util.lsignal: Add lsignal library for catching POSIX signals

1 files changed, 387 insertions, 0 deletions

diff --git a/util-src/lsignal.c b/util-src/lsignal.c
new file mode 100644
index 00000000..158efcd6
--- /dev/null
+++ b/util-src/lsignal.c
@@ -0,0 +1,387 @@
+/*
+ * lsignal.h -- Signal Handler Library for Lua
+ *
+ * Version: 1.000
+ *
+ * Copyright (C) 2007  Patrick J. Donnelly (batrick@unm.edu)
+ *
+ * This software is distributed under the same license as Lua 5.0:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE. 
+*/
+
+#include <signal.h>
+
+#include "lua.h"
+#include "lauxlib.h"
+
+#ifndef lsig
+
+#define lsig
+
+struct lua_signal
+{
+  char *name; /* name of the signal */
+  int sig; /* the signal */
+};
+
+#endif
+
+#define LUA_SIGNAL "lua_signal"
+
+static const struct lua_signal lua_signals[] = {
+  /* ANSI C signals */
+#ifdef SIGABRT
+  {"SIGABRT", SIGABRT},
+#endif
+#ifdef SIGFPE
+  {"SIGFPE", SIGFPE},
+#endif
+#ifdef SIGILL
+  {"SIGILL", SIGILL},
+#endif
+#ifdef SIGINT
+  {"SIGINT", SIGINT},
+#endif
+#ifdef SIGSEGV
+  {"SIGSEGV", SIGSEGV},
+#endif
+#ifdef SIGTERM
+  {"SIGTERM", SIGTERM},
+#endif
+  /* posix signals */
+#ifdef SIGHUP
+  {"SIGHUP", SIGHUP},
+#endif
+#ifdef SIGQUIT
+  {"SIGQUIT", SIGQUIT},
+#endif
+#ifdef SIGTRAP
+  {"SIGTRAP", SIGTRAP},
+#endif
+#ifdef SIGKILL
+  {"SIGKILL", SIGKILL},
+#endif
+#ifdef SIGUSR1
+  {"SIGUSR1", SIGUSR1},
+#endif
+#ifdef SIGUSR2
+  {"SIGUSR2", SIGUSR2},
+#endif
+#ifdef SIGPIPE
+  {"SIGPIPE", SIGPIPE},
+#endif
+#ifdef SIGALRM
+  {"SIGALRM", SIGALRM},
+#endif
+#ifdef SIGCHLD
+  {"SIGCHLD", SIGCHLD},
+#endif
+#ifdef SIGCONT
+  {"SIGCONT", SIGCONT},
+#endif
+#ifdef SIGSTOP
+  {"SIGSTOP", SIGSTOP},
+#endif
+#ifdef SIGTTIN
+  {"SIGTTIN", SIGTTIN},
+#endif
+#ifdef SIGTTOU
+  {"SIGTTOU", SIGTTOU},
+#endif
+  /* some BSD signals */
+#ifdef SIGIOT
+  {"SIGIOT", SIGIOT},
+#endif
+#ifdef SIGBUS
+  {"SIGBUS", SIGBUS},
+#endif
+#ifdef SIGCLD
+  {"SIGCLD", SIGCLD},
+#endif
+#ifdef SIGURG
+  {"SIGURG", SIGURG},
+#endif
+#ifdef SIGXCPU
+  {"SIGXCPU", SIGXCPU},
+#endif
+#ifdef SIGXFSZ
+  {"SIGXFSZ", SIGXFSZ},
+#endif
+#ifdef SIGVTALRM
+  {"SIGVTALRM", SIGVTALRM},
+#endif
+#ifdef SIGPROF
+  {"SIGPROF", SIGPROF},
+#endif
+#ifdef SIGWINCH
+  {"SIGWINCH", SIGWINCH},
+#endif
+#ifdef SIGPOLL
+  {"SIGPOLL", SIGPOLL},
+#endif
+#ifdef SIGIO
+  {"SIGIO", SIGIO},
+#endif
+  /* add odd signals */
+#ifdef SIGSTKFLT
+  {"SIGSTKFLT", SIGSTKFLT}, /* stack fault */
+#endif
+#ifdef SIGSYS
+  {"SIGSYS", SIGSYS},
+#endif
+  {NULL, 0}
+};
+
+static int Nsig = 0;
+static lua_State *Lsig = NULL;
+static lua_Hook Hsig = NULL;
+static int Hmask = 0;
+static int Hcount = 0;
+
+static void sighook(lua_State *L, lua_Debug *ar)
+{
+  lua_pushstring(L, LUA_SIGNAL);
