svn update: 48958 (latest:48959)

[framework/uifw/ecore.git] / src / lib / ecore / ecore_exe.c

/*
 * vim:ts=8:sw=3:sts=8:noexpandtab:cino=>5n-3f0^-2{2
 */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#if defined (__FreeBSD__) || defined (__OpenBSD__) || defined (__NetBSD__)
# include <sys/time.h>
# include <sys/resource.h>
#endif

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>

#ifdef HAVE_SYS_WAIT_H
# include <sys/wait.h>
#endif

#include "Ecore.h"
#include "ecore_private.h"


   /* FIXME: Getting respawn to work
    *
    * There is no way that we can do anything about the internal state info of
    * an external exe.  The same can be said about the state of user code.  User
    * code in this context means the code that is using ecore_exe to manage exe's
    * for it.
    *
    * Document that the exe must be respawnable, in other words, there is no
    * state that it cannot regenerate by just killing it and starting it again.
    * This includes state that the user code knows about, as the respawn is
    * transparent to that code.  On the other hand, maybe a respawn event might
    * be useful, or maybe resend the currently non existant add event.  For
    * consistancy with ecore_con, an add event is good anyway.
    *
    * The Ecore_exe structure is reused for respawning, so that the (opaque)
    * pointer held by the user remains valid.  This means that the Ecore_Exe
    * init and del functions may need to be split into two parts each to avoid
    * duplicating code - common code part, and the rest.  This implies that
    * the unchanging members mentioned next should NEVER change.
    *
    * These structure members don't need to change -
    *   __list_data       - we stay on the list
    *   ECORE_MAGIC       - this is a constant
    *   data              - passed in originally
    *   cmd               - passed in originally
    *   flags             - passed in originally
    *
    * These structure members need to change -
    *   tag               - state that must be regenerated, zap it
    *   pid               - it will be different
    *   child_fd_write    - it will be different
    *   child_fd_read     - it will be different
    *   child_fd_error    - it will be different
    *   write_fd_handler  - we cannot change the fd used by a handler, this changes coz the fd changes.
    *   read_fd_handler   - we cannot change the fd used by a handler, this changes coz the fd changes.
    *   error_fd_handler  - we cannot change the fd used by a handler, this changes coz the fd changes.
    *
    * Hmm, the read, write, and error buffers could be tricky.
    * They are not atomic, and could be in a semi complete state.
    * They fall into the "state must be regenerated" mentioned above.
    * A respawn/add event should take care of it.
    *
    * These structure members need to change -
    *   write_data_buf    - state that must be regenerated, zap it
    *   write_data_size   - state that must be regenerated, zap it
    *   write_data_offset - state that must be regenerated, zap it
    *   read_data_buf     - state that must be regenerated, zap it
    *   read_data_size    - state that must be regenerated, zap it
    *   error_data_buf    - state that must be regenerated, zap it
    *   error_data_size   - state that must be regenerated, zap it
    *   close_write       - state that must be regenerated, zap it
    *
    * There is the problem that an exe that fell over and needs respawning
    * might keep falling over, keep needing to be respawned, and tie up system
    * resources with the constant respawning.  An exponentially increasing
    * timeout (with maximum timeout) between respawns should take care of that.
    * Although this is not a "contention for a resource" problem, the exe falling
    * over may be, so a random element added to the timeout may help, and won't
    * hurt.  The user code may need to be informed that a timeout is in progress.
    */

struct _Ecore_Exe
{
   EINA_INLIST;
   ECORE_MAGIC;
   pid_t pid;
   void *data;
   char *tag, *cmd;
   Ecore_Exe_Flags  flags;
   Ecore_Fd_Handler *write_fd_handler; /* the fd_handler to handle write to child - if this was used, or NULL if not */
   Ecore_Fd_Handler *read_fd_handler; /* the fd_handler to handle read from child - if this was used, or NULL if not */
   Ecore_Fd_Handler *error_fd_handler; /* the fd_handler to handle errors from child - if this was used, or NULL if not */
   void  *write_data_buf; /* a data buffer for data to write to the child -
                                 * realloced as needed for more data and flushed when the fd handler says writes are possible
                                 */
   int write_data_size; /* the size in bytes of the data buffer */
   int write_data_offset; /* the offset in bytes in the data buffer */
   void *read_data_buf; /* data read from the child awating delivery to an event */
   int read_data_size; /* data read from child in bytes */
   void *error_data_buf; /* errors read from the child awating delivery to an event */
   int error_data_size; /* errors read from child in bytes */
   int child_fd_write;  /* fd to write TO to send data to the child */
   int child_fd_read;   /* fd to read FROM when child has sent us (the parent) data */
   int child_fd_error;  /* fd to read FROM when child has sent us (the parent) errors */
   int child_fd_write_x;        /* fd to write TO to send data to the child */
   int child_fd_read_x; /* fd to read FROM when child has sent us (the parent) data */
   int child_fd_error_x;        /* fd to read FROM when child has sent us (the parent) errors */
   Eina_Bool close_stdin : 1;

   int start_bytes, end_bytes, start_lines, end_lines; /* Number of bytes/lines to auto pipe at start/end of stdout/stderr. */

   Ecore_Timer *doomsday_clock; /* The Timer of Death.  Muahahahaha. */
   void *doomsday_clock_dead; /* data for the doomsday clock */

   void (*pre_free_cb)(void *data, const Ecore_Exe *exe);
};


/* TODO: Something to let people build a command line and does auto escaping -
 *
 * ecore_exe_snprintf()
 *
 *   OR
 *
 * cmd = ecore_exe_comand_parameter_append(cmd, "firefox");
 * cmd = ecore_exe_comand_parameter_append(cmd, "http://www.foo.com/bar.html?baz=yes");
 * each parameter appended is one argument, and it gets escaped, quoted, and
 * appended with a preceeding space.  The first is the command off course.
 */

struct _ecore_exe_dead_exe
{
   pid_t pid;
   char *cmd;
};

static inline void _ecore_exe_exec_it(const char *exe_cmd, Ecore_Exe_Flags flags);
static int _ecore_exe_data_generic_handler(void *data, Ecore_Fd_Handler *fd_handler, Ecore_Exe_Flags flags);
static int _ecore_exe_data_error_handler(void *data, Ecore_Fd_Handler *fd_handler);
static int _ecore_exe_data_read_handler(void *data, Ecore_Fd_Handler *fd_handler);
static int _ecore_exe_data_write_handler(void *data, Ecore_Fd_Handler *fd_handler);
static void _ecore_exe_flush(Ecore_Exe * exe);
static void _ecore_exe_event_exe_data_free(void *data __UNUSED__, void *ev);
static Ecore_Exe *_ecore_exe_is_it_alive(pid_t pid);
static int _ecore_exe_make_sure_its_dead(void *data);
static int _ecore_exe_make_sure_its_really_dead(void *data);
static Ecore_Exe_Event_Add *_ecore_exe_event_add_new(void);
static void _ecore_exe_event_add_free(void *data, void *ev);
static void _ecore_exe_dead_attach(Ecore_Exe *exe);

EAPI int ECORE_EXE_EVENT_ADD = 0;
EAPI int ECORE_EXE_EVENT_DEL = 0;
EAPI int ECORE_EXE_EVENT_DATA = 0;
EAPI int ECORE_EXE_EVENT_ERROR = 0;

static Ecore_Exe *exes = NULL;
static const char *shell = NULL;

/* FIXME: This errno checking stuff should be put elsewhere for everybody to use.
 * For now it lives here though, just to make testing easier.
 */
static int _ecore_exe_check_errno(int result, const char *file, int line);

#define E_IF_NO_ERRNO(result, foo, ok) \
  while (((ok) = _ecore_exe_check_errno( (result) = (foo), __FILE__, __LINE__)) == -1)   sleep(1); \
  if (ok)

#define E_NO_ERRNO(result, foo, ok) \
  while (((ok) = _ecore_exe_check_errno( (result) = (foo), __FILE__, __LINE__)) == -1)   sleep(1)

