Emulator High-level Language Application Program Interface (EHLLAPI) is an enhanced version of HLLAPI. It was introduced in 1986 by the IBM

IBM

International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...

 company and it provided functions that can access the user interface data for text-based applications.

EHLLAPI can be used to determine screen characters, track and send keystrokes, check the host status and perform file transfers. Typically this API was employed for communication with existing mainframe applications without
the need to modify the application code. EHLLAPI could map a screen between different IBM 3270

IBM 3270

The IBM 3270 is a class of block oriented terminals made by IBM since 1972 normally used to communicate with IBM mainframes. As such, it was the successor to the IBM 2260 display terminal. Due to the text colour on the original models, these terminals are informally known as green screen terminals...

 legacy applications, allowing information to be transferred between the two. It was often used for automated control of applications via keystroke input and screen scraping.

This IBM standard is supported by most terminal emulators.