# 
# 
# add_dir "tests/spawn_pipe"
# 
# add_file "tests/spawn_pipe/__driver__.lua"
#  content [b6b2fbb790474725f0001aceabc3f2bfa00f4aa0]
# 
# add_file "tests/spawn_pipe/testhooks"
#  content [b1735be0668a2b9768f96add9dbb2eb27022f287]
# 
# patch "lua_hooks.cc"
#  from [02a923f2e6c785ccc218a67ba83acbbbc04a179b]
#    to [7455b70dc877298e9c99d421a6f6e3a219ddfb3e]
# 
# patch "luaext_platform.cc"
#  from [6976e27d72d532b83eb7ca05067e9835b2e0f582]
#    to [85950c0a7933f6df1c9261172a4df13a0b354255]
# 
# patch "platform.hh"
#  from [7224b228b7c8f0476b45ed5fb929aba4d6878fd5]
#    to [2aa9734b2d5a30bce47c8c2f12e8d6729451baf9]
# 
# patch "unix/process.cc"
#  from [d00d8b746198ce7ca79923ba000d947587b8b485]
#    to [faa15cf6776000e3dfd3ab41fc4b209daad10e87]
# 
# patch "win32/process.cc"
#  from [cc87fd97460d2c5245792aca838469129f098e6b]
#    to [35decb7bfc80bcd54893ce784c325c71c1415e3d]
# 
============================================================
--- tests/spawn_pipe/__driver__.lua	b6b2fbb790474725f0001aceabc3f2bfa00f4aa0
+++ tests/spawn_pipe/__driver__.lua	b6b2fbb790474725f0001aceabc3f2bfa00f4aa0
@@ -0,0 +1,9 @@
+
+mtn_setup()
+
+check(get("testhooks"))
+
+xfail_if(ostype == "Windows", raw_mtn("--rcfile=testhooks", "ls", "unknown"), 0, false, false)
+
+skip_if(exists("skipfile"))
+check(exists("outfile"))
============================================================
--- tests/spawn_pipe/testhooks	b1735be0668a2b9768f96add9dbb2eb27022f287
+++ tests/spawn_pipe/testhooks	b1735be0668a2b9768f96add9dbb2eb27022f287
@@ -0,0 +1,42 @@
+function ignore_file (name)
+  ok = true
+
+  mytext = "text from lua1"
+
+  result = "ok"
+
+  if ok then
+    if existsonpath("cat") == 0 then
+      procfin, procfout, pid = spawn_pipe("cat")
+      if pid == -1 then
+        result = "no pid"
+        ok = false
+      else
+        procfin:write(mytext)
+        procfin:close()
+        line, errstr = procfout:read()
+        if line == nil then
+          result = "no line"
+          ok = false
+        elseif line ~= mytext then
+          result = "Expected: " .. mytext .. "\nRead: " .. line
+          ok = false
+        end
+        procfout:close()
+        ret, pid = wait(pid)
+      end
+    else
+      result = "Lacking cat"
+      x = io.open("skipfile", "w")
+      x:close()
+    end
+  end
+  
+  if ok then
+    x = io.open("outfile", "w")
+    x:close()
+  end
+
+  ignore_file = function (name) return true end
+  return true
+end
============================================================
--- lua_hooks.cc	02a923f2e6c785ccc218a67ba83acbbbc04a179b
+++ lua_hooks.cc	7455b70dc877298e9c99d421a6f6e3a219ddfb3e
@@ -92,8 +92,10 @@ lua_hooks::lua_hooks()
   // Disable any functions we don't want. This is easiest
   // to do just by running a lua string.
   if (!run_string(st,
-                  "os.execute = nil "
-                  "io.popen = nil ",
+                  // "os.unsafeexecute = os.execute "
+                  // "io.unsafepopen = io.popen "
+                  "os.execute = function(c) error(\"os.execute disabled for security reasons.  Try spawn().\") end "
+                  "io.popen = function(c,t) error(\"io.popen disabled for security reasons.  Try spawn_pipe().\") end ",
                   string("<disabled dangerous functions>")))
     throw oops("lua error while disabling existing functions");
 }
============================================================
--- luaext_platform.cc	6976e27d72d532b83eb7ca05067e9835b2e0f582
+++ luaext_platform.cc	85950c0a7933f6df1c9261172a4df13a0b354255
@@ -78,6 +78,59 @@ LUAEXT(spawn_redirected, )
   return 1;
 }
 
