It is always better to use man pages to get more information.
See ksh man page for trap command.
% trap [arg] [sig ...]
arg is a command read and executed when the shell
receives signal(s) sig. (Note that arg is scanned once
when the trap is set and once when the trap is taken.)
Each sig can be given as a number or name of the
signal. Trap commands are executed in signal number
order. Any attempt to set a trap on a signal that was
ignored upon entering the current shell has no effect.
If arg is omitted or is -, all traps for sig are reset
to their original values. If arg is the null string,
this signal is ignored by the shell and by the commands
it invokes. If sig is DEBUG, arg is executed after
each command. If sig is ERR, arg is executed whenever
a command has a non-zero exit code. If sig is 0 or
EXIT and the trap statement is executed inside the body
of a function, the command arg is executed after the
function completes. If sig is 0 or EXIT for a trap set
outside any function, the command arg is executed on
exit from the shell. The trap command with no
arguments prints a list of commands associated with
each signal number.
--
Muthu
Easy to suggest when don't know about the problem!
