/* vim: tabstop=4 shiftwidth=4 noexpandtab
 * This file is part of ToaruOS and is released under the terms
 * of the NCSA / University of Illinois License - see LICENSE.md
 * Copyright (C) 2013-2018 K. Lange
 *
 * kill - Send a signal to a process
 *
 * Supports signal names like any mature `kill` should.
 */
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <ctype.h>
#include <errno.h>

struct sig_def {
	int sig;
	const char * name;
};

struct sig_def signals[] = {
	{SIGHUP,"HUP"},
	{SIGINT,"INT"},
	{SIGQUIT,"QUIT"},
	{SIGILL,"ILL"},
	{SIGTRAP,"TRAP"},
	{SIGABRT,"ABRT"},
	{SIGEMT,"EMT"},
	{SIGFPE,"FPE"},
	{SIGKILL,"KILL"},
	{SIGBUS,"BUS"},
	{SIGSEGV,"SEGV"},
	{SIGSYS,"SYS"},
	{SIGPIPE,"PIPE"},
	{SIGALRM,"ALRM"},
	{SIGTERM,"TERM"},
	{SIGUSR1,"USR1"},
	{SIGUSR2,"USR2"},
	{SIGCHLD,"CHLD"},
	{SIGPWR,"PWR"},
	{SIGWINCH,"WINCH"},
	{SIGURG,"URG"},
	{SIGPOLL,"POLL"},
	{SIGSTOP,"STOP"},
	{SIGTSTP,"TSTP"},
	{SIGCONT,"CONT"},
	{SIGTTIN,"TTIN"},
	{SIGTTOUT,"TTOUT"},
	{SIGVTALRM,"VTALRM"},
	{SIGPROF,"PROF"},
	{SIGXCPU,"XCPU"},
	{SIGXFSZ,"XFSZ"},
	{SIGWAITING,"WAITING"},
	{SIGDIAF,"DIAF"},
	{SIGHATE,"HATE"},
	{SIGWINEVENT,"WINEVENT"},
	{SIGCAT,"CAT"},
	{0,NULL},
};

void usage(char * argv[]) {
	printf(
			"%s - send a signal to another process\n"
			"\n"
			"usage: %s [-\033[3mx\033[0m] \033[3mprocess\033[0m\n"
			"\n"
			" -h --help       \033[3mShow this help message.\033[0m\n"
			" -\033[3mx\033[0m              \033[3mSignal number to send\033[0m\n"
			"\n",
			argv[0], argv[0]);
}

int main(int argc, char * argv[]) {
	int signum = SIGKILL;
	int pid = 0;
	int i = 1;

	if (argc < 2) {
		usage(argv);
		return 1;
	}

	if (argv[1][0] == '-') {
		signum = -1;
		if (strlen(argv[1]+1) > 3 && strstr(argv[1]+1,"SIG") == (argv[1]+1)) {
			struct sig_def * s = signals;
			while (s->name) {
				if (!strcmp(argv[1]+4,s->name)) {
					signum = s->sig;
					break;
				}
				s++;
			}
		} else {
			if (!isdigit(argv[1][1] < '0')) {
				struct sig_def * s = signals;
				while (s->name) {
					if (!strcmp(argv[1]+1,s->name)) {
						signum = s->sig;
						break;
					}
					s++;
				}
			} else {
				signum = atoi(argv[1]+1);
			}
		}
		if (signum == -1) {
			fprintf(stderr,"%s: %s: invalid signal specification\n",argv[0],argv[1]+1);
			return 1;
		}
		i++;
	}

	if (i < argc) {
		pid = atoi(argv[i]);
		if (pid) {
			if (kill(pid, signum) < 0) {
				fprintf(stderr, "%s: (%d) %s\n", argv[0], pid, strerror(errno));
			}
		} else {
			fprintf(stderr, "%s: invalid pid (%s)\n", argv[0], argv[i]);
		}
	} else {
		usage(argv);
		return 1;
	}

	return 0;
}