Add an option (history-file) for a file to save/restore command prompt

history, from Olof-Joachim Frahm.

options-table.c

@@ -83,6 +83,11 @@ const struct options_table_entry server_options_table[] = {
 	  .default_num = 0
 	},
 
+	{ .name = "history-file",
+	  .type = OPTIONS_TABLE_STRING,
+	  .default_str = NULL
+	},
+
 	{ .name = "message-limit",
 	  .type = OPTIONS_TABLE_NUMBER,
 	  .minimum = 0,

server.c

@@ -240,6 +240,7 @@ server_start(int lockfd, char *lockfile)
 			cfg_add_cause("%s: %s", cfg_file, cause);
 	}
 	cmdq_continue(cfg_cmd_q);
+	status_prompt_load_history();
 
 	server_add_accept(0);
 
@@ -250,6 +251,7 @@ server_start(int lockfd, char *lockfile)
 
 	set_signals(server_signal_callback);
 	server_loop();
+	status_prompt_save_history();
 	exit(0);
 }
 

status.c

@@ -47,11 +47,102 @@ const char **status_prompt_complete_list(u_int *, const char *);
 char   *status_prompt_complete_prefix(const char **, u_int);
 char   *status_prompt_complete(struct session *, const char *);
 
+char   *status_prompt_find_history_file(void);
+
 /* Status prompt history. */
 #define PROMPT_HISTORY 100
 char	**status_prompt_hlist;
 u_int	  status_prompt_hsize;
 
+/* Find the history file to load/save from/to. */
+char *
+status_prompt_find_history_file(void)
+{
+	const char	*home, *history_file;
+	char		*path;
+
+	history_file = options_get_string(&global_options, "history-file");
+	if (*history_file == '\0')
+		return (NULL);
+	if (*history_file == '/')
+		return (xstrdup(history_file));
+
+	if (history_file[0] != '~' || history_file[1] != '/')
+		return (NULL);
+	if ((home = find_home()) == NULL)
+		return (NULL);
+	xasprintf(&path, "%s%s", home, history_file + 1);
+	return (path);
+}
+
+/* Load status prompt history from file. */
+void
+status_prompt_load_history(void)
+{
+	FILE	*f;
+	char	*history_file, *line, *tmp;
+	size_t	 length;
+
+	if ((history_file = status_prompt_find_history_file()) == NULL)
+		return;
+	log_debug("loading history from %s", history_file);
+
+	f = fopen(history_file, "r");
+	if (f == NULL) {
+		log_debug("%s: %s", history_file, strerror(errno));
+		free(history_file);
+		return;
+	}
+	free(history_file);
+
+	for (;;) {
+		if ((line = fgetln(f, &length)) == NULL)
+			break;
+
+		if (length > 0) {
+			if (line[length - 1] == '\n') {
+				line[length - 1] = '\0';
+				status_prompt_add_history(line);
+			} else {
+				tmp = xmalloc(length + 1);
+				memcpy(tmp, line, length);
+				tmp[length] = '\0';
+				status_prompt_add_history(tmp);
+				free(tmp);
+			}
+		}
+	}
+	fclose(f);
+}
+
+/* Save status prompt history to file. */
+void
+status_prompt_save_history(void)
+{
+	FILE	*f;
+	u_int	 i;
+	char	*history_file;
+
+	if ((history_file = status_prompt_find_history_file()) == NULL)
+		return;
+	log_debug("saving history to %s", history_file);
+
+	f = fopen(history_file, "w");
+	if (f == NULL) {
+		log_debug("%s: %s", history_file, strerror(errno));
+		free(history_file);
+		return;
+	}
+	free(history_file);
+
+	for (i = 0; i < status_prompt_hsize; i++) {
+		fputs(status_prompt_hlist[i], f);
+		fputc('\n', f);
+	}
+	fclose(f);
+
+}
+
 /* Status output tree. */
 RB_GENERATE(status_out_tree, status_out, entry, status_out_cmp);
 

tmux.1

@@ -2396,6 +2396,10 @@ passed through to applications running in
 .Nm .
 Attached clients should be detached and attached again after changing this
 option.
+.It Ic history-file Ar path
+If not empty, a file to which
+.Nm
+will write command prompt history on exit and load it from on start.
 .It Ic message-limit Ar number
 Set the number of error or information messages to save in the message log for
 each client.

tmux.c

@@ -198,10 +198,27 @@ shell_exec(const char *shell, const char *shellcmd)
 	fatal("execl failed");
 }
 
+const char*
+find_home(void)
+{
+	struct passwd	*pw;
+	const char	*home;
+
+	home = getenv("HOME");
+	if (home == NULL || *home == '\0') {
+		pw = getpwuid(getuid());
+		if (pw != NULL)
+			home = pw->pw_dir;
+		else
+			home = NULL;
+	}
+
+	return home;
+}
+
 int
 main(int argc, char **argv)
 {
-	struct passwd	*pw;
 	char		*s, *path, *label, **var, tmp[PATH_MAX];
 	char		 in[256];
 	const char	*home;
@@ -320,14 +337,7 @@ main(int argc, char **argv)
 
 	/* Locate the configuration file. */
 	if (cfg_file == NULL) {
-		home = getenv("HOME");
-		if (home == NULL || *home == '\0') {
-			pw = getpwuid(getuid());
-			if (pw != NULL)
-				home = pw->pw_dir;
-			else
-				home = NULL;
-		}
+		home = find_home();
 		if (home != NULL) {
 			xasprintf(&cfg_file, "%s/.tmux.conf", home);
 			if (access(cfg_file, R_OK) != 0 && errno == ENOENT) {

tmux.h

@@ -1469,6 +1469,7 @@ int		 checkshell(const char *);
 int		 areshell(const char *);
 void		 setblocking(int, int);
 __dead void	 shell_exec(const char *, const char *);
+const char	*find_home(void);
 
 /* cfg.c */
 extern struct cmd_q *cfg_cmd_q;
@@ -1943,6 +1944,8 @@ void	 status_prompt_clear(struct client *);
 int	 status_prompt_redraw(struct client *);
 void	 status_prompt_key(struct client *, int);
 void	 status_prompt_update(struct client *, const char *, const char *);
+void	 status_prompt_load_history(void);
+void	 status_prompt_save_history(void);
 
 /* resize.c */
 void	 recalculate_sizes(void);