#define E_IF_NO_ERRNO_NOLOOP(result, foo, ok) \
  if (((ok) = _ecore_exe_check_errno( (result) = (foo), __FILE__, __LINE__)))

static int
_ecore_exe_check_errno(int result, const char *file, int line)
{
   int saved_errno = errno;

   if (result == -1)
     {
        perror("*** errno reports ");
/* What is currently supported -
 *
 *   pipe
 *     EFAULT  Argument is not valid.
 *     EMFILE  Too many file descriptors used by process.
 *     ENFILE  Too many open files by system.
 *   read
 *     EAGAIN  No data now, try again.
 *     EBADF   This is not an fd that can be read.
 *     EFAULT  This is not a valid buffer.
 *     EINTR   Interupted by signal, try again.
 *     EINVAL  This is not an fd that can be read.
 *     EIO     I/O error.
 *     EISDIR  This is a directory, and cannot be read.
 *     others  Depending on what sort of thing we are reading from.
 *   close
 *     EBADF   This is not an fd that can be closed.
 *     EINTR   Interupted by signal, try again.
 *     EIO     I/O error.
 *   dup2
 *     EBADF   This is not an fd that can be dup2'ed.
 *     EBUSY   Race condition between open() and dup()
 *     EINTR   Interupted by signal, try again.
 *     EMFILE  Too many file descriptors used by process.
 *   fcntl
 *     EACCES, EAGAIN  Locked or mapped by something else, try again later.
 *     EBADF   This is not an fd that can be fcntl'ed.
 *     EDEADLK This will cause a deadlock.
 *     EFAULT  This is not a valid lock.
 *     EINTR   Interupted by signal, try again.
 *     EINVAL  This is not a valid arg.
 *     EMFILE  Too many file descriptors used by process.
 *     ENOLCK  Problem getting a lock.
 *     EPERM   Not allowed to do that.
 *   fsync
 *     EBADF   This is not an fd that is open for writing.
 *     EINVAL, EROFS  This is not an fd that can be fsynced.
 *     EIO     I/O error.
 *
 * How to use it -
 *    int ok = 0;
 *    int result;
 *
 *    E_IF_NO_ERRNO(result, foo(bar), ok)
 *      {
 *         E_IF_NO_ERRNO_NOLOOP(result, foo(bar), ok)
 *            {
 *            }
 *      }
 *
 *   if (!ok)
 *     {
 *        // Something failed, cleanup.
 *     }
 */
        switch (saved_errno)
          {
           case EACCES:
           case EAGAIN:
           case EINTR:
               { /* Not now, try later. */
                  ERR("*** Must try again in %s @%u.", file, line);
                  result = -1;
                  break;
               }
           case EMFILE:
           case ENFILE:
           case ENOLCK:
               { /* Low on resources. */
                  ERR("*** Low on resources in %s @%u.", file,
                      line);
                  result = 0;
                  break;
               }
           case EIO:
               { /* I/O error. */
                  ERR("*** I/O error in %s @%u.", file, line);
                  result = 0;
                  break;
               }
           case EFAULT:
           case EBADF:
           case EINVAL:
           case EROFS:
           case EISDIR:
           case EDEADLK:
           case EPERM:
           case EBUSY:
               { /* Programmer fucked up. */
                  ERR("*** NAUGHTY PROGRAMMER!!!\n"
                      "*** SPANK SPANK SPANK!!!\n"
                      "*** Now go fix your code in %s @%u. Tut tut tut!",
                      file, line);
                  result = 0;
                  break;
               }
           default:
               { /* Unsupported errno code, please add this one. */
                  ERR("*** NAUGHTY PROGRAMMER!!!\n"
                      "*** SPANK SPANK SPANK!!!\n"
                      "*** Unsupported errno code %d, please add this one.\n"
                      "*** Now go fix your code in %s @%u, from %s @%u. Tut tut tut!",
                      saved_errno, __FILE__, __LINE__, file, line);
                  result = 0;
                  break;
               }
          }
     }
   else /* Everything is fine. */
     result = 1;

   errno = saved_errno;
   return result;
}

/**
 * @defgroup Ecore_Exe_Basic_Group Process Spawning Functions
 *
 * Functions that deal with spawned processes.
 */

static int run_pri = ECORE_EXE_PRIORITY_INHERIT;

/**
 * Sets the priority at which to launch processes
 *
 * This sets the priority of processes run by ecore_exe_run() and
 * ecore_exe_pipe_run().
 * @li On Windows, the child process is created by default with the
 * #ECORE_EXE_WIN32_PRIORITY_NORMAL priority, unless the calling
 * process is in #ECORE_EXE_WIN32_PRIORITY_IDLE or
 * #ECORE_EXE_WIN32_PRIORITY_BELOW_NORMAL priority. In that case, the
 * child process inherits this priority.
 * @li On other platforms, if set to #ECORE_EXE_PRIORITY_INHERIT child
 * processes inherits the priority of their parent. This is the default.
 *
 * @param   pri value a Ecore_Exe_Win32_Priority value on Windows, -20
 * to 19 or ECORE_EXE_PRIORITY_INHERIT on other OS.
 * @ingroup Ecore_Exe_Basic_Group
 */
EAPI void
ecore_exe_run_priority_set(int pri)
{
   run_pri = pri;
}

/**
 * Gets the priority at which to launch processes
 *
 * This gets ths priority of launched processes. See
 * ecore_exe_run_priority_set() for details. This just returns the value set
 * by this call.
 *
 * @return the value set by ecore_exe_run_priority_set()
 * @ingroup Ecore_Exe_Basic_Group
 */
EAPI int
ecore_exe_run_priority_get(void)
{
   return run_pri;
}

/**
 * Spawns a child process.
 *
 * This is now just a thin wrapper around ecore_exe_pipe_run()
 *
 * @param   exe_cmd The command to run with @c /bin/sh.
 * @param   data    Data to attach to the returned process handle.
 * @return  A process handle to the spawned process.
 * @ingroup Ecore_Exe_Basic_Group
 */
EAPI Ecore_Exe *
ecore_exe_run(const char *exe_cmd, const void *data)
{
/* I'm just being paranoid again, leaving in the original code in case there is a problem. */
#if 0
   Ecore_Exe *exe;
   pid_t pid;

   if (!exe_cmd)
      return NULL;
   pid = fork();
   if (pid)
     {
        exe = calloc(1, sizeof(Ecore_Exe));
        if (!exe)
          {
             kill(pid, SIGKILL);
             return NULL;
          }
        ECORE_MAGIC_SET(exe, ECORE_MAGIC_EXE);
        exe->pid = pid;
        exe->data = (void *)data;
        exe->cmd = strdup(exe_cmd);
        exes = _ecore_list2_append(exes, exe);
        return exe;
     }
   _ecore_exe_exec_it(exe_cmd, 0);
   exit(127);
   return NULL;
#else
   return ecore_exe_pipe_run(exe_cmd, 0, data);
#endif
}

