This help facility provides information on the support provided by ESL's DOS Command Line Interface library.

Overview

The DOS Shell library provides a set of routines to enable your application to perform any DOS command, providing an alternative to the local application "DOSCMD.exe". Like the local application, the DOS Shell library, allows command strings to be passed to the operating system shell, as if they there had been typed into a Command Window. The response from the command is then received into the ESL application, so data can be parsed and appropriated action taken.

History

The DOS Shell library provides an alternative to the local application "DOSCMD.exe", which was developed as a simple migration facility, as the OS/2 version of ESL (known at the time as Easel/32) was able to interface directly with OS/2's command line interpreter. Before the introductions of the Extended Call Interface (e.g. ECI), which allows ESL to call any System Function, it was a common practise to use the use the Operating System Command shell to retrieve system information, or execute commands, for example "deleting a file". Due to the use of Dynamic Data Exchange (i.e. DDE), used to communication with all local applications, the "DOSCMD.exe" approach is limited to simple DOS commands. This DOS Shell library removes the need to use DDE, therefore allows all DOS commands to be supported.

With the introduction of the ECI, we would recommend the appropriate System API be used instead of either DOSCMD or this DOS Shell library and suggest ESL Developers review the OSUtil sample, as it demonstrates how System APIs can be used, and may even have the required feature already available.