+  lua_gettable(L, LUA_REGISTRYINDEX);
+  lua_pushnumber(L, Nsig);
+  lua_gettable(L, -2);
+
+  lua_call(L, 0, 0);
+
+  /* set the old hook */
+  lua_sethook(L, Hsig, Hmask, Hcount);
+}
+
+static void handle(int sig)
+{
+  Hsig = lua_gethook(Lsig);
+  Hmask = lua_gethookmask(Lsig);
+  Hcount = lua_gethookcount(Lsig);
+  Nsig = sig;
+
+  lua_sethook(Lsig, sighook, LUA_MASKCALL | LUA_MASKRET | LUA_MASKCOUNT, 1);
+  /*
+  switch (sig)
+  {
+    case SIGABRT: ;
+    case SIGFPE: ;
+    case SIGILL: ;
+    case SIGINT: ;
+    case SIGSEGV: ;
+    case SIGTERM: ;
+  } */
+}
+
+/*
+ * l_signal == signal(signal [, func [, chook]])
+ *
+ * signal = signal number or string
+ * func = Lua function to call
+ * chook = catch within C functions
+ *         if caught, Lua function _must_
+ *         exit, as the stack is most likely
+ *         in an unstable state.
+*/  
+
+static int l_signal(lua_State *L)
+{
+  int args = lua_gettop(L);
+  int t, sig; /* type, signal */
+
+  /* get type of signal */
+  luaL_checkany(L, 1);
+  t = lua_type(L, 1);
+  if (t == LUA_TNUMBER)
+    sig = (int) lua_tonumber(L, 1);
+  else if (t == LUA_TSTRING)
+  {
+    lua_pushstring(L, LUA_SIGNAL);
+    lua_gettable(L, LUA_REGISTRYINDEX);
+    lua_pushvalue(L, 1);
+    lua_gettable(L, -2);
+    if (!lua_isnumber(L, -1))
+      luaL_error(L, "invalid signal string");
+    sig = (int) lua_tonumber(L, -1);
+    lua_pop(L, 1); /* get rid of number we pushed */
+  } else
+    luaL_checknumber(L, 1); /* will always error, with good error msg */
+
+  /* set handler */
+  if (args == 1 || lua_isnil(L, 2)) /* clear handler */
+  {
+    lua_pushstring(L, LUA_SIGNAL);
+    lua_gettable(L, LUA_REGISTRYINDEX);
+    lua_pushnumber(L, sig);
+    lua_gettable(L, -2); /* return old handler */
+    lua_pushnumber(L, sig);
+    lua_pushnil(L);
+    lua_settable(L, -4);
+    lua_remove(L, -2); /* remove LUA_SIGNAL table */
+    signal(sig, SIG_DFL);
+  } else
+  {
+    luaL_checktype(L, 2, LUA_TFUNCTION);
+
+    lua_pushstring(L, LUA_SIGNAL);
+    lua_gettable(L, LUA_REGISTRYINDEX);
+
+    lua_pushnumber(L, sig);
+    lua_pushvalue(L, 2);
+    lua_settable(L, -3);
+
+    /* Set the state for the handler */
+    Lsig = L;
+
+    if (lua_toboolean(L, 3)) /* c hook? */
+    {
+      if (signal(sig, handle) == SIG_ERR)
+        lua_pushboolean(L, 0);
+      else
+        lua_pushboolean(L, 1);
+    } else /* lua_hook */
+    {
+      if (signal(sig, handle) == SIG_ERR)
+        lua_pushboolean(L, 0);
+      else
+        lua_pushboolean(L, 1);
+    }
+  }
+  return 1;
+}
+
+/*
+ * l_raise == raise(signal)
+ *
+ * signal = signal number or string
+*/  
+
+static int l_raise(lua_State *L)
+{
+  /* int args = lua_gettop(L); */
