Experix: Открытый интерпретатор для управления лабораторным оборудованием

Experix is an open source command interpreter designed for operating laboratory equipment, especially data acquisition devices, and processing, displaying and storing the data from them. It is usable now, only under Linux on the x86 architecture, but still under development, and users are welcome to participate in extending and improving it. Experix is radically different from most
commercial data acquisition programs, for example LabVIEW, which model a measurement and control application as a network of operational units represented graphically as boxes with connections that stand for data flow. In these systems an application is created by manipulating these symbols on the screen, and then it is used by clicking buttons and filling dialog boxes in a GUI environment. Experix, in contrast, represents the application as a series of operations generally taking place one after another. It processes a command line in a sequential way, and numbers, operators, functions and commands in the command line consume and create objects on a stack. These objects include integers and floating point numbers in several sizes, complex and polar numbers, multi dimensional arrays made from any of the numerical types, several kinds of strings, and pointers to functions, commands and variables (which can be numbers, arrays and strings). A function, command or operator requires certain types of objects on the stack and puts objects on the stack, and may also change values in stack objects and variables, draw graphs, order operations in device drivers, and read and write files. Experix is released under the GNU GPL.

Documentation is extensive. The keywords. doc file describes functions and data structures in the program. Commands, functions and operators are described in help files, which are accessed in experix by the help operators. Help files are ordinary text files with terminal escape sequences to provide color highlights. System commands such as cat and grep will show these files with their colorization, and the editor that experix uses for the two question mark help operator is nano (from the GNU project) with the escape sequence extension. The source files for nano that were changed to provide this extension are available on the experix website. Experix users are encouraged to correct and improve help files as they work.

Currently, experix is only available for Linux and, due to assembly language code, only on the x86 architecture. At present the only graphics support for experix is with the open source SVGALib. It is possible to have an experix graphics session in one virtual terminal and text or X sessions in others, and switch between them with the keys. Graphics operations are done by a server process, and experix sends commands and data to this process through a fifo. It has an execution thread that uses readline (an open source library from the GNU project) to obtain command lines and place them in the execution queue. Another thread translates the standard output (i. e. the echo from readline) into graphics server commands. Experix can also run in a text screen or X term without using svgalib at all. There is some assembly code and other matters to attend to before it can run on architectures other than x86. The range of device drivers and applications available now is extremely limited. It runs as root, which is a considerable security hazard on a networked computer. It should be possible to run experix without root privileges, but this has not yet been done.