+// borrowed from lua/liolib.cc
+// Note that making C functions that return FILE* in Lua is tricky
+// There is a Lua FAQ entitled:
+// "Why does my library-created file segfault on :close() but work otherwise?"
+
+#define topfile(L)	((FILE **)luaL_checkudata(L, 1, LUA_FILEHANDLE))
+
+static int io_fclose (lua_State *L) {
+  FILE **p = topfile(L);
+  int ok = (fclose(*p) == 0);
+  *p = NULL;
+  lua_pushboolean(L, ok);
+  return 1;
+}
+
+static FILE **newfile (lua_State *L) {
+  FILE **pf = (FILE **)lua_newuserdata(L, sizeof(FILE *));
+  *pf = NULL;  /* file handle is currently `closed' */
+  luaL_getmetatable(L, LUA_FILEHANDLE);
+  lua_setmetatable(L, -2);
+
+  lua_pushcfunction(L, io_fclose);
+  lua_setfield(L, LUA_ENVIRONINDEX, "__close");
+
+  return pf;
+}
+
+LUAEXT(spawn_pipe, )
+{
+  int n = lua_gettop(L);
+  char **argv = (char**)malloc((n+1)*sizeof(char*));
+  int i;
+  pid_t pid;
+  if (argv==NULL)
+    return 0;
+  if (n<1)
+    return 0;
+  for (i=0; i<n; i++) argv[i] = (char*)luaL_checkstring(L,  i+1);
+  argv[i] = NULL;
+  
+  int infd;
+  FILE **inpf = newfile(L);
+  int outfd;
+  FILE **outpf = newfile(L);
+
+  pid = process_spawn_pipe(argv, inpf, outpf);
+  free(argv);
+
+  lua_pushnumber(L, pid);
+
+  return 3;
+}
+
 LUAEXT(wait, )
 {
   pid_t pid = static_cast<pid_t>(luaL_checknumber(L, -1));
============================================================
--- platform.hh	7224b228b7c8f0476b45ed5fb929aba4d6878fd5
+++ platform.hh	2aa9734b2d5a30bce47c8c2f12e8d6729451baf9
@@ -29,6 +29,7 @@ pid_t process_spawn_redirected(char cons
                                char const * out,
                                char const * err,
                                char const * const argv[]);
+pid_t process_spawn_pipe(char const * const argv[], FILE** in, FILE** out);
 int process_wait(pid_t pid, int *res, int timeout = -1);// default infinite
 int process_kill(pid_t pid, int signal);
 int process_sleep(unsigned int seconds);
============================================================
--- unix/process.cc	d00d8b746198ce7ca79923ba000d947587b8b485
+++ unix/process.cc	faa15cf6776000e3dfd3ab41fc4b209daad10e87
@@ -163,6 +163,56 @@ pid_t process_spawn_redirected(char cons
     }
 }
 
+pid_t process_spawn_pipe(char const * const argv[], FILE** in, FILE** out)
+{
+  int infds[2];
+  int outfds[2];
+  pid_t pid;
+  
+  if (pipe(infds) < 0)
+    return -1;
+  if (pipe(outfds) < 0)
+    {
+      close(infds[0]);
+      close(infds[1]);
+      return -1;
+    }
+  
+  switch(pid = vfork())
+    {
+      case -1:
+        close(infds[0]);
+        close(infds[1]);
+        close(outfds[0]);
+        close(outfds[1]);
+        return -1;
+      case 0:
+        {
+          if (infds[0] != STDIN_FILENO)
+            {
+              dup2(infds[0], STDIN_FILENO);
+              close(infds[0]);
+            }
+          close(infds[1]);
+          if (outfds[1] != STDOUT_FILENO)
+            {
+              dup2(outfds[1], STDOUT_FILENO);
+              close(outfds[1]);
+            }
+          close(outfds[0]);
+          
+          execvp(argv[0], (char * const *)argv);
+          raise(SIGKILL);
+        }
+    }
+  close(infds[0]);
+  close(outfds[1]);
+  *in = fdopen(infds[1], "w");
+  *out = fdopen(outfds[0], "r");
+  
+  return pid;
+}
+
 int process_wait(pid_t pid, int *res, int timeout)
 {
   int status;
============================================================
--- win32/process.cc	cc87fd97460d2c5245792aca838469129f098e6b
+++ win32/process.cc	35decb7bfc80bcd54893ce784c325c71c1415e3d
@@ -228,6 +228,12 @@ pid_t process_spawn_redirected(char cons
     }
 }
 
+pid_t process_spawn_pipe(char const * const argv[], FILE** in, FILE** out)
+{
+  // XXX: not implemented on Win32 yet
+  return -1;
+}
+
 int process_wait(pid_t pid, int *res, int timeout)
 {
   HANDLE hProcess = (HANDLE)pid;