sflproco.imp

短小精悍的C语言标准函数库。提供450个以上的可移植的算法和工具代码。

/*  ----------------------------------------------------------------<Prolog>-
    Name:       sflproco.imp
    Title:      process_create_full -- OS/2 implementation
    Package:    Standard Function Library (SFL)

    Written:    1998/10/15  iMatix SFL project team <[e-mail]>
    Revised:    1999/05/13

    Copyright:  Copyright (c) 1996-2000 iMatix Corporation
    License:    This is free software; you can redistribute it and/or modify
                it under the terms of the SFL License Agreement as provided
                in the file LICENSE.TXT.  This software is distributed in
                the hope that it will be useful, but without any warranty.
 ------------------------------------------------------------------</Prolog>-*/

/*  OS/2 implementation of the SFL process_create_full() function            */
/*  This function receives input in the form of a pointer to a PROCESS_DATA  */
/*  structure called procinfo.  See sflproc.c for details.                   */

#   if (!defined (__EMX__))
#       error This function requires the EMX runtime
#   endif

    ARGLIST
        *arglist;                       /*  Argument list                    */
    int
        process = 0,                    /*  Process number                   */
        old_stdin  = NULL_HANDLE,       /*  Dup'd handle for old stdin       */
        old_stdout = NULL_HANDLE,       /*  Dup'd handle for old stdout      */
        old_stderr = NULL_HANDLE;       /*  Dup'd handle for old stderr      */
    Bool
        free_envv = FALSE;              /*  True if we should free envv      */
    const char
        *path,                          /*  Path to search                   */
        *shell,                         /*  Shell to use                     */
        **searchext,                    /*  Extensions to search             */
        *interpreter;                   /*  Name of script interpreter       */
    char
        *full_filename,                 /*  Full filename to run             */
        **argv,                         /*  Arguments for program            */
        **envv,                         /*  Environment for program          */
        *curdir = NULL;                 /*  Current working directory        */

    /*  First, check that minimum arguments needed to do something are set   */
    ASSERT (procinfo);
    if (!procinfo)
        return (NULL_PROCESS);

    ASSERT (procinfo-> filename);
    if (!procinfo-> filename)
      {
        procinfo-> error = EINVAL;
        return (NULL_PROCESS);
      }
    /*  Initialise return information                                        */
    procinfo-> pid        = NULL_PROCESS;
    procinfo-> error      = 0;
    procinfo-> returncode = -1;

    /*  For comparison... Unix version splits into parent & child here...    */

#   include "sflprocx.imp"              /*  Get implementation core          */

    /*  If requested, change to a different root directory, and/or work dir  */
    if (procinfo-> error == 0
    && (procinfo-> rootdir || procinfo-> workdir))
      {
        int
            rc = 0;

        curdir = _getcwd2 (NULL, 256);
        if (curdir == NULL)
            procinfo-> error = errno? errno: EACCES;
        else
          {
            if (procinfo-> rootdir)
                rc = _chdir2 (procinfo-> rootdir);
            if (procinfo-> workdir && rc == 0)
                rc = chdir (procinfo-> workdir);
            if (rc == -1)
              {
                procinfo-> error = errno? errno: EACCES;
                _chdir2 (curdir);       /*  Try to restore existing dir      */
              }
          }
      }

    /*  Now spawn the process                                                */
    if (procinfo-> error == 0)
      {
        int
            spawn_mode;

        /*  Build final argv[] from arglist                                  */
        argv = arglist_to_table (arglist);
        if (argv)
          {
            /*  Spawn the new program, and pick-up its process ID                */
            if (procinfo-> createdaemon)
                spawn_mode = P_DETACH;
            else
                spawn_mode = P_NOWAIT;

            {
              char **ptr = argv;
              fprintf(stderr, "About to run: (%s) ", full_filename);
              for (ptr = argv; *ptr; ptr++)
                 fprintf(stderr, "[%s] ", *ptr);

              fprintf(stderr, "\n");
            }
            process = spawnve (spawn_mode, full_filename, argv, envv);
            procinfo-> pid = ((PROCESS) process);
            if (process <= -1)
                procinfo-> error = errno? errno: EACCES;
            else
            if (procinfo-> wait)
                procinfo-> returncode = waitpid (process, 0, 0);

            mem_free (argv);
          }
        else
          procinfo-> error = errno;
      }

    /*  Put things back the way they were before                             */
    restore_redirection (old_stdin, old_stdout, old_stderr);
    if (curdir != NULL)                 /*  If directory changed, restore it */
      {
        _chdir2 (curdir);
        free (curdir);
      }
    if (free_envv)
        strtfree (envv);
    arglist_free (arglist);
        
    /*  Now, return the process ID or NULL_PROCESS if there was an error     */
    if (procinfo-> error == 0)
        return ((PROCESS) process);
    else
        return (NULL_PROCESS);