uac(1) — Commands
NAME
uac − Unaligned Access Message Control
SYNOPSIS
uac s | p [value]
FLAGS
The following flags are used with the uac command:
sSets or displays the current flag setting for the system.
pSets or displays the current flag setting for the parent process.
DESCRIPTION
Most complete instruction set computers (CISC) can access unaligned data but only at a significantly reduced speed. Most reduced instruction set computers (RISC) do not attempt to handle unaligned accesses, but, instead, generate an "Unaligned Access Trap" and let the operating system handle the fault.
The default action for unaligned access traps for the operating system is for the operating system to fix the unaligned access and then display a warning to the user that an unaligned access has occurred. This provides an opportunity to correct the code so that unaligned access is prevented.
These defaults are satisfactory for most users, but some users require a different behavior and want to specify their own Unaligned Access Control (hence called "UAC").
The uac command enables or disables the "Fixed up unaligned data access for pid nnn at pc 0xAddr" messages that are displayed. The command sets or displays the UAC_NOPRINT flag, which determines if the messages for the system or the parent process of the user are displayed. Usually, the parent process is the shell.
If value is not specified, the current flag setting is displayed. You can specify value as either 0 (zero) or 1 (one). If value is 0 (zero), the flag is turned on and messages are not displayed. If value is 1 (one), the flag is turned off and messages are displayed.
RESTRICTIONS
You must be superuser to set the system flag.
EXAMPLES
The following command disables messages for the parent process:
# uac p 0
The following command enables messages for the system:
# uac s 1