TERMDEF(3,L) AIX Technical Reference TERMDEF(3,L) ------------------------------------------------------------------------------- termdef PURPOSE Queries terminal characteristics. LIBRARY Standard C Library (libc.a) SYNTAX char *termdef (fildes, c) int fildes; char c; DESCRIPTION The termdef subroutine returns a pointer to a null-terminated static character string that identifies a characteristic of the terminal that is open on the file descriptor specified by the fildes parameter. The c parameter specifies the characteristic that is to be queried. termdef determines this information by performing the following actions: 1. It queries the terminal device, using the Query HFT Device command, which is discussed on page hft-28. 2. If the query fails, then termdef uses the value of an environment variable. 3. If the environment variable is not set, then termdef returns the default value specified in the following table. The following list shows the valid request types and the corresponding environment variables that are used if the Query HFT Device command fails: Environment Default c Variable Value Description t TERM "ibm5151" The terminal type l LINES NULL The number of lines or rows, based on the current font c COLUMNS NULL The number of character columns, based on the current font. Note: When fildes identifies an asynchronous terminal, the Query HFT Device command always fails and the environment variable is always checked. The TERM variable is automatically set each time you log in. LINES and COLUMNS need to be set only if: Processed July 12, 1991 TERMDEF(3,L) 1 TERMDEF(3,L) AIX Technical Reference TERMDEF(3,L) o You are using an asynchronous terminal and want to override the lines and cols settings in the terminfo data base, or o Your asynchronous terminal has an unusual number of lines or columns and you are running an application that uses termdef, but not terminfo. This is true because the terminfo initialization subroutine, setupterm, calls termdef to determine the number of lines and columns on the display. If termdef cannot supply this information, then setupterm uses the values in the terminfo data base. RELATED INFORMATION "Terminfo Level Subroutines," "terminfo," and "Query HFT Device Command." The display and termdef commands in AIX Operating System Commands Reference. Processed July 12, 1991 TERMDEF(3,L) 2