/**
 * Spawns a child process with its stdin/out available for communication.
 *
 * This function forks and runs the given command using @c /bin/sh.
 *
 * Note that the process handle is only valid until a child process
 * terminated event is received.  After all handlers for the child process
 * terminated event have been called, the handle will be freed by Ecore.
 *
 * This function does the same thing as ecore_exe_run(), but also makes the
 * standard in and/or out as well as stderr from the child process available
 * for reading or writing.  To write use ecore_exe_send().  To read listen to
 * ECORE_EXE_EVENT_DATA or ECORE_EXE_EVENT_ERROR events (set up handlers).
 * Ecore may buffer read and error data until a newline character if asked
 * for with the @p flags.  All data will be included in the events (newlines
 * will be replaced with NULLS if line buffered).  ECORE_EXE_EVENT_DATA events
 * will only happen if the process is run with ECORE_EXE_PIPE_READ enabled
 * in the flags.  The same with the error version.  Writing will only be
 * allowed with ECORE_EXE_PIPE_WRITE enabled in the flags.
 *
 * @param   exe_cmd The command to run with @c /bin/sh.
 * @param   flags   The flag parameters for how to deal with inter-process I/O
 * @param   data    Data to attach to the returned process handle.
 * @return  A process handle to the spawned process.
 * @ingroup Ecore_Exe_Basic_Group
 */
EAPI Ecore_Exe *
ecore_exe_pipe_run(const char *exe_cmd, Ecore_Exe_Flags flags, const void *data)
{
   Ecore_Exe *exe = NULL;
   int statusPipe[2] = { -1, -1 };
   int errorPipe[2] = { -1, -1 };
   int readPipe[2] = { -1, -1 };
   int writePipe[2] = { -1, -1 };
   int n = 0;
   int ok = 1;
   int result;

   if (!exe_cmd) return NULL;
   exe = calloc(1, sizeof(Ecore_Exe));
   if (exe == NULL) return NULL;

   if ((flags & ECORE_EXE_PIPE_AUTO) && (!(flags & ECORE_EXE_PIPE_ERROR))
       && (!(flags & ECORE_EXE_PIPE_READ)))
     /* We need something to auto pipe. */
     flags |= ECORE_EXE_PIPE_READ | ECORE_EXE_PIPE_ERROR;

   exe->child_fd_error = -1;
   exe->child_fd_read = -1;
   exe->child_fd_write = -1;
   exe->child_fd_error_x = -1;
   exe->child_fd_read_x = -1;
   exe->child_fd_write_x = -1;

   /*  Create some pipes. */
   if (ok)
     {
        E_IF_NO_ERRNO_NOLOOP(result, pipe(statusPipe), ok)
          {
          }
     }
   if (ok && (flags & ECORE_EXE_PIPE_ERROR))
     {
        E_IF_NO_ERRNO_NOLOOP(result, pipe(errorPipe), ok)
          {
             exe->child_fd_error = errorPipe[0];
             exe->child_fd_error_x = errorPipe[1];
          }
     }
   if (ok && (flags & ECORE_EXE_PIPE_READ))
     {
        E_IF_NO_ERRNO_NOLOOP(result, pipe(readPipe), ok)
          {
             exe->child_fd_read = readPipe[0];
             exe->child_fd_read_x = readPipe[1];
          }
     }
   if (ok && (flags & ECORE_EXE_PIPE_WRITE))
     {
        E_IF_NO_ERRNO_NOLOOP(result, pipe(writePipe), ok)
          {
             exe->child_fd_write = writePipe[1];
             exe->child_fd_write_x = writePipe[0];
          }
     }
   if (ok)
     {
        pid_t pid = 0;
        volatile int vfork_exec_errno = 0;

        /* FIXME: I should double check this.  After a quick look around, this is already done, but via a more modern method. */
        /* signal(SIGPIPE, SIG_IGN);    We only want EPIPE on errors */
        pid = fork();

        if (pid == -1)
          {
             ERR("Failed to fork process");
             pid = 0;
          }
        else if (pid == 0)      /* child */
          {
             if (run_pri != ECORE_EXE_PRIORITY_INHERIT)
               {
                  if ((run_pri >= -20) && (run_pri <= 19))
                    setpriority(PRIO_PROCESS, 0, run_pri);
               }
             /* dup2 STDERR, STDIN, and STDOUT.  dup2() allegedly closes the
              * second pipe if it's open. On the other hand, there was the
              * Great FD Leak Scare of '06, so let's be paranoid. */
             if (ok && (flags & ECORE_EXE_PIPE_ERROR))
               {
                  E_NO_ERRNO(result, close(STDERR_FILENO), ok);
                  E_NO_ERRNO(result, dup2(errorPipe[1], STDERR_FILENO), ok);
               }
             if (ok && (flags & ECORE_EXE_PIPE_READ))
               {
                  E_NO_ERRNO(result, close(STDOUT_FILENO), ok);
                  E_NO_ERRNO(result, dup2(readPipe[1], STDOUT_FILENO), ok);
               }
             if (ok && (flags & ECORE_EXE_PIPE_WRITE))
               {
                  E_NO_ERRNO(result, close(STDIN_FILENO), ok);
                  E_NO_ERRNO(result, dup2(writePipe[0], STDIN_FILENO), ok);
               }

             if (ok)
               {
                  /* Setup the status pipe. */
                  E_NO_ERRNO(result, close(statusPipe[0]), ok);
                  E_IF_NO_ERRNO(result, fcntl(statusPipe[1], F_SETFD, FD_CLOEXEC), ok)  /* close on exec shows sucess */
                    {
                       /* Run the actual command. */
                       _ecore_exe_exec_it(exe_cmd, flags); /* no return */
                    }
               }

             /* Something went 'orribly wrong. */
             vfork_exec_errno = errno;

             /* Close the pipes. */
             if (flags & ECORE_EXE_PIPE_ERROR)
               E_NO_ERRNO(result, close(errorPipe[1]), ok);
             if (flags & ECORE_EXE_PIPE_READ)
               E_NO_ERRNO(result, close(readPipe[1]), ok);
             if (flags & ECORE_EXE_PIPE_WRITE)
               E_NO_ERRNO(result, close(writePipe[0]), ok);
             E_NO_ERRNO(result, close(statusPipe[1]), ok);

             _exit(-1);
          }
        else /* parent */
          {
             /* Close the unused pipes. */
             E_NO_ERRNO(result, close(statusPipe[1]), ok);

             /* FIXME: after having a good look at the current e fd
              * handling, investigate fcntl(dataPipe[x], F_SETSIG, ...) */
             /* FIXME: above F_SETSIG etc. - this is async SIGIO based IO
              * which is also linux specific so we probably don't want to
              * do this as long as select() is working fine. the only time
              * we really want to think of SIGIO async IO is when it all
              * actually works basically everywhere and we can turn all
              * IO into DMA async activities (i.e. you do a read() then
              * the read is complete not on return but when you get a
              * SIGIO - the read() just starts the transfer and it is
              * completed in the background by DMA (or whatever mechanism
              * the kernel choses)) */

             /* Wait for it to start executing. */
             /* FIXME: this doesn't seem very nice - we sit and block
              * waiting on a child process... even though it's just
              * the segment between the fork() and the exec) it just feels
              * wrong */
             for (;;)
               {
                  char buf;

                  E_NO_ERRNO(result, read(statusPipe[0], &buf, 1), ok);
                  if (result == 0)
                    {
                       if (vfork_exec_errno != 0)
                         {
                            n = vfork_exec_errno;
                            ERR("Could not start \"%s\"", exe_cmd);
                            pid = 0;
                         }
                       break;
                    }
               }

