/**************************************************************************** * apps/nshlib/nsh_fileapps.c * * Copyright (C) 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 "nsh.h" #include "nsh_console.h" #ifdef CONFIG_NSH_FILE_APPS /**************************************************************************** * Public Functions ****************************************************************************/ /**************************************************************************** * Name: nsh_fileapp * * Description: * Attempt to execute the application task whose name is 'cmd' * * Returned Value: * <0 If posix_spawn() 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_fileapp(FAR struct nsh_vtbl_s *vtbl, FAR const char *cmd, FAR char **argv, FAR const char *redirfile, int oflags) { posix_spawn_file_actions_t file_actions; posix_spawnattr_t attr; pid_t pid; int ret; /* Initialize the attributes file actions structure */ ret = posix_spawn_file_actions_init(&file_actions); if (ret != 0) { /* posix_spawn_file_actions_init returns a positive errno value on * failure. */ nsh_output(vtbl, g_fmtcmdfailed, cmd, "posix_spawn_file_actions_init", NSH_ERRNO_OF(ret)); goto errout; } ret = posix_spawnattr_init(&attr); if (ret != 0) { /* posix_spawnattr_init returns a positive errno value on failure. */ nsh_output(vtbl, g_fmtcmdfailed, cmd, "posix_spawnattr_init", NSH_ERRNO); goto errout_with_actions; } /* Handle re-direction of output */ if (redirfile) { ret = posix_spawn_file_actions_addopen(&file_actions, 1, redirfile, oflags, 0644); if (ret != 0) { /* posix_spawn_file_actions_addopen returns a positive errno * value on failure. */ nsh_output(vtbl, g_fmtcmdfailed, cmd, "posix_spawn_file_actions_addopen", NSH_ERRNO); goto errout_with_attrs; } } /* Lock the scheduler in an attempt to prevent the application from * running until waitpid() has been called. */ sched_lock(); /* Execute the program. posix_spawnp returns a positive errno value on * failure. */ ret = posix_spawnp(&pid, cmd, &file_actions, &attr, &argv[1], NULL); if (ret == OK) { /* 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. */ ret = waitpid(pid, &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(); /* Free attibutes and file actions. Ignoring return values in the case * of an error. */ errout_with_actions: (void)posix_spawn_file_actions_destroy(&file_actions); errout_with_attrs: (void)posix_spawnattr_destroy(&attr); errout: /* Most posix_spawn interfaces return a positive errno value on failure * and do not set the errno variable. */ if (ret > 0) { /* Set the errno value and return -1 */ set_errno(ret); ret = ERROR; } else if (ret < 0) { /* Return -1 on failure. errno should have been set. */ ret = ERROR; } return ret; } #endif /* CONFIG_NSH_FILE_APPS */