projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 3618a2cd KM |
1 | .\" Copyright (c) 1983 Regents of the University of California. |
| 2 | .\" All rights reserved. The Berkeley software License Agreement | |
| 3 | .\" specifies the terms and conditions for redistribution. | |
| 4 | .\" | |
| 59513cc8 | 5 | .\" @(#)traper.3 6.1 (Berkeley) %G% |
| 3618a2cd | 6 | .\" |
| 59513cc8 | 7 | .TH TRAPER 3F "" |
| 3618a2cd KM |
8 | .UC 5 |
| 9 | .SH NAME | |
| 10 | traper \- trap arithmetic errors | |
| 11 | .SH SYNOPSIS | |
| 12 | .B integer function traper (mask) | |
| 13 | .SH DESCRIPTION | |
| 14 | \fBNOTE: This routine applies only to the \s-2VAX\s0. | |
| 15 | It is ignored on the \s-2PDP11\s0.\fR | |
| 16 | .PP | |
| 17 | Integer overflow and floating point underflow are not normally | |
| 18 | trapped during execution. This routine enables these traps by setting | |
| 19 | status bits in the process status word. These bits are reset on | |
| 20 | entry to a subprogram, and the previous state is restored on return. | |
| 21 | Therefore, this routine must be called | |
| 22 | .I inside | |
| 23 | each subprogram in which these conditions should be trapped. | |
| 24 | If the condition occurs and trapping is enabled, | |
| 25 | signal SIGFPE is sent to the process. (See | |
| 26 | .IR signal (3C)) | |
| 27 | .PP | |
| 28 | The argument has the following meaning: | |
| 29 | .nf | |
| 30 | ||
| 31 | value meaning | |
| 32 | 0 do not trap either condition | |
| 33 | 1 trap integer overflow only | |
| 34 | 2 trap floating underflow only | |
| 35 | 3 trap both the above | |
| 36 | ||
| 37 | .fi | |
| 38 | The previous value of these bits is returned. | |
| 39 | .SH FILES | |
| 40 | .ie \nM /usr/ucb/lib/libF77.a | |
| 41 | .el /usr/lib/libF77.a | |
| 42 | .SH "SEE ALSO" | |
| 43 | signal(3C), signal(3F) |