             /* Close the status pipe. */
             E_NO_ERRNO(result, close(statusPipe[0]), ok);
          }

        if (pid)
          {
             /* Setup the exe structure. */
             ECORE_MAGIC_SET(exe, ECORE_MAGIC_EXE);
             exe->start_bytes = -1;
             exe->end_bytes = -1;
             exe->start_lines = -1;
             exe->end_lines = -1;
             exe->pid = pid;
             exe->flags = flags;
             exe->data = (void *)data;
             if ((exe->cmd = strdup(exe_cmd)))
               {
                  if (flags & ECORE_EXE_PIPE_ERROR)
                    { /* Setup the error stuff. */
                       E_IF_NO_ERRNO(result,
                                     fcntl(exe->child_fd_error, F_SETFL,
                                           O_NONBLOCK), ok) {}
                       E_IF_NO_ERRNO(result,
                                     fcntl(exe->child_fd_error, F_SETFD,
                                           FD_CLOEXEC), ok) {}
                       E_IF_NO_ERRNO(result,
                                     fcntl(exe->child_fd_error_x, F_SETFD,
                                           FD_CLOEXEC), ok) {}
                       {
                          exe->error_fd_handler =
                             ecore_main_fd_handler_add(exe->child_fd_error,
                                                       ECORE_FD_READ,
                                                       _ecore_exe_data_error_handler,
                                                       exe, NULL, NULL);
                          if (exe->error_fd_handler == NULL)
                             ok = 0;
                       }
                    }
                  if (ok && (flags & ECORE_EXE_PIPE_READ))
                    { /* Setup the read stuff. */
                       E_IF_NO_ERRNO(result,
                                     fcntl(exe->child_fd_read, F_SETFL,
                                           O_NONBLOCK), ok) {}
                       E_IF_NO_ERRNO(result,
                                     fcntl(exe->child_fd_read, F_SETFD,
                                           FD_CLOEXEC), ok) {}
                       E_IF_NO_ERRNO(result,
                                     fcntl(exe->child_fd_read_x, F_SETFD,
                                           FD_CLOEXEC), ok) {}
                       {
                          exe->read_fd_handler =
                             ecore_main_fd_handler_add(exe->child_fd_read,
                                                       ECORE_FD_READ,
                                                       _ecore_exe_data_read_handler,
                                                       exe, NULL, NULL);
                          if (exe->read_fd_handler == NULL)
                             ok = 0;
                       }
                    }
                  if (ok && (flags & ECORE_EXE_PIPE_WRITE))
                    {           /* Setup the write stuff. */
                       E_IF_NO_ERRNO(result,
                                     fcntl(exe->child_fd_write, F_SETFL,
                                           O_NONBLOCK), ok) {}
                       E_IF_NO_ERRNO(result,
                                     fcntl(exe->child_fd_write, F_SETFD,
                                           FD_CLOEXEC), ok) {}
                       E_IF_NO_ERRNO(result,
                                     fcntl(exe->child_fd_write_x, F_SETFD,
                                           FD_CLOEXEC), ok) {}
                       {
                          exe->write_fd_handler =
                             ecore_main_fd_handler_add(exe->child_fd_write,
                                                       ECORE_FD_WRITE,
                                                       _ecore_exe_data_write_handler,
                                                       exe, NULL, NULL);
                          if (exe->write_fd_handler)
                             ecore_main_fd_handler_active_set(exe->write_fd_handler, 0);        /* Nothing to write to start with. */
                          else
                             ok = 0;
                       }
                    }

                  exes = (Ecore_Exe *) eina_inlist_append(EINA_INLIST_GET(exes), EINA_INLIST_GET(exe));
                  n = 0;
               }
             else
               ok = 0;
          }
        else
          ok = 0;
     }

   if (!ok)
     { /* Something went wrong, so pull down everything. */
        if (exe->pid) ecore_exe_terminate(exe);
        IF_FN_DEL(ecore_exe_free, exe);
     }
   else
     {
        Ecore_Exe_Event_Add *e;

        e = _ecore_exe_event_add_new();
        e->exe = exe;
        if (e) /* Send the event. */
          ecore_event_add(ECORE_EXE_EVENT_ADD, e,
                          _ecore_exe_event_add_free, NULL);
        /* INF("Running as %d for %s.\n", exe->pid, exe->cmd); */
     }

   errno = n;
   return exe;
}

/**
 * Defines a function to be called before really freeing the handle data.
 *
 * This might be useful for language bindings such as Python and Perl
 * that need to deallocate wrappers associated with this handle.
 *
 * This handle should never be modified by this call. It should be
 * considered informative only. All getters are valid when the given
 * function is called back.
 *
 * @param exe The child process to attach the pre_free function.
 * @param func The function to call before @a exe is freed.
 */
EAPI void
ecore_exe_callback_pre_free_set(Ecore_Exe *exe, void (*func)(void *data, const Ecore_Exe *exe))
{
   if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
     {
        ECORE_MAGIC_FAIL(exe, ECORE_MAGIC_EXE,
                         "ecore_exe_callback_pre_free_set");
        return;
     }
   exe->pre_free_cb = func;
}

/**
 * Sends data to the given child process which it recieves on stdin.
 *
 * This function writes to a child processes standard in, with unlimited
 * buffering. This call will never block. It may fail if the system runs out
 * of memory.
 *
 * @param exe  The child process to send to
 * @param data The data to send
 * @param size The size of the data to send, in bytes
 * @return EINA_TRUE if successful, EINA_FALSE on failure.
 * @ingroup Ecore_Exe_Basic_Group
 */
EAPI Eina_Bool
ecore_exe_send(Ecore_Exe * exe, const void *data, int size)
{
   void *buf;

   if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
     {
        ECORE_MAGIC_FAIL(exe, ECORE_MAGIC_EXE, "ecore_exe_send");
        return 0;
     }

   if (exe->close_stdin)
     {
        ERR("Ecore_Exe %p stdin is closed! Cannot send %d bytes from %p",
            exe, size, data);
        return 0;
     }

   if (exe->child_fd_write == -1)
     {
        ERR("Ecore_Exe %p created without ECORE_EXE_PIPE_WRITE! "
            "Cannot send %d bytes from %p", exe, size, data);
        return 0;
     }

   buf = realloc(exe->write_data_buf, exe->write_data_size + size);
   if (buf == NULL) return 0;

   exe->write_data_buf = buf;
   memcpy((char *)exe->write_data_buf + exe->write_data_size, data, size);
   exe->write_data_size += size;

   if (exe->write_fd_handler)
      ecore_main_fd_handler_active_set(exe->write_fd_handler, ECORE_FD_WRITE);

   return 1;
}

/**
 * The stdin of the given child process will close when the write buffer is empty.
 *
 * @param exe  The child process
 * @ingroup Ecore_Exe_Basic_Group
 */
EAPI void
ecore_exe_close_stdin(Ecore_Exe *exe)
{
   if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
     {
        ECORE_MAGIC_FAIL(exe, ECORE_MAGIC_EXE, "ecore_exe_close_stdin");
        return;
     }
   exe->close_stdin = 1;
}

/**
 * Sets the auto pipe limits for the given process handle. On Windows
 * this function does nothing.
 *
 * @param   exe The given process handle.
 * @param   start_bytes limit of bytes at start of output to buffer.
 * @param   end_bytes limit of bytes at end of output to buffer.
 * @param   start_lines limit of lines at start of output to buffer.
 * @param   end_lines limit of lines at end of output to buffer.
 * @ingroup Ecore_Exe_Basic_Group
 */
EAPI void
ecore_exe_auto_limits_set(Ecore_Exe *exe, int start_bytes, int end_bytes, int start_lines, int end_lines)
{
   if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
     {
        ECORE_MAGIC_FAIL(exe, ECORE_MAGIC_EXE, "ecore_exe_auto_limits_set");
        return;
     }
   /* FIXME: sanitize the input. */
   exe->start_bytes = start_bytes;
   exe->end_bytes = end_bytes;
   exe->start_lines = start_lines;
   exe->end_lines = end_lines;

