Custom readline commands for explicit completions

New commands:
  - rc-complete-command, per default bound to "M-!"
  - rc-complete-filename, "M-/"
  - rc-complete-variable, "M-$"

These commands are useful, if one wants a specific type of completion which is
not performed by the context-senstive default one, e.g. filename completion at
the beginning of the line or command completion for the second word (after
sudo).

The readline code now also sets the application name to "rc", making it
possible to specify different bindings for these commands in ~/.inputrc:
  $if rc
  "\C-x\C-[": rc-complete-command
  "\C-[\C-x": rc-complete-filename
  "\C-x\C-v": rc-complete-variable
  $endif

1 files changed, 33 insertions, 2 deletions

diff --git a/edit-readline.c b/edit-readline.c
index 9737e3e..fb9044e 100644
--- a/edit-readline.c
+++ b/edit-readline.c
@@ -94,15 +94,38 @@ static rl_compentry_func_t *compl_func(const char *text, int start, int end) {
 	return NULL;
 }
 
-static char **rc_completion(const char *text, int start, int end) {
-	rl_compentry_func_t *func = compl_func(text, start, end);
+static rl_compentry_func_t *compentry_func;
 
+static char **rc_completion(const char *text, int start, int end) {
+	rl_compentry_func_t *func;
+
+	if (compentry_func != NULL) {
+		func = compentry_func;
+		compentry_func = NULL;
+		rl_attempted_completion_over = 1;
+	} else
+		func = compl_func(text, start, end);
 	if (func != NULL)
 		return rl_completion_matches(text, func);
 	else
 		return NULL;
 }
 
+static int rc_complete_command(int count, int key) {
+	compentry_func = compl_extcmd;
+	return rl_complete(count, key);
+}
+
+static int rc_complete_filename(int count, int key) {
+	compentry_func = rl_filename_completion_function;
+	return rl_complete(count, key);
+}
+
+static int rc_complete_variable(int count, int key) {
+	compentry_func = compl_var;
+	return rl_complete(count, key);
+}
+
 void *edit_begin(int fd) {
 	List *hist;
 	struct cookie *c;
@@ -112,6 +135,14 @@ void *edit_begin(int fd) {
 	rl_catch_signals = 0;
 	rl_completer_quote_characters = "'";
 	rl_filename_quote_characters = "\t\n !#$&'()*;<=>?@[\\]^`{|}~";
+	rl_readline_name = "rc";
+
+	rl_add_funmap_entry("rc-complete-command",  rc_complete_command);
+	rl_add_funmap_entry("rc-complete-filename", rc_complete_filename);
+	rl_add_funmap_entry("rc-complete-variable", rc_complete_variable);
+	rl_bind_keyseq("\e!", rc_complete_command);
+	rl_bind_keyseq("\e/", rc_complete_filename);
+	rl_bind_keyseq("\e$", rc_complete_variable);
 
 	hist = varlookup("history");
 	if (hist != NULL)