Simplify

Signed-off-by: Mattias Andrée <maandree@kth.se>

1 files changed, 166 insertions, 0 deletions

diff --git a/pdeath.c b/pdeath.c
new file mode 100644
index 0000000..2cdbee2
--- /dev/null
+++ b/pdeath.c
@@ -0,0 +1,166 @@
+/* See LICENSE file for copyright and license details. */
+#include <sys/prctl.h>
+#include <errno.h>
+#include <limits.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <unistd.h>
+
+struct sig {
+	int signo;
+	const char *name;
+} sigs[] = {
+	{SIGHUP,    "HUP"},
+	{SIGINT,    "INT"},
+	{SIGQUIT,   "QUIT"},
+	{SIGILL,    "ILL"},
+	{SIGTRAP,   "TRAP"},
+	{SIGABRT,   "ABRT"},
+	{SIGIOT,    "IOT"},
+	{SIGBUS,    "BUS"},
+	{SIGFPE,    "FPE"},
+	{SIGKILL,   "KILL"},
+	{SIGUSR1,   "USR1"},
+	{SIGSEGV,   "SEGV"},
+	{SIGUSR2,   "USR2"},
+	{SIGPIPE,   "PIPE"},
+	{SIGALRM,   "ALRM"},
+	{SIGTERM,   "TERM"},
+	{SIGSTKFLT, "TKFLT"},
+	{SIGCLD,    "CLD"},
+	{SIGCHLD,   "CHLD"},
+	{SIGCONT,   "CONT"},
+	{SIGSTOP,   "STOP"},
+	{SIGTSTP,   "TSTP"},
+	{SIGTTIN,   "TTIN"},
+	{SIGTTOU,   "TTOU"},
+	{SIGURG,    "URG"},
+	{SIGXCPU,   "XCPU"},
+	{SIGXFSZ,   "XFSZ"},
+	{SIGVTALRM, "VTALRM"},
+	{SIGPROF,   "PROF"},
+	{SIGWINCH,  "WINCH"},
+	{SIGPOLL,   "POLL"},
+	{SIGIO,     "IO"},
+	{SIGPWR,    "PWR"},
+	{SIGSYS,    "SYS"},
+	{SIGUNUSED, "UNUSED"},
+	{0,         NULL}
+};
+
+const char *argv0;
+
+static void
+usage(void)
+{
+	fprintf(stderr, "usage: %s (-L | (signal)[(+|-)off] command [argument] ...)\n", argv0);
+	exit(127);
+}
+
+static void
+invalid_signal(void)
+{
+	fprintf(stderr, "%s: invalid signal\n", argv0);
+	exit(127);
+}
+
+static void
+print_signals(void)
+{
+	struct sig *sig = sigs;
+	for (; sig->name; sig++)
+		printf("%s\n", sig->name);
+	printf("RTMIN\nRTMAX\n");
+}
+
+static int
+strict_strtoi(const char *str, int min, int max)
+{
+	char *end;
+	long int ret;
+	errno = 0;
+	ret = strtol(str, &end, 10);
+	if (errno || *end)
+		usage();
+	if (ret < min || ret > max)
+		invalid_signal();
+	return (int)ret;
+}
+
+static int
+get_signal(const char *str)
+{
+	struct sig *sig = sigs;
+	int have_prefix = 0;
+	char *end;
+	long int ret;
+	if (!strncasecmp(str, "SIG", 3)) {
+		str += 3;
+		have_prefix = 1;
+	}
+	if (!strcasecmp(str, "RTMIN"))
+		return SIGRTMIN;
+	if (!strcasecmp(str, "RTMAX"))
+		return SIGRTMAX;
+	for (; sig->name; sig++) {
+		if (!strcasecmp(str, sig->name))
+		  return sig->signo;
+	}
+	if (!have_prefix) {
+		errno = 0;
+		ret = strtol(str, &end, 10);
+		if (!errno && !*end && 0 <= ret && ret < _NSIG)
+			return (int)ret;
+
+	}
+	invalid_signal();
+	return -1;
+}
+
+int
+main(int argc, char *argv[])
+{
+	char *off;
+	char sign = '\0';
+	int signo;
+
+	argv0 = *argv ? (argc--, *argv++) : "pdeath";
+
+	if (*argv && **argv == '-') {
+		if (argc == 1 && !strcmp(*argv, "-L")) {
+			print_signals();
+			if (fflush(stdout) || fclose(stdout)) {
+				perror(argv0);
+				return 127;
+			}
+			return 0;
+		}
+		usage();
+	}
+
+	if (argc < 2)
+		usage();
+
+	if ((off = strpbrk(*argv, "+-"))) {
+		sign = *off;
+		*off++ = '\0';
+	}
+	signo = get_signal(*argv);
+	if (sign == '-')
+		signo -= strict_strtoi(off, 0, signo);
+	else if (sign == '+')
+		signo += strict_strtoi(off, 0, _NSIG - 1 - signo);
+	argv++, argc--;
+
+	if (prctl(PR_SET_PDEATHSIG, signo) == -1) {
+		perror(argv0);
+		return 127;
+	}
+
+	execvp(*argv, argv);
+	fprintf(stderr, "%s: %s: %s\n", argv0, strerror(errno), *argv);
+	return 127;
+}