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Diffstat (limited to 'apps/nshlib/nsh_fileapps.c')
| -rw-r--r-- | apps/nshlib/nsh_fileapps.c | 314 |
1 files changed, 314 insertions, 0 deletions
diff --git a/apps/nshlib/nsh_fileapps.c b/apps/nshlib/nsh_fileapps.c new file mode 100644 index 000000000..9ff230f1a --- /dev/null +++ b/apps/nshlib/nsh_fileapps.c @@ -0,0 +1,314 @@ +/**************************************************************************** + * apps/nshlib/nsh_fileapps.c + * + * Copyright (C) 2013 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <gnutt@nuttx.org> + * + * 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 <nuttx/config.h> + +#ifdef CONFIG_SCHED_WAITPID +# include <sys/wait.h> +#endif + +#include <stdbool.h> +#include <spawn.h> +#include <errno.h> +#include <string.h> + +#include "nsh.h" +#include "nsh_console.h" + +#ifdef CONFIG_NSH_FILE_APPS + +/**************************************************************************** + * Definitions + ****************************************************************************/ + +/**************************************************************************** + * Private Types + ****************************************************************************/ + +/**************************************************************************** + * Private Function Prototypes + ****************************************************************************/ + +/**************************************************************************** + * Private Data + ****************************************************************************/ + +/**************************************************************************** + * Public Data + ****************************************************************************/ + +/**************************************************************************** + * Private Functions + ****************************************************************************/ + +/**************************************************************************** + * Public Functions + ****************************************************************************/ + +/**************************************************************************** + * Name: nsh_fileapp + * + * 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_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 */ |