Unlike the PCDOS and OS/2 versions, a system abort function is installed by vv_init() in the terminal-based versions of Vermont Views. The function installed as the system abort function is vv_abort(), which calls vv_exit() and exit().
vv_abort() is called when an abort condition is detected in a call to ki() or ki_chk(). The following are interpreted as abort conditions:
| UNIX | An INTR signal is received. This is usually the result of the user pressing the DELETE key. |
| VMS | Ctrl-C or Ctrl-Y is read from the keyboard. |
Use se_abortfp() if you want to install your own system abort function or disable the abort key(s). If you install NULLFP as the abort function, ki() and ki_chk() will return 257 when either Ctrl-C or Ctrl-Y is read under VMS. No value is returned on receipt of an INTR signal under UNIX.
If you have installed another abort function and want to reinstall the system abort function, call:
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Abort-key processing is not immediate in VMS or PCDOS. Abort keys are processed as they are read by the program, rather than as they are entered by the user. Consequently, if a program does not read the keyboard, the user will be unable to terminate the program from the terminal.
Abort-key processing is immediate under UNIX.
For more information about writing and installing abort functions, see Chapter 40, "Writing Keyloop, Key Filter and Abort Functions."
