Microsoft KB Archive/10365

DEL Key Interrupts Process, XENIX

PSS ID Number: Q10365 Article last modified on 11-16-1992

2.10 2.20 XENIX

Problem: If the key labeled DEL in the lower-right corner of the numeric keypad on the IBM AT keyboard is pressed while a XENIX COBOL program is running, it has the same effect as pressing CTRL-. The message “Stopped by Interrupt Key” is generated and the program halts. This is a problem because someone can easily terminate a program in the middle of a critical file update by accidentally pressing the DEL key. It is helpful to have the CTRL- work; however, the DEL key needs to disabled.

Response: A method for aborting out of a program is desirable. Providing an interrupt key is a good method because it gives the COBOL run time a chance to leave files in a clean state (all file buffers are flushed and closed when the interrupt key is pressed). If an interrupt key were not implemented, you would have to power down to get out of a program. There would be no other means of escape. You have complete control over what character is used for the interrupt key. The command “stty intr CHAR” may be used to to set the interrupt key to the character “CHAR.” For more information, see the Commands (C), stty (C) section in the “XENIX System /286 Operating System Reference Manual Volume II.” You also have complete control over what keys are used for editing when running a COBOL program. You can change the editing keys by modifying the termcap file. Please note that “/etc/termcap” is the default termcap file. You may use any file as the termcap file by setting the environment variable “TERMCAP” to the full pathname of the file to be used. See Appendix D of the “Microsoft COBOL Compiler for XENIX: User’s Guide” for more information. To make the environment identical to MS-DOS, do the following: 1. Set the interrupt character to CTRL-C, as follows: * stty intr ‘^C’ 2. Set the character delete key to DEL, as follows: Copy /etc/termcap to another file (say /usr/JohnDoe/termcap) cp /etc/termcap /usr/JohnDoe/termcap 3. Edit the termcap file, by adding the string DE=^? to the capabilities of the terminal to be used. 4. Set the environment variables as follows: a. For CSH users, do the following: * setenv TERMCAP /usr/JohnDoe/termcap * setenv TERM whatever b. For BOURNE SHELL (SH) users, do the following: * set TERMCAP /usr/JohnDoe/termcap * export TERMCAP * set TERM whatever * export TERM The entries marked by an asterisk (*) must either be done every time you log in, or they may be put in your .login or .profile file.

Copyright Microsoft Corporation 1992.