void
psignal(
unsigned sig
, const char *s
)
)
function locates the descriptive message
string for the given signal number
sig
and writes it to the standard error.
If the argument
s
is
non-NULL
it is written to the standard error file descriptor
prior to the message string,
immediately followed by a colon and a space.
If the signal number is not recognized
(sigaction(2)),
the string
``Unknown signal''
is produced.
The message strings can be accessed directly using the external array
sys_siglist,
indexed by recognized signal numbers.
The external array
sys_signame
is used similarly and contains short, upper-case abbreviations for signals
which are useful for recognizing signal names in user input.
The defined variable
NSIG
contains a count of the strings in
sys_siglist
and
sys_signame.
)
function appeared in
4.2BSD.