/* $Id$
   Copyright 2007, Red Hat Inc.  */

#include <stdio.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>

#include <asm/unistd.h>
#include <unistd.h>
#define tkill(tid, sig) syscall (__NR_tkill, (tid), (sig))

#define LENGTH(x) (sizeof (x) / sizeof (*(x)))

struct signal
  {
    int signo;
    const char *name;
  };
static const struct signal sigtab[] =
  {
#ifdef SIG0
    { SIG0, "0" },
#endif
#ifdef SIGHUP
    { SIGHUP, "HUP" },
#endif
#ifdef SIGINT
    { SIGINT, "INT" },
#endif
#ifdef SIGQUIT
    { SIGQUIT, "QUIT" },
#endif
#ifdef SIGILL
    { SIGILL, "ILL" },
#endif
#ifdef SIGTRAP
    { SIGTRAP, "TRAP" },
#endif
#ifdef SIGABRT
    { SIGABRT, "ABRT" },
#endif
#ifdef SIGBUS
    { SIGBUS, "BUS" },
#endif
#ifdef SIGFPE
    { SIGFPE, "FPE" },
#endif
#ifdef SIGKILL
    { SIGKILL, "KILL" },
#endif
#ifdef SIGUSR1
    { SIGUSR1, "USR1" },
#endif
#ifdef SIGSEGV
    { SIGSEGV, "SEGV" },
#endif
#ifdef SIGUSR2
    { SIGUSR2, "USR2" },
#endif
#ifdef SIGPIPE
    { SIGPIPE, "PIPE" },
#endif
#ifdef SIGALRM
    { SIGALRM, "ALRM" },
#endif
#ifdef SIGTERM
    { SIGTERM, "TERM" },
#endif
#ifdef SIGSTKFLT
    { SIGSTKFLT, "STKFLT" },
#endif
#ifdef SIGCHLD
    { SIGCHLD, "CHLD" },
#endif
#ifdef SIGCONT
    { SIGCONT, "CONT" },
#endif
#ifdef SIGSTOP
    { SIGSTOP, "STOP" },
#endif
#ifdef SIGTSTP
    { SIGTSTP, "TSTP" },
#endif
#ifdef SIGTTIN
    { SIGTTIN, "TTIN" },
#endif
#ifdef SIGTTOU
    { SIGTTOU, "TTOU" },
#endif
#ifdef SIGURG
    { SIGURG, "URG" },
#endif
#ifdef SIGXCPU
    { SIGXCPU, "XCPU" },
#endif
#ifdef SIGXFSZ
    { SIGXFSZ, "XFSZ" },
#endif
#ifdef SIGVTALRM
    { SIGVTALRM, "VTALRM" },
#endif
#ifdef SIGPROF
    { SIGPROF, "PROF" },
#endif
#ifdef SIGWINCH
    { SIGWINCH, "WINCH" },
#endif
#ifdef SIGIO
    { SIGIO, "IO" },
#endif
#ifdef SIGPWR
    { SIGPWR, "PWR" },
#endif
#ifdef SIGSYS
    { SIGSYS, "SYS" },
#endif
#ifdef disableSIGRTMIN	/* initializer element is not constant */
    { SIGRTMIN, "RTMIN" },
#endif
#ifdef disableSIGRTMAX	/* initializer element is not constant */
    { SIGRTMAX, "RTMAX" },
#endif
  };

static void list (void)
{
  const struct signal *sig;

  for (sig = sigtab; sig < sigtab + LENGTH (sigtab); sig++)
    printf ("%2d\t%s\n", sig->signo, sig->name);
  exit (EXIT_SUCCESS);
}

static
#ifdef __GNUC__
  __attribute__((__unused__))
#endif
  void fail (const char *where)
{
  fprintf (stderr, "Error parsing arguments: %s\n", where);
  exit (EXIT_FAILURE);
}

static int parse_number (const char *text)
{
  char *end;
  long val;

  val = strtol (text, &end, 0);
  if (val >= 0 && (int) val == val && (end == NULL || *end == 0))
    return val;

  return -1;
}

static int parse_signal (const char *text_orig)
{
  const char *text = text_orig;
  const struct signal *sig;
  int retval;

  retval = parse_number (text);
  if (retval >= 0)
    return retval;

  if (strncasecmp (text, "SIG", 3) == 0)
    text += 3;
  for (sig = sigtab; sig < sigtab + LENGTH (sigtab); sig++)
    if (strcasecmp (sig->name, text) == 0)
      return sig->signo;

  fail (text_orig);
  /* NOTREACHED */
  return -1;
}

static void help (void)
{
  fputs ("\
tgkill -h\n\
tgkill -l\n\
tgkill {-s sigspec | -n sigspec | -sigspec} pid ...\n\
", stdout);
  exit (EXIT_SUCCESS);
}

int main (int argc, char **argv)
{
  char **argp;
  int signo;

  if (argc == 2 && strcmp (argv[1], "-h") == 0)
    help ();
  if (argc == 2 && strcmp (argv[1], "-l") == 0)
    list ();

  if (argc > 3 && (strcmp (argv[1], "-s") == 0 || strcmp (argv[1], "-n") == 0))
    {
      signo = parse_signal (argv[2]);
      argp = argv + 3;
    }
  else if (argc > 2 && argv[1][0] == '-')
    {
      signo = parse_signal (argv [1] + 1);
      argp = argv + 2;
    }
  else
    fail ("<general>");

  while (argp < argv + argc)
    {
      const char *arg = *argp++;
      int pid;

      pid = parse_number (arg);
      if (pid == -1)
        fail (arg);

      if (tkill (pid, signo) != 0)
        perror (arg);
    }

  return EXIT_SUCCESS;
}