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Diffstat (limited to 'apps/nshlib/nsh_builtin.c')
-rw-r--r-- | apps/nshlib/nsh_builtin.c | 262 |
1 files changed, 262 insertions, 0 deletions
diff --git a/apps/nshlib/nsh_builtin.c b/apps/nshlib/nsh_builtin.c new file mode 100644 index 000000000..0d5a0231c --- /dev/null +++ b/apps/nshlib/nsh_builtin.c @@ -0,0 +1,262 @@ +/**************************************************************************** + * apps/nshlib/nsh_builtin.c + * + * Originally by: + * + * Copyright (C) 2011 Uros Platise. All rights reserved. + * Author: Uros Platise <uros.platise@isotel.eu> + * + * With subsequent updates, modifications, and general maintenance by: + * + * Copyright (C) 2011-2013 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 <errno.h> +#include <string.h> + +#include <nuttx/binfmt/builtin.h> +#include <apps/builtin.h> + +#include "nsh.h" +#include "nsh_console.h" + +#ifdef CONFIG_NSH_BUILTIN_APPS + +/**************************************************************************** + * 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 const char **)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 */ |