/**************************************************************************** * apps/nshlib/nsh_builtin.c * * Originally by: * * Copyright (C) 2011 Uros Platise. All rights reserved. * Author: Uros Platise * * With subsequent updates, modifications, and general maintenance by: * * Copyright (C) 2011-2013 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name NuttX nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /**************************************************************************** * Included Files ****************************************************************************/ #include #ifdef CONFIG_SCHED_WAITPID # include #endif #include #include #include #include #include #include "nsh.h" #include "nsh_console.h" #ifdef CONFIG_NSH_BUILTIN_APPS /**************************************************************************** * Pre-processor Definitions ****************************************************************************/ /**************************************************************************** * Private Types ****************************************************************************/ /**************************************************************************** * Private Function Prototypes ****************************************************************************/ /**************************************************************************** * Private Data ****************************************************************************/ /**************************************************************************** * Public Data ****************************************************************************/ /**************************************************************************** * Private Functions ****************************************************************************/ /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: nsh_builtin * * Description: * Attempt to execute the application task whose name is 'cmd' * * Returned Value: * <0 If exec_builtin() fails, then the negated errno value * is returned. * -1 (ERROR) if the application task corresponding to 'cmd' could not * be started (possibly because it doesn not exist). * 0 (OK) if the application task corresponding to 'cmd' was * and successfully started. If CONFIG_SCHED_WAITPID is * defined, this return value also indicates that the * application returned successful status (EXIT_SUCCESS) * 1 If CONFIG_SCHED_WAITPID is defined, then this return value * indicates that the application task was spawned successfully * but returned failure exit status. * ****************************************************************************/ int nsh_builtin(FAR struct nsh_vtbl_s *vtbl, FAR const char *cmd, FAR char **argv, FAR const char *redirfile, int oflags) { int ret = OK; /* Lock the scheduler in an attempt to prevent the application from * running until waitpid() has been called. */ sched_lock(); /* Try to find and execute the command within the list of builtin * applications. */ ret = exec_builtin(cmd, (FAR char * const *)argv, redirfile, oflags); if (ret >= 0) { /* The application was successfully started with pre-emption disabled. * In the simplest cases, the application will not have run because the * the scheduler is locked. But in the case where I/O was redirected, a * proxy task ran and broke our lock. As result, the application may * have aso ran if its priority was higher than than the priority of * this thread. * * If the application did not run to completion and if the application * was not backgrounded, then we need to wait here for the application * to exit. This only works works with the following options: * * - CONFIG_NSH_DISABLEBG - Do not run commands in background * - CONFIG_SCHED_WAITPID - Required to run external commands in * foreground */ #ifdef CONFIG_SCHED_WAITPID /* CONFIG_SCHED_WAITPID is selected, so we may run the command in * foreground unless we were specifically requested to run the command * in background (and running commands in background is enabled). */ # ifndef CONFIG_NSH_DISABLEBG if (vtbl->np.np_bg == false) # endif /* CONFIG_NSH_DISABLEBG */ { int rc = 0; /* Wait for the application to exit. We did lock the scheduler * above, but that does not guarantee that the application did not * already run to completion in the case where I/O was redirected. * Here the scheduler will be unlocked while waitpid is waiting * and if the application has not yet run, it will now be able to * do so. * * Also, if CONFIG_SCHED_HAVE_PARENT is defined waitpid() might fail * even if task is still active: If the I/O was re-directed by a * proxy task, then the ask is a child of the proxy, and not this * task. waitpid() fails with ECHILD in either case. */ ret = waitpid(ret, &rc, 0); if (ret < 0) { /* If the child thread does not exist, waitpid() will return * the error ECHLD. Since we know that the task was successfully * started, this must be one of the cases described above; we * have to assume that the task already exit'ed. In this case, * we have no idea if the application ran successfully or not * (because NuttX does not retain exit status of child tasks). * Let's assume that is did run successfully. */ int errcode = errno; if (errcode == ECHILD) { ret = OK; } else { nsh_output(vtbl, g_fmtcmdfailed, cmd, "waitpid", NSH_ERRNO_OF(errcode)); } } /* Waitpid completed the wait successfully */ else { /* We can't return the exact status (nsh has nowhere to put it) * so just pass back zero/nonzero in a fashion that doesn't look * like an error. */ ret = (rc == 0) ? OK : 1; /* TODO: Set the environment variable '?' to a string corresponding * to WEXITSTATUS(rc) so that $? will expand to the exit status of * the most recently executed task. */ } } # ifndef CONFIG_NSH_DISABLEBG else # endif /* CONFIG_NSH_DISABLEBG */ #endif /* CONFIG_SCHED_WAITPID */ /* We get here if either: * * - CONFIG_SCHED_WAITPID is not selected meaning that all commands * have to be run in background, or * - CONFIG_SCHED_WAITPID and CONFIG_NSH_DISABLEBG are both selected, but the * user requested to run the command in background. * * NOTE that the case of a) CONFIG_SCHED_WAITPID is not selected and * b) CONFIG_NSH_DISABLEBG selected cannot be supported. In that event, all * commands will have to run in background. The waitpid() API must be * available to support running the command in foreground. */ #if !defined(CONFIG_SCHED_WAITPID) || !defined(CONFIG_NSH_DISABLEBG) { struct sched_param param; sched_getparam(ret, ¶m); nsh_output(vtbl, "%s [%d:%d]\n", cmd, ret, param.sched_priority); /* Backgrounded commands always 'succeed' as long as we can start * them. */ ret = OK; } #endif /* !CONFIG_SCHED_WAITPID || !CONFIG_NSH_DISABLEBG */ } sched_unlock(); /* If exec_builtin() or waitpid() failed, then return -1 (ERROR) with the * errno value set appropriately. */ if (ret < 0) { return ERROR; } return ret; } #endif /* CONFIG_NSH_BUILTIN_APPS */