Add support for auto-detetcing OS heading for progress

This patch removes the cognitive overhead of having to manually set your
OS heading, --with-heading="Foo OS vX.YY".  As of this patch, Finit by
default extracts PRETTY_NAME from /etc/os-release.  It is now possible
to also disable the heading entirely using --without-heading

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

src/finit.c

@@ -66,6 +66,7 @@ char *network   = NULL;
 char *hostname  = NULL;
 char *rcsd      = FINIT_RCSD;
 char *runparts  = NULL;
+char *osheading = NULL;
 
 uev_ctx_t *ctx  = NULL;		/* Main loop context */
 svc_t *wdog     = NULL;		/* No watchdog by default */
@@ -90,7 +91,14 @@ static void banner(void)
 	 */
 	plugin_run_hooks(HOOK_BANNER);
 
-	print_banner(INIT_HEADING);
+#ifdef INIT_OSHEADING
+	osheading = INIT_OSHEADING;
+	if (osheading) {
+		if (!osheading[0])
+			osheading = release_heading();
+		print_banner(osheading);
+	}
+#endif
 }
 
 /*

src/finit.h

@@ -115,6 +115,7 @@ extern char  *sdown;
 extern char  *network;
 extern char  *hostname;
 extern char  *runparts;
+extern char  *osheading;
 extern uev_ctx_t *ctx;
 
 #endif /* FINIT_H_ */

src/helpers.c

@@ -124,6 +124,49 @@ void show_progress(pstyle_t style)
 	progress_onoff = style;
 }
 
+/*
+ * Find PRETTY_NAME in /etc/os-release to use as heading at boot
+ * and on runlevel changes.  Fallback: "Finit vX.YY"
+ */
+char *release_heading(void)
+{
+	char *name = NULL;
+	char buf[256];
+	FILE *fp;
+
+	fp = fopen("/etc/os-release", "r");
+	if (fp) {
+		while (fgets(buf, sizeof(buf), fp)) {
+			char *ptr = &buf[12];
+
+			if (strncmp(buf, "PRETTY_NAME=", 12))
+				continue;
+
+			if (*ptr == '"' || *ptr == '\"') {
+				char *end = &ptr[strlen(ptr) - 1];
+				char q = *ptr;
+
+				while (end > ptr && isspace(*end))
+					*end-- = 0;
+
+				if (*end == q) {
+					*end = 0;
+					ptr++;
+				}
+			}
+
+			name = strdup(ptr);
+			break;
+		}
+		fclose(fp);
+	}
+
+	if (!name)
+		name = strdup(PACKAGE_NAME " v" PACKAGE_VERSION);
+
+	return name;
+}
+
 /*
  * Return screen length of string, not counting escape chars, and
  * accounting for unicode characters as only one screen byte wide

src/helpers.h

@@ -68,6 +68,8 @@ char   *strip_line      (char *line);
 void    enable_progress (int onoff);
 void    show_progress   (pstyle_t style);
 
+char   *release_heading (void);
+
 speed_t stty_parse_speed(char *baud);
 void    stty            (int fd, speed_t speed);
 

src/sm.c

@@ -150,7 +150,10 @@ restart:
 		}
 
 		_d("Setting new runlevel --> %d <-- previous %d", runlevel, prevlevel);
-		logit(LOG_CONSOLE | LOG_NOTICE, "%s, entering runlevel %d", INIT_HEADING, runlevel);
+		if (osheading)
+			logit(LOG_CONSOLE | LOG_NOTICE, "%s, entering runlevel %d", osheading, runlevel);
+		else
+			logit(LOG_CONSOLE | LOG_NOTICE, "Entering runlevel %d", runlevel);
 		runlevel_set(prevlevel, runlevel);
 
 		/* Disable login in single-user mode as well as shutdown/reboot */