   /* FIXME: get this can of worms working.
    *
    * capture stderr & stdout internally
    *
    * raster and onefang keep moving the goal posts on this one.  It started out as
    * "show users the error output if an exe fails" and is rapidly approaching
    * "alternative method of getting the data, poll vs event driven".  Some serious
    * thinking needs to be applied to this.  Do we really want to go that far?  If
    * so, we should change the names.  The basic design will probably remain the
    * same which ever way we go.  The constant goal post moving is probably due to
    * generic design methods leading to feature creep as we inspired each other to
    * more generic designs.  It does seem like the closer we get to poll driven,
    * the more issues and corner cases there are.
    *
    * Instead of doing the usual register an event handler thing, we are ecore_exe,
    * we can take some short cuts.  Don't send the events, just leave the exe buffers
    * as is until the user asks for them, then return the event.
    *
    * start = 0,  end = 0;   clogged arteries get flushed, everything is ignored.
    * start = -1, end = -1;  clogged arteries get transferred to internal buffers.  Actually, either == -1 means buffer everything.
    * start = X,  end = 0;   buffer first X out of clogged arteries, flush and ignore rest.
    * start = 0,  end = X;   circular buffer X
    * start = X,  end = Y;   buffer first X out of clogged arteries, circular buffer Y from beginning.
    *
    * bytes vs lines, which ever one reaches the limit first.
    * Before we go beyond the start+end limit, leave the end buffer empty, and store both in the start buffer, coz they overlap.
    * After we pass the the start+end limit, insert "\n...\n" at the end of the start buffer, copy the rest to the end buffer, then store in the end buffer.
    *
    * Other issues -
    * Spank programmer for polling data if polling is not turned on.
    * Spank programmer for setting up event callbacks if polling is turned on.
    * Spank programmer for freeing the event data if it came from the event system, as that autofrees.
    * Spank the programmer if they try to set the limits bigger than what has been gathered & ignored already, coz they just lost data.
    * Spank onefang and raster for opening this can of worms.
    * Should we have seperate out/err limits?
    * Should we remove from the internal buffer the data that was delivered already?
    * If so, what to do about limits, start, and end?  They could loose their meaning.
    */
}

/**
 * Gets the auto pipe data for the given process handle
 *
 * @param   exe The given process handle.
 * @param   flags   Is this a ECORE_EXE_PIPE_READ or ECORE_EXE_PIPE_ERROR?
 * @ingroup Ecore_Exe_Basic_Group
 */
EAPI Ecore_Exe_Event_Data *
ecore_exe_event_data_get(Ecore_Exe *exe, Ecore_Exe_Flags flags)
{
   Ecore_Exe_Event_Data *e = NULL;
   int is_buffered = 0;
   unsigned char *inbuf;
   int inbuf_num;

   if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
     {
        ECORE_MAGIC_FAIL(exe, ECORE_MAGIC_EXE, "ecore_exe_event_data_get");
        return NULL;
     }

   /* Sort out what sort of event we are. */
   if (flags & ECORE_EXE_PIPE_READ)
     {
        flags = ECORE_EXE_PIPE_READ;
        if (exe->flags & ECORE_EXE_PIPE_READ_LINE_BUFFERED)
           is_buffered = 1;
     }
   else
     {
        flags = ECORE_EXE_PIPE_ERROR;
        if (exe->flags & ECORE_EXE_PIPE_ERROR_LINE_BUFFERED)
           is_buffered = 1;
     }

   /* Get the data. */
   if (flags & ECORE_EXE_PIPE_READ)
     {
        inbuf = exe->read_data_buf;
        inbuf_num = exe->read_data_size;
        exe->read_data_buf = NULL;
        exe->read_data_size = 0;
     }
   else
     {
        inbuf = exe->error_data_buf;
        inbuf_num = exe->error_data_size;
        exe->error_data_buf = NULL;
        exe->error_data_size = 0;
     }

   e = calloc(1, sizeof(Ecore_Exe_Event_Data));
   if (e)
     {
        e->exe = exe;
        e->data = inbuf;
        e->size = inbuf_num;

        if (is_buffered)
          {                     /* Deal with line buffering. */
             int max = 0;
             int count = 0;
             int i;
             int last = 0;
             char *c;

             c = (char *)inbuf;
             for (i = 0; i < inbuf_num; i++)    /* Find the lines. */
               {
                  if (inbuf[i] == '\n')
                    {
                       if (count >= max)
                         {
                            /* In testing, the lines seem to arrive in batches of 500 to 1000 lines at most, roughly speaking. */
                            max += 10;  /* FIXME: Maybe keep track of the largest number of lines ever sent, and add half that many instead of 10. */
                            e->lines = realloc(e->lines, sizeof(Ecore_Exe_Event_Data_Line) * (max + 1));        /* Allow room for the NULL termination. */
                         }
                       /* raster said to leave the line endings as line endings, however -
                        * This is line buffered mode, we are not dealing with binary here, but lines.
                        * If we are not dealing with binary, we must be dealing with ASCII, unicode, or some other text format.
                        * Thus the user is most likely gonna deal with this text as strings.
                        * Thus the user is most likely gonna pass this data to str functions.
                        * rasters way - the endings are always gonna be '\n';  onefangs way - they will always be '\0'
                        * We are handing them the string length as a convenience.
                        * Thus if they really want it in raw format, they can e->lines[i].line[e->lines[i].size - 1] = '\n'; easily enough.
                        * In the default case, we can do this conversion quicker than the user can, as we already have the index and pointer.
                        * Let's make it easy on them to use these as standard C strings.
                        *
                        * onefang is proud to announce that he has just set a new personal record for the
                        * most over documentation of a simple assignment statement.  B-)
                        */
                       inbuf[i] = '\0';
                       e->lines[count].line = c;
                       e->lines[count].size = i - last;
                       last = i + 1;
                       c = (char *)&inbuf[last];
                       count++;
                    }
               }
             if (count == 0)    /* No lines to send, cancel the event. */
               {
                  _ecore_exe_event_exe_data_free(NULL, e);
                  e = NULL;
               }
             else               /* NULL terminate the array, so that people know where the end is. */
               {
                  e->lines[count].line = NULL;
                  e->lines[count].size = 0;
               }
             if (i > last)      /* Partial line left over, save it for next time. */
               {
                  if (e) e->size = last;
                  if (flags & ECORE_EXE_PIPE_READ)
                    {
                       exe->read_data_size = i - last;
                       exe->read_data_buf = malloc(exe->read_data_size);
                       memcpy(exe->read_data_buf, c, exe->read_data_size);
                    }
                  else
                    {
                       exe->error_data_size = i - last;
                       exe->error_data_buf = malloc(exe->error_data_size);
                       memcpy(exe->error_data_buf, c, exe->error_data_size);
                    }
               }
          }
     }

   return e;
}

/**
 * Sets the string tag for the given process handle
 *
 * @param   exe The given process handle.
 * @param   tag The string tag to set on the process handle.
 * @ingroup Ecore_Exe_Basic_Group
 */
EAPI void
ecore_exe_tag_set(Ecore_Exe *exe, const char *tag)
{
   if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
     {
        ECORE_MAGIC_FAIL(exe, ECORE_MAGIC_EXE, "ecore_exe_tag_set");
        return;
     }
   IF_FREE(exe->tag);
   if (tag)
      exe->tag = strdup(tag);
   else
      exe->tag = NULL;
}

/**
 * Retrieves the tag attached to the given process handle. There is no need to
 * free it as it just returns the internal pointer value. This value is only
 * valid as long as the @p exe is valid or until the tag is set to something
 * else on this @p exe.
 *
 * @param   exe The given process handle.
 * @return The string attached to @p exe. It is a handle to existing
 *         internal string and should not be modified, use
 *         ecore_exe_tag_set() to change it. It might be @c NULL.
 * @ingroup Ecore_Exe_Basic_Group
 */
EAPI const char *
ecore_exe_tag_get(const Ecore_Exe *exe)
{
   if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
     {
        ECORE_MAGIC_FAIL(exe, ECORE_MAGIC_EXE, "ecore_exe_tag_get");
        return NULL;
     }
   return exe->tag;
}

