| 0,0 → 1,207 |
|---|
| /* |
| * esh - the 'extensible' shell. |
| * |
| * Developed by Godmar Back for CS 3214 Fall 2009 |
| * Virginia Tech. |
| * |
| * $Id: esh.h,v 1.4 2011/03/29 15:46:28 cs3214 Exp $ |
| */ |
| |
| #include <stdbool.h> |
| #include <obstack.h> |
| #include <stdlib.h> |
| #include <termios.h> |
| #include "list.h" |
| |
| /* Forward declarations. */ |
| struct esh_command; |
| struct esh_pipeline; |
| struct esh_command_line; |
| |
| /* |
| * A esh_shell object allows plugins to access services and information. |
| * The shell object should support the following operations. |
| */ |
| struct esh_shell { |
| |
| /* Return the list of current jobs */ |
| struct list/* <esh_pipeline> */ * (* get_jobs) (void); |
| |
| /* Return job corresponding to jid */ |
| struct esh_pipeline * (* get_job_from_jid)(int jid); |
| |
| /* Return job corresponding to pgrp */ |
| struct esh_pipeline * (* get_job_from_pgrp)(pid_t pgrp); |
| |
| /* Return process corresponding to pid */ |
| struct esh_command * (* get_cmd_from_pid)(pid_t pid); |
| |
| /* Build a prompt. Memory must be malloc'd */ |
| char * (* build_prompt) (void); |
| |
| /* Read an input line */ |
| char * (* readline) (const char *prompt); |
| |
| /* Parse command line */ |
| struct esh_command_line * (* parse_command_line) (char *); |
| }; |
| |
| /* |
| * Modules must define a esh_plugin instance named 'esh_module.' |
| * Each of the following members is optional. |
| * esh will call its 'init' functions upon successful load. |
| * |
| * For binary compatibility, do not change the order of these fields. |
| */ |
| struct esh_plugin { |
| struct list_elem elem; /* Link element */ |
| |
| /* an integer number denoting the relative rank of the plugin |
| * Plugins are notified of events in increasing rank. */ |
| int rank; |
| |
| /* Initialize plugin and pass shell object */ |
| bool (* init)(struct esh_shell *); |
| |
| /* The return value of the following three functions indicates |
| * whether the plugin wants processing to stop. |
| * true - indicates processing should stop. |
| * false - indicates processing should continue. |
| */ |
| /* The command line the user entered. |
| * A plugin may change it. */ |
| bool (* process_raw_cmdline)(char **); |
| |
| /* A given pipeline of commands |
| * A plugin may change it. */ |
| bool (* process_pipeline)(struct esh_pipeline *); |
| |
| /* If the command is a built-in provided by a plugin, execute the |
| * command and return true. */ |
| bool (* process_builtin)(struct esh_command *); |
| |
| /* Manufacture part of a prompt. Memory must be allocated via malloc(). |
| * If no plugin implements this, the shell will provide a default prompt. */ |
| char * (* make_prompt)(void); |
| |
| /* The process or processes that are part of a new pipeline |
| * have been forked. |
| * The jid and pgid fields of the pipeline and the pid fields |
| * of all commands in the pipeline are set. |
| * SIGCHLD is blocked. |
| */ |
| void (* pipeline_forked)(struct esh_pipeline *); |
| |
| /* Notify the plugin about a child's status change. |
| * 'waitstatus' is the value returned by waitpid(2) |
| * |
| * May be called from SIGCHLD handler. |
| * The status of the associated pipeline has not yet been |
| * updated. |
| * */ |
| bool (* command_status_change)(struct esh_command *, int waitstatus); |
| |
| /* Add additional fields here if needed. */ |
| }; |
| |
| /* A command line may contain multiple pipelines. */ |
| struct esh_command_line { |
| struct list/* <esh_pipeline> */ pipes; /* List of pipelines */ |
| |
| /* Add additional fields here if needed. */ |
| }; |
| |
| enum job_status { |
| FOREGROUND, /* job is running in foreground. Only one job can be |
| in the foreground state. */ |
| BACKGROUND, /* job is running in background */ |
| STOPPED, /* job is stopped via SIGSTOP */ |
| NEEDSTERMINAL, /* job is stopped because it was a background job |
| and requires exclusive terminal access */ |
| COMPLETED, |
| TERMINATED, |
| }; |
| |
| /* A pipeline is a list of one or more commands. |
| * For the purposes of job control, a pipeline forms one job. |
| */ |
| struct esh_pipeline { |
| struct list/* <esh_command> */ commands; /* List of commands */ |
| char *iored_input; /* If non-NULL, first command should read from |
| file 'iored_input' */ |
| char *iored_output; /* If non-NULL, last command should write to |
| file 'iored_output' */ |
| bool append_to_output; /* True if user typed >> to append */ |
| bool bg_job; /* True if user entered & */ |
| struct list_elem elem; /* Link element. */ |
| |
| int jid; /* Job id. */ |
| pid_t pgrp; /* Process group. */ |
| enum job_status status; /* Job status. */ |
| struct termios saved_tty_state; /* The state of the terminal when this job was |
| stopped after having been in foreground */ |
| |
| /* Add additional fields here if needed. */ |
| char cmd_string[256]; /* Command string */ |
| }; |
| |
| /* A command is part of a pipeline. */ |
| struct esh_command { |
| char **argv; /* NULL terminated array of pointers to words |
| making up this command. */ |
| char *iored_input; /* If non-NULL, command should read from |
| file 'iored_input' */ |
| char *iored_output; /* If non-NULL, command should write to |
| file 'iored_output' */ |
| bool append_to_output; /* True if user typed >> to append */ |
| struct list_elem elem; /* Link element to link commands in pipeline. */ |
| |
| pid_t pid; /* Process id. */ |
| struct esh_pipeline * pipeline; |
| /* The pipeline of which this job is a part. */ |
| |
| /* Add additional fields here if needed. */ |
| }; |
| |
| /** ----------------------------------------------------------- */ |
| |
| /* Create new command structure and initialize it */ |
| struct esh_command * esh_command_create(char ** argv, |
| char *iored_input, |
| char *iored_output, |
| bool append_to_output); |
| |
| /* Create a new pipeline containing only one command */ |
| struct esh_pipeline * esh_pipeline_create(struct esh_command *cmd); |
| |
| /* Complete a pipe's setup by copying I/O redirection information |
| * from first and last command */ |
| void esh_pipeline_finish(struct esh_pipeline *pipe); |
| |
| /* Create an empty command line */ |
| struct esh_command_line * esh_command_line_create_empty(void); |
| |
| /* Create a command line with a single pipeline */ |
| struct esh_command_line * esh_command_line_create(struct esh_pipeline *pipe); |
| |
| /* Deallocation functions */ |
| void esh_command_line_free(struct esh_command_line *); |
| void esh_pipeline_free(struct esh_pipeline *); |
| void esh_command_free(struct esh_command *); |
| |
| /* Print functions */ |
| void esh_command_print(struct esh_command *cmd); |
| void esh_pipeline_print(struct esh_pipeline *pipe); |
| void esh_command_line_print(struct esh_command_line *line); |
| |
| /* Parse a command line. Implemented in esh-grammar.y */ |
| struct esh_command_line * esh_parse_command_line(char * line); |
| |
| /* Load plugins from directory dir */ |
| void esh_plugin_load_from_directory(char *dirname); |
| |
| /* Initialize loaded plugins */ |
| void esh_plugin_initialize(struct esh_shell *shell); |
| |
| /* List of loaded plugins */ |
| extern struct list esh_plugin_list; |