hdt: Implement aliases

Impact: New alias feature; CLi backward compatible

`dmi' is now a shorthand for `set mode dmi' (idem for all modes). This
is performed via a new routine: expand_aliases.

It is now also possible to match aliases (e.g. `q', `quit') to a single
valid command (e.g. `exit'). The list needs to be populated manually and
is intented to be kept short. Eventually, the CLI will support
autocompletion that will help user experience.

Signed-off-by: Pierre-Alexandre Meyer <pierre@mouraf.org>

diff --git a/com32/hdt/hdt-cli.c b/com32/hdt/hdt-cli.c
index c964d58..12bbb98 100644 (file)
--- a/com32/hdt/hdt-cli.c
+++ b/com32/hdt/hdt-cli.c
@@ -44,6 +44,28 @@ struct cli_mode_descr *list_modes[] = {
        &vesa_mode,
 };
 
+/*
+ * .aliases = {"q", "quit"} won't work since it is an array of pointers, not an
+ * array of variables. There is no easy way around it besides declaring the arrays of
+ * strings first.
+ */
+char *exit_aliases[] = {"q", "quit"};
+char *help_aliases[] = {"h"};
+
+/* List of aliases */
+struct cli_alias hdt_aliases[] = {
+       {
+               .command = CLI_EXIT,
+               .nb_aliases = 2,
+               .aliases = exit_aliases,
+       },
+       {
+               .command = CLI_HELP,
+               .nb_aliases = 1,
+               .aliases = help_aliases,
+       },
+};
+
 /**
  * set_mode - set the current mode of the cli
  * @mode:      mode to set
@@ -165,8 +187,77 @@ void find_cli_mode_descr(cli_mode_t mode, struct cli_mode_descr **mode_found)
 }
 
 /**
+ * expand_aliases - resolve aliases mapping
+ * @line:      command line to parse
+ * @command:   first token in the line
+ * @module:    second token in the line
+ * @argc:      number of arguments
+ * @argv:      array of arguments
+ *
+ * We maintain a small list of static alises to enhance user experience.
+ * Only commands can be aliased (first token). Otherwise it can become really hairy...
+ **/
+static void expand_aliases(char *line __unused, char **command, char **module,
+                          int *argc, char **argv)
+{
+       struct cli_mode_descr *mode;
+       int i, j;
+
+       find_cli_mode_descr(mode_s_to_mode_t(*command), &mode);
+       if (mode != NULL && *module == NULL) {
+               /*
+                * The user specified a mode instead of `set mode...', e.g.
+                * `dmi' instead of `set mode dmi'
+                */
+
+               /* *argv is NULL since *module is NULL */
+               *argc = 1;
+               *argv = malloc(*argc * sizeof(char *));
+               argv[0] = malloc((sizeof(*command) + 1) * sizeof(char));
+               strncpy(argv[0], *command, sizeof(*command) + 1);
+               dprintf("CLI DEBUG: ALIAS %s ", *command);
+
+               strncpy(*command, CLI_SET, sizeof(CLI_SET));    /* set */
+
+               *module = malloc(sizeof(CLI_MODE) * sizeof(char));
+               strncpy(*module, CLI_MODE, sizeof(CLI_MODE));   /* mode */
+
+               dprintf("--> %s %s %s\n", *command, *module, argv[0]);
+               goto out;
+       }
+
+       /* Simple aliases mapping a single command to another one */
+       for (i = 0; i < MAX_ALIASES; i++) {
+               for (j = 0; j < hdt_aliases[i].nb_aliases; j++) {
+                       if (!strncmp(*command, hdt_aliases[i].aliases[j],
+                           sizeof(hdt_aliases[i].aliases[j]))) {
+                               dprintf("CLI DEBUG: ALIAS %s ", *command);
+                               strncpy(*command, hdt_aliases[i].command,
+                                       sizeof(hdt_aliases[i].command) + 1);
+                               dprintf("--> %s\n", *command);
+                               goto out; /* Don't allow chaining aliases */
+                       }
+               }
+       }
+       return;
+
+out:
+       dprintf("CLI DEBUG: New parameters:\n");
+       dprintf("CLI DEBUG: command = %s\n", *command);
+       dprintf("CLI DEBUG: module  = %s\n", *module);
+       dprintf("CLI DEBUG: argc    = %d\n", *argc);
+       for (i = 0; i < *argc; i++)
+               dprintf("CLI DEBUG: argv[%d] = %s\n", i, argv[0]);
+       return;
+}
+
+/**
  * parse_command_line - low level parser for the command line
- * @command:   command line to parse
+ * @line:      command line to parse
+ * @command:   first token in the line
+ * @module:    second token in the line
+ * @argc:      number of arguments
+ * @argv:      array of arguments
  *
  * The format of the command line is:
  *     <main command> [<module on which to operate> [<args>]]
@@ -225,7 +316,8 @@ static void parse_command_line(char *line, char **command, char **module,
        pch = strtok(line + args_pos, CLI_SPACE);
        while (pch != NULL) {
                dprintf("CLI DEBUG: argv[%d] = %s\n", argc_iter, pch);
-               argv[argc_iter] = pch;
+               argv[argc_iter] = malloc(sizeof(pch) * sizeof(char));
+               strncpy(argv[argc_iter], pch, sizeof(pch));
                argc_iter++;
                pch = strtok(NULL, CLI_SPACE);
        }
@@ -259,6 +351,7 @@ void find_cli_callback_descr(const char* module_name,
 
        if (modules_iter != modules_list->nb_modules) {
                *module_found = &(modules_list->modules[modules_iter]);
+               dprintf("CLI DEBUG: module %s found\n", (*module_found)->name);
                return;
        }
 
@@ -273,7 +366,7 @@ not_found:
 static void exec_command(char *line,
                         struct s_hardware *hardware)
 {
-       int argc = 0;
+       int argc, i = 0;
        char *command = NULL, *module = NULL;
        char **argv = NULL;
        struct cli_callback_descr* current_module = NULL;
@@ -290,7 +383,11 @@ static void exec_command(char *line,
        /* This will allocate memory that will need to be freed */
        parse_command_line(line, &command, &module, &argc, argv);
 
+       /* Expand shortcuts, if needed */
+       expand_aliases(line, &command, &module, &argc, argv);
+
        if (module == NULL) {
+               dprintf("CLI DEBUG: single command detected\n", CLI_SHOW);
                /*
                 * A single word was specified: look at the list of default
                 * commands in the current mode to see if there is a match.
@@ -361,6 +458,8 @@ static void exec_command(char *line,
        /* Let's not forget to clean ourselves */
        free(command);
        free(module);
+       for (i = 0; i < argc; i++)
+               free(argv[i]);
        free(argv);
 }
 

diff --git a/com32/hdt/hdt-cli.h b/com32/hdt/hdt-cli.h
index aad9db8..9101ada 100644 (file)
--- a/com32/hdt/hdt-cli.h
+++ b/com32/hdt/hdt-cli.h
@@ -118,6 +118,14 @@ struct cli_callback_descr {
        void ( * exec ) ( int argc, char** argv, struct s_hardware *hardware );
 };
 
+/* Manage aliases */
+#define MAX_ALIASES 2
+struct cli_alias {
+       const char *command;    /* Original command */
+       const int nb_aliases;   /* Size of aliases array */
+       const char **aliases;   /* List of aliases */
+};
+
 /* List of implemented modes */
 #define MAX_MODES 8
 struct cli_mode_descr *list_modes[MAX_MODES];