/**
 * Frees the given process handle.
 *
 * Note that the process that the handle represents is unaffected by this
 * function.
 *
 * @param   exe The given process handle.
 * @return  The data attached to the handle when @ref ecore_exe_run was
 *          called.
 * @ingroup Ecore_Exe_Basic_Group
 */
EAPI void *
ecore_exe_free(Ecore_Exe *exe)
{
   void *data;
   int ok = 0;
   int result;

   if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
     {
        ECORE_MAGIC_FAIL(exe, ECORE_MAGIC_EXE, "ecore_exe_free");
        return NULL;
     }

   data = exe->data;

   if (exe->pre_free_cb)
     exe->pre_free_cb(data, exe);

   if (exe->doomsday_clock)
     {
        struct _ecore_exe_dead_exe *dead;

        ecore_timer_del(exe->doomsday_clock);
        exe->doomsday_clock = NULL;
        dead = exe->doomsday_clock_dead;
        if (dead)
          {
             IF_FREE(dead->cmd);
             free(dead);
             exe->doomsday_clock_dead = NULL;
          }
     }
   IF_FN_DEL(ecore_main_fd_handler_del, exe->write_fd_handler);
   IF_FN_DEL(ecore_main_fd_handler_del, exe->read_fd_handler);
   IF_FN_DEL(ecore_main_fd_handler_del, exe->error_fd_handler);
   if (exe->child_fd_write_x != -1)
      E_NO_ERRNO(result, close(exe->child_fd_write_x), ok);
   if (exe->child_fd_read_x != -1)
      E_NO_ERRNO(result, close(exe->child_fd_read_x), ok);
   if (exe->child_fd_error_x != -1)
      E_NO_ERRNO(result, close(exe->child_fd_error_x), ok);
   if (exe->child_fd_write != -1)
      E_NO_ERRNO(result, close(exe->child_fd_write), ok);
   if (exe->child_fd_read != -1)
      E_NO_ERRNO(result, close(exe->child_fd_read), ok);
   if (exe->child_fd_error != -1)
      E_NO_ERRNO(result, close(exe->child_fd_error), ok);
   IF_FREE(exe->write_data_buf);
   IF_FREE(exe->read_data_buf);
   IF_FREE(exe->error_data_buf);
   IF_FREE(exe->cmd);

   exes = (Ecore_Exe *) eina_inlist_remove(EINA_INLIST_GET(exes), EINA_INLIST_GET(exe));
   ECORE_MAGIC_SET(exe, ECORE_MAGIC_NONE);
   IF_FREE(exe->tag);
   free(exe);
   return data;
}

/**
 * Frees the given event data.
 *
 * @param   e The given event data.
 * @ingroup Ecore_Exe_Basic_Group
 */
EAPI void
ecore_exe_event_data_free(Ecore_Exe_Event_Data *e)
{
   if (!e) return;
   IF_FREE(e->lines);
   IF_FREE(e->data);
   free(e);
}

/**
 * Retrieves the process ID of the given spawned process.
 * @param   exe Handle to the given spawned process.
 * @return  The process ID on success.  @c -1 otherwise.
 * @ingroup Ecore_Exe_Basic_Group
 */
EAPI pid_t
ecore_exe_pid_get(const Ecore_Exe *exe)
{
   if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
     {
        ECORE_MAGIC_FAIL(exe, ECORE_MAGIC_EXE, "ecore_exe_pid_get");
        return -1;
     }
   return exe->pid;
}

/**
 * Retrieves the command of the given spawned process.
 * @param   exe Handle to the given spawned process.
 * @return The command on success.  NULL otherwise. This string is the
 *         pointer to the internal value and must not be modified in
 *         any way.
 * @ingroup Ecore_Exe_Basic_Group
 */
EAPI const char *
ecore_exe_cmd_get(const Ecore_Exe *exe)
{
   if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
     {
        ECORE_MAGIC_FAIL(exe, ECORE_MAGIC_EXE, "ecore_exe_cmd_get");
        return NULL;
     }
   return exe->cmd;
}

/**
 * Retrieves the data attached to the given process handle.
 * @param   exe The given process handle.
 * @return The data pointer attached to @p exe Given to
 *         ecore_exe_run() or ecore_exe_pipe_run()
 * @ingroup Ecore_Exe_Basic_Group
 */
EAPI void *
ecore_exe_data_get(const Ecore_Exe *exe)
{
   if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
     {
        ECORE_MAGIC_FAIL(exe, ECORE_MAGIC_EXE, "ecore_exe_data_get");
        return NULL;
     }
   return exe->data;
}

/**
 * Retrieves the flags attached to the given process handle.
 * @param   exe The given process handle.
 * @return  The flags attached to @p exe.
 * @ingroup Ecore_Exe_Basic_Group
 */
EAPI Ecore_Exe_Flags
ecore_exe_flags_get(const Ecore_Exe *exe)
{
   if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
     {
        ECORE_MAGIC_FAIL(exe, ECORE_MAGIC_EXE, "ecore_exe_data_get");
        return 0;
     }
   return exe->flags;
}

/**
 * @defgroup Ecore_Exe_Signal_Group Spawned Process Signal Functions
 *
 * Functions that send signals to spawned processes.
 */

/**
 * Pauses the given process by sending it a @c SIGSTOP signal.
 * @param   exe Process handle to the given process.
 * @ingroup Ecore_Exe_Signal_Group
 */
EAPI void
ecore_exe_pause(Ecore_Exe *exe)
{
   if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
     {
        ECORE_MAGIC_FAIL(exe, ECORE_MAGIC_EXE, "ecore_exe_pause");
        return;
     }
   kill(exe->pid, SIGSTOP);
}

/**
 * Continues the given paused process by sending it a @c SIGCONT signal.
 * @param   exe Process handle to the given process.
 * @ingroup Ecore_Exe_Signal_Group
 */
EAPI void
ecore_exe_continue(Ecore_Exe *exe)
{
   if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
     {
        ECORE_MAGIC_FAIL(exe, ECORE_MAGIC_EXE, "ecore_exe_continue");
        return;
     }
   kill(exe->pid, SIGCONT);
}

/**
 * Sends the given spawned process a interrupt (@c SIGINT) signal.
 * @param   exe Process handle to the given process.
 * @ingroup Ecore_Exe_Signal_Group
 */
EAPI void
ecore_exe_interrupt(Ecore_Exe *exe)
{
   if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
     {
        ECORE_MAGIC_FAIL(exe, ECORE_MAGIC_EXE, "ecore_exe_interrupt");
        return;
     }
   _ecore_exe_dead_attach(exe);
   kill(exe->pid, SIGINT);
}

/**
 * Sends the given spawned process a quit (@c SIGQUIT) signal.
 * @param   exe Process handle to the given process.
 * @ingroup Ecore_Exe_Signal_Group
 */
EAPI void
ecore_exe_quit(Ecore_Exe *exe)
{
   if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
     {
        ECORE_MAGIC_FAIL(exe, ECORE_MAGIC_EXE, "ecore_exe_quit");
        return;
     }
   _ecore_exe_dead_attach(exe);
   kill(exe->pid, SIGQUIT);
}

/**
 * Sends the given spawned process a terminate (@c SIGTERM) signal.
 * @param   exe Process handle to the given process.
 * @ingroup Ecore_Exe_Signal_Group
 */
EAPI void
ecore_exe_terminate(Ecore_Exe *exe)
{
   if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
     {
        ECORE_MAGIC_FAIL(exe, ECORE_MAGIC_EXE, "ecore_exe_terminate");
        return;
     }
   _ecore_exe_dead_attach(exe);
   INF("Sending TERM signal to %s (%d).", exe->cmd, exe->pid);
   kill(exe->pid, SIGTERM);
}

/**
 * Kills the given spawned process by sending it a @c SIGKILL signal.
 * @param   exe Process handle to the given process.
 * @ingroup Ecore_Exe_Signal_Group
 */
EAPI void
ecore_exe_kill(Ecore_Exe *exe)
{
   struct _ecore_exe_dead_exe *dead;

   if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
     {
        ECORE_MAGIC_FAIL(exe, ECORE_MAGIC_EXE, "ecore_exe_kill");
        return;
     }

   dead = calloc(1, sizeof(struct _ecore_exe_dead_exe));
   if (dead)
     {
        dead->pid = exe->pid;
        dead->cmd = strdup(exe->cmd);
        IF_FN_DEL(ecore_timer_del, exe->doomsday_clock);
        exe->doomsday_clock =
           ecore_timer_add(10.0, _ecore_exe_make_sure_its_really_dead, dead);
     }

   INF("Sending KILL signal to %s (%d).", exe->cmd, exe->pid);
   kill(exe->pid, SIGKILL);
}