+  int t = 0; /* type */
+  lua_Number ret;
+
+  luaL_checkany(L, 1);
+
+  t = lua_type(L, 1);
+  if (t == LUA_TNUMBER)
+  {
+    ret = (lua_Number) raise((int) lua_tonumber(L, 1));
+    lua_pushnumber(L, ret);
+  } else if (t == LUA_TSTRING)
+  {
+    lua_pushstring(L, LUA_SIGNAL);
+    lua_gettable(L, LUA_REGISTRYINDEX);
+    lua_pushvalue(L, 1);
+    lua_gettable(L, -2);
+    if (!lua_isnumber(L, -1))
+      luaL_error(L, "invalid signal string");
+    ret = (lua_Number) raise((int) lua_tonumber(L, -1));
+    lua_pop(L, 1); /* get rid of number we pushed */
+    lua_pushnumber(L, ret);
+  } else
+    luaL_checknumber(L, 1); /* will always error, with good error msg */
+
+  return 1;
+}
+
+#ifdef _POSIX_SOURCE
+
+/* define some posix only functions */
+
+/*
+ * l_kill == kill(pid, signal)
+ *
+ * pid = process id
+ * signal = signal number or string
+*/  
+
+static int l_kill(lua_State *L)
+{
+  int t; /* type */
+  lua_Number ret; /* return value */
+
+  luaL_checknumber(L, 1); /* must be int for pid */
+  luaL_checkany(L, 2); /* check for a second arg */
+
+  t = lua_type(L, 2);
+  if (t == LUA_TNUMBER)
+  {
+    ret = (lua_Number) kill((int) lua_tonumber(L, 1),
+        (int) lua_tonumber(L, 2));
+    lua_pushnumber(L, ret);
+  } else if (t == LUA_TSTRING)
+  {
+    lua_pushstring(L, LUA_SIGNAL);
+    lua_gettable(L, LUA_REGISTRYINDEX);
+    lua_pushvalue(L, 2);
+    lua_gettable(L, -2);
+    if (!lua_isnumber(L, -1))
+      luaL_error(L, "invalid signal string");
+    ret = (lua_Number) kill((int) lua_tonumber(L, 1),
+        (int) lua_tonumber(L, -1));
+    lua_pop(L, 1); /* get rid of number we pushed */
+    lua_pushnumber(L, ret);
+  } else
+    luaL_checknumber(L, 2); /* will always error, with good error msg */
+  return 1;
+}
+
+#endif
+
+static const struct luaL_Reg lsignal_lib[] = {
+  {"signal", l_signal},
+  {"raise", l_raise},
+#ifdef _POSIX_SOURCE
+  {"kill", l_kill},
+#endif
+  {NULL, NULL}
+};
+
+int luaopen_util_signal(lua_State *L)
+{
+  int i = 0;
+
+  /* add the library */
+  luaL_register(L, "signal", lsignal_lib);
+
+  /* push lua_signals table into the registry */
+  /* put the signals inside the library table too,
+   * they are only a reference */
+  lua_pushstring(L, LUA_SIGNAL);
+  lua_createtable(L, 0, 0);
+
+  while (lua_signals[i].name != NULL)
+  {
+    /* registry table */
+    lua_pushstring(L, lua_signals[i].name);
+    lua_pushnumber(L, lua_signals[i].sig);
+    lua_settable(L, -3);
+    /* signal table */
+    lua_pushstring(L, lua_signals[i].name);
+    lua_pushnumber(L, lua_signals[i].sig);
+    lua_settable(L, -5);
+    i++;
+  }
+
+  /* add newtable to the registry */
+  lua_settable(L, LUA_REGISTRYINDEX);
+
+  return 1;
+}