check that paths exist before using them

include/config.h

@@ -1,7 +1,5 @@
 #pragma once
 
-#define LED_BLINK_TRIGGER_DISABLED 101
-
 /**
  * @brief parse the config file
  *
@@ -14,6 +12,11 @@ void parse_config_file(char *path);
  */
 void setup_led_formula(void);
 
+/**
+ * @brief ensure that the config paths are valid
+ */
+void check_config();
+
 extern char *battery_status_path;
 extern char *battery_power_source;
 

src/config.c

@@ -3,6 +3,7 @@
 #include <stdlib.h>
 
 #include <log.h>
+#include <sys/stat.h>
 #include <toml.h>
 #include <tinyexpr.h>
 
@@ -13,7 +14,7 @@
     if (!v) {                       \
       log_warn("missing [%s]", vn); \
     }                               \
-	} while (0);
+  } while (0)
 
 #define set_str_conf(op, tt, v) do {  \
     toml_datum_t val;                 \
@@ -21,7 +22,7 @@
     if (val.ok) {                     \
       op = val.u.s;                   \
     }                                 \
-	} while (0);
+  } while (0)
 
 #define set_int_conf(op, tt, v) do {  \
     toml_datum_t val;                 \
@@ -29,7 +30,15 @@
     if (val.ok) {                     \
       op = val.u.i;                   \
     }                                 \
-	} while (0);
+  } while (0)
+
+#define check_path(path) do {                     \
+    struct stat sb;                               \
+    if (stat(path, &sb) == -1) {                  \
+      log_fatal("path does not exist: %s", path); \
+      exit(1);                                    \
+    }                                             \
+  } while (0)
 
 static te_expr *expr;
 static double percentage;
@@ -105,5 +114,16 @@ parse_config_file(char *path)
   set_str_conf(led_blink_timing_formula, led_blink, "timing_formula");
   set_str_conf(acpi_daemon_socket_path, acpi_daemon, "socket_path");
 
+  check_config();
+
   toml_free(config);
 }
+
+void
+check_config()
+{
+  check_path(battery_status_path);
+  check_path(battery_power_source);
+  check_path(led_brightness_path);
+  check_path(acpi_daemon_socket_path);
+}

src/main.c

@@ -86,7 +86,7 @@ int
 main(int argc, char *argv[])
 {
   cag_option_context context;
-  bool plugged = plugged_in(battery_power_source);
+  bool plugged;
   char buffer[MAX_BUFLEN], *out[4], *config_path, *percent;
   int sock_fd;
   bool debug = false;
@@ -113,6 +113,10 @@ main(int argc, char *argv[])
         break;
     }
   }
+  check_config();
+
+  /* get current plugged in state */
+  plugged = plugged_in(battery_power_source);
 
   /* configure the led blinking formula */
   setup_led_formula();