Fix collision between log name and daemon options

We now error out when a log name is specified at the same time as
the daemon mode option. We only allow stderr as the logging channel
in this case.

3 files changed, 10 insertions, 2 deletions

diff --git a/agent/tcf/framework/trace.c b/agent/tcf/framework/trace.c
index 5cc0dcd..bd08328 100644
--- a/agent/tcf/framework/trace.c
+++ b/agent/tcf/framework/trace.c
@@ -169,7 +169,7 @@ void open_log_file(const char * log_name) {
     if (log_name == NULL) {
         log_file = NULL;
     }
-    else if (strcmp(log_name, "-") == 0) {
+    else if (strcmp(log_name, LOG_NAME_STDERR) == 0) {
         log_file = stderr;
     }
     else if ((log_file = fopen(log_name, "a")) == NULL) {
diff --git a/agent/tcf/framework/trace.h b/agent/tcf/framework/trace.h
index 3e787a1..9cddd35 100644
--- a/agent/tcf/framework/trace.h
+++ b/agent/tcf/framework/trace.h
@@ -41,6 +41,8 @@
 #define LOG_STACK       0x2000
 #define LOG_PLUGIN      0x4000
 
+#define LOG_NAME_STDERR "-"
+
 extern int log_mode;
 
 #if ENABLE_Trace
diff --git a/agent/tcf/main/main.c b/agent/tcf/main/main.c
index ec363f7..b2c83f8 100644
--- a/agent/tcf/main/main.c
+++ b/agent/tcf/main/main.c
@@ -117,7 +117,7 @@ static BOOL CtrlHandler(DWORD ctrl) {
 static const char * help_text[] = {
     "Usage: agent [OPTION]...",
     "Start Target Communication Framework agent.",
-    "  -d               run in daemon mode",
+    "  -d               run in daemon mode (output is sent to system logger)",
 #if ENABLE_Cmdline
     "  -i               run in interactive mode",
 #endif
@@ -274,6 +274,12 @@ int main(int argc, char ** argv) {
         }
     }
 
+    if (daemon && strcmp (log_name, LOG_NAME_STDERR) != 0 && log_name != NULL) {
+        fprintf(stderr, "%s: error: can only log to stderr when in daemon "
+                "mode.\n", progname);
+        exit (1);
+    }
+
     if (daemon) become_daemon();
     open_log_file(log_name);