+ error (_("REGEXP string is empty"));
+
+ code = regcomp (&pattern, searchstr, REG_ICASE);
+ if (code == 0)
+ {
+ struct cleanup *cleanups;
+
+ cleanups = make_regfree_cleanup (&pattern);
+ apropos_cmd (gdb_stdout, cmdlist, &pattern, "");
+ do_cleanups (cleanups);
+ }
+ else
+ {
+ char *err = get_regcomp_error (code, &pattern);
+
+ make_cleanup (xfree, err);
+ error (_("Error in regular expression: %s"), err);
+ }
+}
+
+/* Subroutine of alias_command to simplify it.
+ Return the first N elements of ARGV flattened back to a string
+ with a space separating each element.
+ ARGV may not be NULL.
+ This does not take care of quoting elements in case they contain spaces
+ on purpose. */
+
+static dyn_string_t
+argv_to_dyn_string (char **argv, int n)
+{
+ int i;
+ dyn_string_t result = dyn_string_new (10);
+
+ gdb_assert (argv != NULL);
+ gdb_assert (n >= 0 && n <= countargv (argv));
+
+ for (i = 0; i < n; ++i)
+ {
+ if (i > 0)
+ dyn_string_append_char (result, ' ');
+ dyn_string_append_cstr (result, argv[i]);
+ }
+
+ return result;
+}
+
+/* Subroutine of alias_command to simplify it.
+ Return TRUE if COMMAND exists, unambiguously. Otherwise FALSE. */
+
+static int
+valid_command_p (const char *command)
+{
+ struct cmd_list_element *c;
+
+ c = lookup_cmd_1 (& command, cmdlist, NULL, 1);
+
+ if (c == NULL || c == (struct cmd_list_element *) -1)
+ return FALSE;
+
+ /* This is the slightly tricky part.
+ lookup_cmd_1 will return a pointer to the last part of COMMAND
+ to match, leaving COMMAND pointing at the remainder. */
+ while (*command == ' ' || *command == '\t')
+ ++command;
+ return *command == '\0';
+}
+
+/* Make an alias of an existing command. */
+
+static void
+alias_command (char *args, int from_tty)
+{
+ int i, alias_argc, command_argc;
+ int abbrev_flag = 0;
+ char *args2, *equals, *alias, *command;
+ char **alias_argv, **command_argv;
+ dyn_string_t alias_dyn_string, command_dyn_string;
+ struct cleanup *cleanup;
+ static const char usage[] = N_("Usage: alias [-a] [--] ALIAS = COMMAND");
+
+ if (args == NULL || strchr (args, '=') == NULL)
+ error (_(usage));
+
+ args2 = xstrdup (args);
+ cleanup = make_cleanup (xfree, args2);
+ equals = strchr (args2, '=');
+ *equals = '\0';
+ alias_argv = gdb_buildargv (args2);
+ make_cleanup_freeargv (alias_argv);
+ command_argv = gdb_buildargv (equals + 1);
+ make_cleanup_freeargv (command_argv);
+
+ for (i = 0; alias_argv[i] != NULL; )
+ {
+ if (strcmp (alias_argv[i], "-a") == 0)
+ {
+ ++alias_argv;
+ abbrev_flag = 1;
+ }
+ else if (strcmp (alias_argv[i], "--") == 0)
+ {
+ ++alias_argv;
+ break;
+ }
+ else
+ break;
+ }
+
+ if (alias_argv[0] == NULL || command_argv[0] == NULL
+ || *alias_argv[0] == '\0' || *command_argv[0] == '\0')
+ error (_(usage));
+
+ for (i = 0; alias_argv[i] != NULL; ++i)
+ {
+ if (! valid_user_defined_cmd_name_p (alias_argv[i]))
+ {
+ if (i == 0)
+ error (_("Invalid command name: %s"), alias_argv[i]);
+ else
+ error (_("Invalid command element name: %s"), alias_argv[i]);
+ }
+ }