/**
 * Sends a @c SIGUSR signal to the given spawned process.
 * @param   exe Process handle to the given process.
 * @param   num The number user signal to send.  Must be either 1 or 2, or
 *              the signal will be ignored.
 * @ingroup Ecore_Exe_Signal_Group
 */
EAPI void
ecore_exe_signal(Ecore_Exe *exe, int num)
{
   if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
     {
        ECORE_MAGIC_FAIL(exe, ECORE_MAGIC_EXE, "ecore_exe_signal");
        return;
     }
   if (num == 1)
      kill(exe->pid, SIGUSR1);
   else if (num == 2)
      kill(exe->pid, SIGUSR2);
}

/**
 * Sends a @c SIGHUP signal to the given spawned process.
 * @param   exe Process handle to the given process.
 * @ingroup Ecore_Exe_Signal_Group
 */
EAPI void
ecore_exe_hup(Ecore_Exe *exe)
{
   if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
     {
        ECORE_MAGIC_FAIL(exe, ECORE_MAGIC_EXE, "ecore_exe_hup");
        return;
     }
   kill(exe->pid, SIGHUP);
}

static Ecore_Exe *
_ecore_exe_is_it_alive(pid_t pid)
{
   Ecore_Exe *exe = NULL;

   /* FIXME: There is no nice, safe, OS independant way to tell if a
    * particular PID is still alive.  I have written code to do so
    * for my urunlevel busybox applet (http://urunlevel.sourceforge.net/),
    * but it's for linux only, and still not guaranteed.
    *
    * So for now, we just check that a valid Ecore_Exe structure
    * exists for it.  Even that is not a guarantee, as the structure
    * can be freed without killing the process.
    *
    * I think we can safely put exe's into two categories, those users
    * that care about the life of the exe, and the run and forget type.
    * The run and forget type starts up the exe, then free's the
    * Ecore_Exe structure straight away.  They can never call any of
    * the functions that can call this, so we don't worry about them.
    *
    * Those user's that care about the life of exe's will keep the
    * Ecore_Exe structure around, terminate them eventually, or
    * register for exit events.  For these ones the assumption
    * that valid Ecore_Exe struct == live exe is almost valid.
    *
    * I will probably copy my urunlevel code into here someday.
    */
   exe = _ecore_exe_find(pid);
   if (exe)
     {
        if (!ECORE_MAGIC_CHECK(exe, ECORE_MAGIC_EXE))
           exe = NULL;
     }

   return exe;
}

static int
_ecore_exe_make_sure_its_dead(void *data)
{
   struct _ecore_exe_dead_exe *dead;

   dead = data;
   if (dead)
     {
        Ecore_Exe *exe = NULL;

        if ((exe = _ecore_exe_is_it_alive(dead->pid)) != NULL)
          {
             if (dead->cmd)
                INF("Sending KILL signal to alledgedly dead %s (%d).",
                       dead->cmd, dead->pid);
             else
                INF("Sending KILL signal to alledgedly dead PID %d.",
                    dead->pid);
             exe->doomsday_clock =
                ecore_timer_add(10.0, _ecore_exe_make_sure_its_really_dead,
                                dead);
             kill(dead->pid, SIGKILL);
          }
        else
          {
             IF_FREE(dead->cmd);
             free(dead);
          }
     }
   return 0;
}

static int
_ecore_exe_make_sure_its_really_dead(void *data)
{
   struct _ecore_exe_dead_exe *dead;

   dead = data;
   if (dead)
     {
        Ecore_Exe *exe = NULL;

        if ((exe = _ecore_exe_is_it_alive(dead->pid)) != NULL)
          {
             ERR("RUN!  The zombie wants to eat your brains!  And your CPU!");
             if (dead->cmd)
                INF("%s (%d) is not really dead.", dead->cmd, dead->pid);
             else
                INF("PID %d is not really dead.", dead->pid);
             exe->doomsday_clock = NULL;
          }
        IF_FREE(dead->cmd);
        free(dead);
     }
   return 0;
}

void
_ecore_exe_init(void)
{
   ECORE_EXE_EVENT_ADD = ecore_event_type_new();
   ECORE_EXE_EVENT_DEL = ecore_event_type_new();
   ECORE_EXE_EVENT_DATA = ecore_event_type_new();
   ECORE_EXE_EVENT_ERROR = ecore_event_type_new();
}

void
_ecore_exe_shutdown(void)
{
   while (exes)
     ecore_exe_free(exes);
}

Ecore_Exe *
_ecore_exe_find(pid_t pid)
{
   Ecore_Exe *exe;

   EINA_INLIST_FOREACH(exes, exe)
     {
        if (exe->pid == pid)
           return exe;
     }
   return NULL;
}

Ecore_Timer *
_ecore_exe_doomsday_clock_get(Ecore_Exe *exe)
{
   return exe->doomsday_clock;
}

void
_ecore_exe_doomsday_clock_set(Ecore_Exe *exe, Ecore_Timer *dc)
{
   exe->doomsday_clock = dc;
}

static inline void
_ecore_exe_exec_it(const char *exe_cmd, Ecore_Exe_Flags flags)
{
   char use_sh = 1;
   char *buf = NULL;
   char **args = NULL;
   int  save_errno = 0;

   /* So what is this doing?
    *
    * We are trying to avoid wrapping the exe call with /bin/sh -c.
    * We conservatively search for certain shell meta characters,
    * If we don't find them, we can call the exe directly.
    */
   if (!strpbrk(exe_cmd, "|&;<>()$`\\\"'*?#"))
     {
        char *token;
        char pre_command = 1;
        int num_tokens = 0;

        if (!(buf = strdup(exe_cmd)))
           return;

        token = strtok(buf, " \t\n\v");
        while (token)
          {
             if (token[0] == '~')
               break;
             if (pre_command)
               {
                  if (token[0] == '[')
                    break;
                  if (strchr(token, '='))
                    break;
                  else
                    pre_command = 0;
               }
             num_tokens++;
             token = strtok(NULL, " \t\n\v");
          }
        IF_FREE(buf);
        if ((!token) && (num_tokens))
          {
             int i = 0;

             if (!(buf = strdup(exe_cmd)))
               return;

             token = strtok(buf, " \t\n\v");
             use_sh = 0;
             if (!(args = (char **)calloc(num_tokens + 1, sizeof(char *))))
               {
                  IF_FREE(buf);
                  return;
               }
             for (i = 0; i < num_tokens; i++)
               {
                  if (token)
                    args[i] = token;
                  token = strtok(NULL, " \t\n\v");
               }
             args[num_tokens] = NULL;
          }
     }

   if (!(flags & ECORE_EXE_NOT_LEADER)) setsid();
   if ((flags & ECORE_EXE_USE_SH))
     {
        errno = 0;
        execl("/bin/sh", "/bin/sh", "-c", exe_cmd, (char *)NULL);
     }
   else if (use_sh)
     {                          /* We have to use a shell to run this. */
        if (shell == NULL)
          {                     /* Find users preferred shell. */
             shell = getenv("SHELL");
             if (shell == 0)
               shell = "/bin/sh";
          }
        errno = 0;
        execl(shell, shell, "-c", exe_cmd, (char *)NULL);
     }
   else
     {                          /* We can run this directly. */
        errno = 0;
        execvp(args[0], args);
     }

   save_errno = errno;
   IF_FREE(buf);
   IF_FREE(args);
   errno = save_errno;
   return;
}

static int
_ecore_exe_data_generic_handler(void *data, Ecore_Fd_Handler *fd_handler, Ecore_Exe_Flags flags)
{
   Ecore_Exe *exe;
   int child_fd;
   int event_type;

   exe = data;

