Remove HTTP server, get ready to write basic threaded program

[matches/MCTX3420.git] / rpi / log.c

diff --git a/rpi/log.c b/rpi/log.c
index 3a8c55c..15e6618 100644 (file)
--- a/rpi/log.c
+++ b/rpi/log.c
@@ -1,16 +1,43 @@
+/**
+ * @file log.c
+ * @purpose Implement logging and error handling functions
+ */
+
+
+#include <unistd.h>
+
+// --- Custom headers --- //
 #include "log.h"
 #include "options.h"
-#include <unistd.h>
 
-static int last_len = 0;
+// --- Static variables --- //
+static char * unspecified_funct = (char*)"???";
+
+// --- Function implementations --- //
 
-void log_print(int level, char * funct, char * fmt, ...)
+/**
+ * @funct Log
+ * @purpose Print a message to stderr
+ * @param level - Specify how severe the message is.
+       If level is higher (less urgent) than the program's verbosity (see options.h) no message will be printed
+ * @param funct - String indicating the function name from which this function was called.
+       If this is NULL, Log will show the unspecified_funct string instead
+ * @param fmt - A format string
+ * @param ... - Arguments to be printed according to the format string
+ */
+void Log(int level, char * funct, char * fmt, ...)
 {
-       if (level > options.verbosity)
+       if (fmt == NULL) // sanity check
+               Fatal("Log", "Format string is NULL");
+
+       // Don't print the message unless we need to
+       if (level > options.verbosity) 
                return;
 
-       
+       if (funct == NULL)
+               funct = unspecified_funct;
 
+       // Make a human readable severity string
        char severity[BUFSIZ];
        switch (level)
        {
@@ -31,30 +58,43 @@ void log_print(int level, char * funct, char * fmt, ...)
                        break;
        }
 
-       if (funct != NULL)
-               last_len = fprintf(stderr, "%s [%d] : %s : %s - ", options.program, getpid(), severity, funct);
-       else
-       {
-               for (int i = 0; i < last_len; ++i);
-                       fprintf(stderr, " ");
-       }
+       // Print: Program name, PID, severity string, function name first
+       fprintf(stderr, "%s [%d] : %s : %s - ", options.program, getpid(), severity, funct);
+
+       // Then pass additional arguments with the format string to vfprintf for printing
        va_list va;
        va_start(va, fmt);
        vfprintf(stderr, fmt, va);
        va_end(va);
+
+       // End log messages with a newline
        fprintf(stderr, "\n");
 }
 
-void error(char * funct, char * fmt, ...)
+/**
+ * @funct Fatal
+ * @purpose Handle a Fatal error in the program by printing a message and exiting the program
+       CALLING THIS FUNCTION WILL CAUSE THE PROGAM TO EXIT
+ * @param funct - Name of the calling function
+ * @param fmt - A format string
+ * @param ... - Arguments to be printed according to the format string
+ */
+void Fatal(char * funct, char * fmt, ...)
 {
-       if (funct != NULL)
-               last_len = fprintf(stderr, "%s [%d] : Fatal error in %s - ", options.program, getpid(), funct);
-       else
+       
+       if (fmt == NULL)
        {
-               for (int i = 0; i < last_len; ++i)
-                       fprintf(stderr, " ");
-               fprintf(stderr, "Fatal - ");
+               // Fatal error in the Fatal function.
+               // (This really shouldn't happen unless someone does something insanely stupid)
+               Fatal("Fatal", "Format string is NULL");
+               return; // Should never get here
        }
+
+       if (funct == NULL)
+               funct = unspecified_funct;
+
+       fprintf(stderr, "%s [%d] : %s : FATAL - ", options.program, getpid(), funct);
+
        va_list va;
        va_start(va, fmt);
        vfprintf(stderr, fmt, va);