kill: add -q sigval to use sigqueue(2)

Signed-off-by: Karel Zak <kzak@redhat.com>

configure.ac

@@ -195,6 +195,7 @@ AC_CHECK_FUNCS(
 	getdtablesize \
 	getexecname \
 	getrlimit \
+	sigqueue \
 	srandom \
 	setresgid \
 	setresuid \

misc-utils/Makefile.am

@@ -120,7 +120,7 @@ endif
 
 if BUILD_KILL
 bin_PROGRAMS += kill
-kill_SOURCES = kill.c procs.c kill.h
+kill_SOURCES = kill.c procs.c kill.h $(top_srcdir)/lib/strutils.c
 dist_man_MANS += kill.1
 endif
 

misc-utils/kill.1

@@ -8,6 +8,8 @@ kill \- terminate a process
 .B kill
 .RB [ \-s
 .IR signal  | \fB\-p\fP ]
+.RB [ \-q
+.IR sigval ]
 .RN [ \-a ]
 .RB [ \-\- ]
 .IR pid ...
@@ -84,6 +86,17 @@ Specify that
 .B kill
 should only print the process id (pid)
 of the named processes, and not send any signals.
+.TP
+.BI \-q " sigval"
+Use
+.BR sigqueue (2)
+rather than
+.BR kill (2)
+and the sigval argument is used to specify an integer to be sent with the
+signal.  If the receiving process has installed a handler for this signal using
+the SA_SIGINFO flag to
+.BR sigaction (2),
+then it can obtain this data via the si_value field of the siginfo_t structure.
 .SH "SEE ALSO"
 .BR bash (1),
 .BR tcsh (1),

misc-utils/kill.c

@@ -53,6 +53,7 @@
 #include "c.h"
 #include "kill.h"
 #include "nls.h"
+#include "strutils.h"
 
 struct signv {
 	char *name;
@@ -152,6 +153,11 @@ extern int *get_pids (char *, int);
 
 static char *progname;
 
+#ifdef HAVE_SIGQUEUE
+static int use_sigval;
+static union sigval sigdata;
+#endif
+
 int main (int argc, char *argv[])
 {
     int errors, numsig, pid;
@@ -231,6 +237,17 @@ int main (int argc, char *argv[])
 	    }
 	    continue;
 	}
+	if (! strcmp (arg, "-q")) {
+	    if (argc < 2)
+		return usage (1);
+	    argc--, argv++;
+	    arg = *argv;
+#ifdef HAVE_SIGQUEUE
+	    sigdata.sival_int = strtol_or_err(arg, _("failed to parse sigval"));
+	    use_sigval = 1;
+#endif
+	    continue;
+	}
 	/*  `arg' begins with a dash but is not a known option.
 	    so it's probably something like -HUP, or -1/-n
 	    try to deal with it.
@@ -403,11 +420,20 @@ int usage (int status)
 
 int kill_verbose (char *procname, int pid, int sig)
 {
+    int rc;
+
     if (sig < 0) {
 	printf ("%d\n", pid);
 	return 0;
     }
-    if (kill (pid, sig) < 0) {
+#ifdef HAVE_SIGQUEUE
+    if (use_sigval)
+	rc = sigqueue(pid, sig, sigdata);
+    else
+#endif
+	rc = kill (pid, sig);
+
+    if (rc < 0) {
 	fprintf (stderr, "%s ", progname);
 	perror (procname);
 	return 1;