   /* Sort out what sort of handler we are. */
   if (flags & ECORE_EXE_PIPE_READ)
     {
        flags = ECORE_EXE_PIPE_READ;
        event_type = ECORE_EXE_EVENT_DATA;
        child_fd = exe->child_fd_read;
     }
   else
     {
        flags = ECORE_EXE_PIPE_ERROR;
        event_type = ECORE_EXE_EVENT_ERROR;
        child_fd = exe->child_fd_error;
     }

   if ((fd_handler)
       && (ecore_main_fd_handler_active_get(fd_handler, ECORE_FD_READ)))
     {
        unsigned char *inbuf;
        int inbuf_num;

        /* Get any left over data from last time. */
        if (flags & ECORE_EXE_PIPE_READ)
          {
             inbuf = exe->read_data_buf;
             inbuf_num = exe->read_data_size;
             exe->read_data_buf = NULL;
             exe->read_data_size = 0;
          }
        else
          {
             inbuf = exe->error_data_buf;
             inbuf_num = exe->error_data_size;
             exe->error_data_buf = NULL;
             exe->error_data_size = 0;
          }

        for (;;)
          {
             int num, lost_exe;
             char buf[READBUFSIZ];

             lost_exe = 0;
             errno = 0;
             if ((num = read(child_fd, buf, READBUFSIZ)) < 1)
               /* FIXME: SPEED/SIZE TRADE OFF - add a smaller READBUFSIZE
                * (currently 64k) to inbuf, use that instead of buf, and
                * save ourselves a memcpy(). */
               {
                  lost_exe = ((errno == EIO) ||
                              (errno == EBADF) ||
                              (errno == EPIPE) ||
                              (errno == EINVAL) || (errno == ENOSPC));
                  if ((errno != EAGAIN) && (errno != EINTR))
                     perror("_ecore_exe_generic_handler() read problem ");
               }
             if (num > 0)
               {                /* data got read. */
                  inbuf = realloc(inbuf, inbuf_num + num);
                  memcpy(inbuf + inbuf_num, buf, num);
                  inbuf_num += num;
               }
             else
               {                /* No more data to read. */
                  if (inbuf)
                    {
                       Ecore_Exe_Event_Data *e;

                       /* Stash the data away for later. */
                       if (flags & ECORE_EXE_PIPE_READ)
                         {
                            exe->read_data_buf = inbuf;
                            exe->read_data_size = inbuf_num;
                         }
                       else
                         {
                            exe->error_data_buf = inbuf;
                            exe->error_data_size = inbuf_num;
                         }

                       if (!(exe->flags & ECORE_EXE_PIPE_AUTO))
                         {
                            e = ecore_exe_event_data_get(exe, flags);
                            if (e)      /* Send the event. */
                              ecore_event_add(event_type, e,
                                              _ecore_exe_event_exe_data_free,
                                              NULL);
                         }
                    }
                  if (lost_exe)
                    {
                       if (flags & ECORE_EXE_PIPE_READ)
                         {
                            if (exe->read_data_size)
                              INF("There are %d bytes left unsent from the dead exe %s.",
                                  exe->read_data_size, exe->cmd);
                         }
                       else
                         {
                            if (exe->error_data_size)
                              INF("There are %d bytes left unsent from the dead exe %s.",
                                  exe->error_data_size, exe->cmd);
                         }
                       /* Thought about this a bit.  If the exe has actually
                        * died, this won't do any harm as it must have died
                        * recently and the pid has not had a chance to recycle.
                        * It is also a paranoid catchall, coz the usual ecore_signal
                        * mechenism should kick in.  But let's give it a good
                        * kick in the head anyway.
                        */
                       ecore_exe_terminate(exe);
                    }
                  break;
               }
          }
     }

   return 1;
}

static int
_ecore_exe_data_error_handler(void *data, Ecore_Fd_Handler *fd_handler)
{
   return _ecore_exe_data_generic_handler(data, fd_handler,
                                          ECORE_EXE_PIPE_ERROR);
}

static int
_ecore_exe_data_read_handler(void *data, Ecore_Fd_Handler *fd_handler)
{
   return _ecore_exe_data_generic_handler(data, fd_handler,
                                          ECORE_EXE_PIPE_READ);
}

static int
_ecore_exe_data_write_handler(void *data, Ecore_Fd_Handler *fd_handler __UNUSED__)
{
   Ecore_Exe *exe;

   exe = data;
   if ((exe->write_fd_handler) &&
       (ecore_main_fd_handler_active_get
        (exe->write_fd_handler, ECORE_FD_WRITE)))
     _ecore_exe_flush(exe);

   /* If we have sent all there is to send, and we need to close the pipe, then close it. */
   if ((exe->close_stdin == 1)
       && (exe->write_data_size == exe->write_data_offset))
     {
        int ok = 0;
        int result;

        INF("Closing stdin for %s", exe->cmd);
        /* if (exe->child_fd_write != -1)  E_NO_ERRNO(result, fsync(exe->child_fd_write), ok);   This a) doesn't work, and b) isn't needed. */
        IF_FN_DEL(ecore_main_fd_handler_del, exe->write_fd_handler);
        if (exe->child_fd_write != -1)
           E_NO_ERRNO(result, close(exe->child_fd_write), ok);
        exe->child_fd_write = -1;
        IF_FREE(exe->write_data_buf);
     }

   return 1;
}

static void
_ecore_exe_flush(Ecore_Exe *exe)
{
   int count;

   /* check whether we need to write anything at all. */
   if ((exe->child_fd_write == -1) || (!exe->write_data_buf))
      return;
   if (exe->write_data_size == exe->write_data_offset)
      return;

   count = write(exe->child_fd_write,
                 (char *)exe->write_data_buf + exe->write_data_offset,
                 exe->write_data_size - exe->write_data_offset);
   if (count < 1)
     {
        if (errno == EIO || errno == EBADF || errno == EPIPE || errno == EINVAL || errno == ENOSPC)     /* we lost our exe! */
          {
             ecore_exe_terminate(exe);
             if (exe->write_fd_handler)
                ecore_main_fd_handler_active_set(exe->write_fd_handler, 0);
          }
     }
   else
     {
        exe->write_data_offset += count;
        if (exe->write_data_offset >= exe->write_data_size)
          {                     /* Nothing left to write, clean up. */
             exe->write_data_size = 0;
             exe->write_data_offset = 0;
             IF_FREE(exe->write_data_buf);
             if (exe->write_fd_handler)
                ecore_main_fd_handler_active_set(exe->write_fd_handler, 0);
          }
     }
}

static void
_ecore_exe_event_exe_data_free(void *data __UNUSED__, void *ev)
{
   Ecore_Exe_Event_Data *e;

   e = ev;
   ecore_exe_event_data_free(e);
}

static Ecore_Exe_Event_Add *
_ecore_exe_event_add_new(void)
{
   Ecore_Exe_Event_Add *e;

   e = calloc(1, sizeof(Ecore_Exe_Event_Add));
   return e;
}

static void
_ecore_exe_event_add_free(void *data __UNUSED__, void *ev)
{
   Ecore_Exe_Event_Add *e;

   e = ev;
   free(e);
}

void               *
_ecore_exe_event_del_new(void)
{
   Ecore_Exe_Event_Del *e;

   e = calloc(1, sizeof(Ecore_Exe_Event_Del));
   return e;
}

void
_ecore_exe_event_del_free(void *data __UNUSED__, void *ev)
{
   Ecore_Exe_Event_Del *e;

   e = ev;
   if (e->exe)
     ecore_exe_free(e->exe);
   free(e);
}

static void
_ecore_exe_dead_attach(Ecore_Exe *exe)
{
   struct _ecore_exe_dead_exe *dead;

   if (exe->doomsday_clock_dead) return;
   dead = calloc(1, sizeof(struct _ecore_exe_dead_exe));
   if (dead)
     {
        dead->pid = exe->pid;
        dead->cmd = strdup(exe->cmd);
        IF_FN_DEL(ecore_timer_del, exe->doomsday_clock);
        exe->doomsday_clock =
           ecore_timer_add(10.0, _ecore_exe_make_sure_its_dead, dead);
        exe->doomsday_clock_dead = dead;
     }
}