Boa tarde nobres colegas,
Pesquisando na raiz do código fonte do Harbour encontrei algo sobre tratamento de signal, talvez o Harbour até trate de alguma forma, não sei se da forma que pretendia, mas de qualquer forma enviei um e-mail para o Vailton falando dessa possibilidade.
Segue o que encontrei...
roberto@linux-br8r:~/C/hbv34s> grep -inr "signal.h"
contrib/xhb/hbserv.ch:60:/* Signal handler return types */
contrib/xhb/hbserv.ch:67: signal handler as a parameter
contrib/xhb/hbserv.c:71:/* TODO: Haiku will supposedly do this later on, read /boot/develop/headers/posix/signal.h */
contrib/xhb/hbserv.c:76:#include <signal.h>
contrib/xhb/hbserv.c:109:/* Unix specific signal handling implementation
contrib/xhb/hbserv.c:149: /* let's find the right signal handler. */
contrib/xhb/hbserv.c:152: /* avoid working if PRG signal handling has been disabled */
contrib/xhb/hbserv.c:177: a little dangerous. But we are in a signal hander...
contrib/xhb/hbserv.c:229: calling pthread exit from a signal handler will cause infinite wait for
contrib/xhb/hbserv.c:307: /* reset signal handling; this is done here (so I don't
contrib/xhb/hbserv.c:319: ATM we don't care very much about signal handling during
contrib/xhb/hbserv.c:406: /* let's find the right signal handler. */
contrib/xhb/hbserv.c:409: /* avoid working if PRG signal handling has been disabled */
contrib/xhb/hbserv.c:434: a little dangerous. But we are in a signal hander...
contrib/xhb/hbserv.c:563: * remove the signal handlers, and do it in a mutltiplatform fashon. Use this
contrib/xhb/hbserv.c:567:/* Set the signal handlers to our program interceptors. */
contrib/xhb/hbserv.c:641:/* Reset the signal handlers to the default OS value */
contrib/xhb/hbserv.c:698: * Initializes signal handler system
contrib/xhb/hbserv.c:796: /* reset default signal handling */
contrib/xhb/hbserv.c:900: * issued to signal handling routines. This is system dependant.
ChangeLog.txt:90410: + Adding more signal handlers plus some other mods.
ChangeLog.txt:156019: we should introduce a new variable to signal Harbour
ChangeLog.txt:199199: ! include signal.h in all *nixes builds - it was my typo and not only
utils/hbmk2/hbmk2.prg:9894: "signal.h" =>, ;
src/3rd/zlib/zlib.h:76: The library does not install any signal handler. The decoder checks
src/rtl/gtpca/gtpca.c:77:# include <signal.h>
src/rtl/gtos2/gtos2.c:108: #include <signal.h>
src/rtl/gtcrs/gtcrs.h:96:#include <signal.h>
src/rtl/gttrm/gttrm.c:83:# include <signal.h>
src/rtl/gttrm/gttrm.c:396:/* static variables use by signal handler */
src/rtl/gtstd/gtstd.c:70:# include <signal.h>
src/rtl/gtsln/gtsln.h:72:#include <signal.h>
src/rtl/gtxwc/gtxwc.h:70:#include <signal.h>
src/rtl/gtxwc/gtxwc.c:4945: /* for signal handler */
src/rtl/hbproces.c:60:# include <signal.h>
src/rtl/gtdos/gtdos.c

#include <signal.h>
src/rtl/hbinet.c:111: #include <signal.h>
src/vm/extrap.c:58: #include <signal.h>
A todos um muito obrigado e um exelente fim de semana.