Less confusing error message when realpath() fails.

[cubemap] / main.cpp

diff --git a/main.cpp b/main.cpp
index b927237529034ec01984150434ad9d713886c5b7..8430c207134ee026bb9fcb45713eea70ee0c746e 100644 (file)
--- a/main.cpp
+++ b/main.cpp
@@ -1,6 +1,7 @@
 #include <assert.h>
 #include <errno.h>
 #include <getopt.h>
+#include <limits.h>
 #include <signal.h>
 #include <stddef.h>
 #include <stdio.h>
@@ -269,13 +270,37 @@ int main(int argc, char **argv)
                config_filename = argv[optind++];
        }
 
+       // Canonicalize argv[0] and config_filename.
+       char argv0_canon[PATH_MAX];
+       char config_filename_canon[PATH_MAX];
+
+       if (realpath(argv[0], argv0_canon) == NULL) {
+               log_perror(argv[0]);
+               exit(1);
+       }
+       if (realpath(config_filename.c_str(), config_filename_canon) == NULL) {
+               log_perror(config_filename.c_str());
+               exit(1);
+       }
+
+       // Now parse the configuration file.
        Config config;
-       if (!parse_config(config_filename, &config)) {
+       if (!parse_config(config_filename_canon, &config)) {
                exit(1);
        }
        if (test_config) {
                exit(0);
        }
+       
+       // Ideally we'd like to daemonize only when we've started up all threads etc.,
+       // but daemon() forks, which is not good in multithreaded software, so we'll
+       // have to do it here.
+       if (config.daemonize) {
+               if (daemon(0, 0) == -1) {
+                       log_perror("daemon");
+                       exit(1);
+               }
+       }
 
 start:
        // Open logs as soon as possible.
@@ -402,7 +427,7 @@ start:
        }
 
        // OK, so the signal was SIGHUP. Check that the new config is okay, then exec the new binary.
-       if (!dry_run_config(argv[0], config_filename)) {
+       if (!dry_run_config(argv0_canon, config_filename_canon)) {
                open_logs(config.log_destinations);
                log(ERROR, "%s --test-config failed. Restarting old version instead of new.", argv[0]);
                hupped = false;
@@ -414,10 +439,10 @@ start:
        sprintf(buf, "%d", state_fd);
 
        for ( ;; ) {
-               execlp(argv[0], argv[0], config_filename.c_str(), "--state", buf, NULL);
+               execlp(argv0_canon, argv0_canon, config_filename_canon, "--state", buf, NULL);
                open_logs(config.log_destinations);
                log_perror("execlp");
-               log(ERROR, "re-exec of %s failed. Waiting 0.2 seconds and trying again...", argv[0]);
+               log(ERROR, "re-exec of %s failed. Waiting 0.2 seconds and trying again...", argv0_canon);
                shut_down_logging();
                usleep(200000);
        }