Let SIGUSR1 trigger a reload

In an effort to better integrate the import process with external
applications, it's desirable to have a mechanism by which external
programs can trigger a reload of calcurse's data.

This patch adds that functionality via SIGUSR1. The reload request is
handled in the main loop. When the user is currently entering data, the
request is delayed until the main loop is re-entered.

Signed-off-by: Tim Hentenaar <tim@hentenaar.com>
Signed-off-by: Lukas Fleischer <calcurse@cryptocrack.de>

src/calcurse.c

@@ -625,6 +625,11 @@ int main(int argc, char **argv)
 			wins_reset();
 		}
 
+		if (want_reload) {
+			want_reload = 0;
+			key_generic_reload();
+		}
+
 		key = keys_getch(win[KEY].p, &count, &reg);
 		switch (key) {
 		case KEY_GENERIC_REDRAW:

src/calcurse.h

@@ -1096,6 +1096,7 @@ extern unsigned colorize;
 extern int foreground, background;
 extern enum ui_mode ui_mode;
 extern int read_only;
+extern int want_reload;
 extern const char *datefmt_str[DATE_FORMATS];
 extern int days[12];
 extern const char *monthnames[12];

src/sigs.c

@@ -86,6 +86,10 @@ static void generic_hdlr(int sig)
 		}
 		exit(EXIT_SUCCESS);
 		break;
+	case SIGUSR1:
+		want_reload = 1;
+		ungetch(KEY_RESIZE);
+		break;
 	}
 }
 
@@ -112,6 +116,7 @@ void sigs_init()
 	if (!sigs_set_hdlr(SIGCHLD, generic_hdlr)
 	    || !sigs_set_hdlr(SIGWINCH, generic_hdlr)
 	    || !sigs_set_hdlr(SIGTERM, generic_hdlr)
+	    || !sigs_set_hdlr(SIGUSR1, generic_hdlr)
 	    || !sigs_set_hdlr(SIGINT, SIG_IGN))
 		exit_calcurse(1);
 }

src/vars.c

@@ -61,6 +61,9 @@ enum ui_mode ui_mode = UI_CMDLINE;
 /* Don't save anything if this is set. */
 int read_only = 0;
 
+/* Applications can trigger a reload by sending SIGUSR1. */
+int want_reload = 0;
+
 /* Strings describing each input date format. */
 const char *datefmt_str[DATE_FORMATS];