When Rexx was invented twenty years ago, IBM termed it a " command language " or "command procedures language" because it is excellent for issuing and managing operating system commands. Today most people call such languages " scripting languages.
Either terminology can be used. Rexx can be called either a scripting language or a command language. Yes, both. A macro language is a scripting language that provides programmability within some other software product. Rexx is a macro language for many products. Rexx is easy because it is a free-form, English-like language that requires almost no syntax this contrasts to the Unix shell languages and Perl, which use almost every symbol on the keyboard.
Rexx has a very small instruction set, surrounded by a rich function set. You can start programming right away and expand your knowledge of the language's functions at your own pace. Many free tools for Rexx come in the form of "external function libraries. Rexx is powerful due to its large built-in function library, its easy extensibility by external function packages, its integration and extension through standard interfaces to other languages like C, its string manipulation capabilities, and its huge set of free add-on tools.
Anything you can do in any other scripting language, you can do in Rexx. Rexx looks easy to code in. Won't I run out of power using such an easy language?
No, Rexx is easily extensible and offers thousands of free add-on tools. It's a power language. The article " Power through Simplicity " explains how power can be based in languages that "look" simple and the advantages to this approach to power programming over languages that "look" powerful. It's easy to transition into object-oriented Rexx programming because the object-oriented interpreters are true supersets of the procedural language.
The data from the file is sent to the sort command. The output of the sort command is then sent to the sortout. This method is used to find out what is the default environment used for the Input, Error and Output streams. Rexx - System Commands Advertisements.
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