trackrdrd: added usage and README

README.rst

+.. _ref-varnishd:
+
+==========
+ trackrdrd
+==========
+
+-------------------------
+Tracking Log Reader demon
+-------------------------
+
+:Author: Geoffrey Simmons
+:Date:   2012-09-23
+:Version: 0.1
+:Manual section: 3
+
+
+SYNOPSIS
+========
+
+.. include:: synopsis.txt
+
+DESCRIPTION
+===========
+
+The trackrdrd demon reads from the shared memory log of a running
+instance of Varnish and collects data relevant to tracking for the
+Lhotse project.
+
+OPTIONS
+=======
+
+.. include:: options.txt

options.txt

+    -n varnish_logfile
+        The 'varnish name' indicating the mmap'd log file used by
+        varnishd. By default, the host name is assumed (as with
+        varnishd).
+
+    -l log_file
+        Log file for status, warning, debug and error messages. If '-'
+        is specified, then log messages are written to stdout. By
+        default, syslog(3) is used for logging. Log levels correspond
+        to the 'priorities' defined by syslog(3).
+
+    -f varnishlog_bindump
+        A binary dump of the Varnish SHM log produced by 'varnishlog
+        -w'. If this option is specified, trackrdrd reads from the
+        dump instead of a live SHM log (useful for debugging and
+        replaying traffic). The options -f and -n are mutually
+        exclusive; -n is the default.
+
+    -d
+       Sets the log level to LOG_DEBUG. The default log level is
+       LOG_INFO.
+
+    -V
+       Print version and exit
+
+    -h
+       Print usage and exit

src/Makefile.am

@@ -2,7 +2,7 @@ INCLUDES = -I$(VARNISHSRC)/include -I$(VARNISHSRC)
 
 bin_PROGRAMS = trackrdrd
 
-nodist_trackrdrd_SOURCES = revision.h
+nodist_trackrdrd_SOURCES = revision.h usage.h
 
 trackrdrd_SOURCES = \
 	trackrdrd.h \
@@ -20,10 +20,11 @@ check:
 	test/regress.sh
 
 
+BUILT_SOURCES = revision.h usage.h
+MAINTAINERCLEANFILES = revision.h usage.h
+
 # Derive a revision name from the git commit
 # Adopted from Varnish include/Makefile.am
-BUILT_SOURCES = revision.h
-MAINTAINERCLEANFILES = revision.h 
 revision.h: FORCE
 	@if [ -d "$(top_srcdir)/../.git" ]; then \
 		V="$$(git show -s --pretty=format:%h)" \
@@ -51,4 +52,24 @@ revision.h: FORCE
 		) >  revision.h ; \
 		fi \
 	fi
+
+usage.h: $(top_srcdir)/synopsis.txt $(top_srcdir)/options.txt
+	( \
+	  echo '/*' ;\
+	  echo ' * NB:  This file is machine generated, DO NOT EDIT!' ;\
+	  echo ' *' ;\
+	  echo ' * Run make to regenerate' ;\
+	  echo ' *'  ;\
+	  echo ' */' ;\
+	  echo '' ;\
+	  echo 'const char *synopsis = ' \
+	) > usage.h 
+	sed -e 's/.*/\"&\\n\"/' $(top_srcdir)/synopsis.txt >> usage.h
+	( \
+	  echo ';' ;\
+	  echo 'const char *options = ' \
+	) >> usage.h
+	sed -e 's/.*/\"&\\n\"/' $(top_srcdir)/options.txt >> usage.h
+	echo ';' >> usage.h
+
 FORCE:
\ No newline at end of file

src/trackrdrd.c

@@ -56,6 +56,7 @@
 
 #include "trackrdrd.h"
 #include "revision.h"
+#include "usage.h"
 
 #define TRACK_TAGS "ReqStart,VCL_log,ReqEnd"
 #define TRACKLOG_PREFIX "track "
@@ -179,11 +180,10 @@ OSL_Track(void *priv, enum VSL_tag_e tag, unsigned fd, unsigned len,
 /*--------------------------------------------------------------------*/
 
 static void
-usage(void)
+usage(int status)
 {
-	fprintf(stderr, "usage: varnishlog "
-	    "%s [-aDV] [-o [tag regex]] [-n varnish_name] [-P file] [-w file]\n", VSL_USAGE);
-	exit(1);
+    fprintf(stderr, "Usage:\n%s\n%s\n", synopsis, options);
+    exit(status);
 }
 
 int
@@ -191,7 +191,7 @@ main(int argc, char * const *argv)
 {
 	int c;
 	int D_flag = 0, d_flag = 0;
-	const char *P_arg = NULL, *l_arg = NULL;
+	const char *P_arg = NULL, *l_arg = NULL, *n_arg = NULL, *f_arg = NULL;
 	struct vpf_fh *pfh = NULL;
 	struct VSM_data *vd;
 
@@ -208,10 +208,10 @@ main(int argc, char * const *argv)
                     break;
 		case 'V':
                     printf(PACKAGE_STRING " revision " REVISION "\n");
-                    exit(0);
+                    exit(EXIT_SUCCESS);
                 case 'n':
-                    if (VSL_Arg(vd, c, optarg) <= 0)
-                        exit(1);
+                    n_arg = optarg;
+                    break;
                 case 'l':
                     l_arg = optarg;
                     break;
@@ -219,21 +219,29 @@ main(int argc, char * const *argv)
                     d_flag = 1;
                     break;
                 case 'f':
-                    if (VSL_Arg(vd, 'r', optarg) <= 0)
-                        exit(1);
+                    f_arg = optarg;
                     break;
                 case 'h':
+                    usage(EXIT_SUCCESS);
 		default:
-                    usage();
+                    usage(EXIT_FAILURE);
 		}
 	}
 
 	if ((argc - optind) > 0)
-		usage();
+            usage(EXIT_FAILURE);
+
+        if (f_arg && n_arg)
+            usage(EXIT_FAILURE);
 
+        if (f_arg && VSL_Arg(vd, 'r', f_arg) <= 0)
+            exit(EXIT_FAILURE);
+        else if (n_arg && VSL_Arg(vd, 'n', n_arg) <= 0)
+            exit(EXIT_FAILURE);
+        
         if (LOG_Open(PACKAGE_NAME, l_arg) != 0) {
             perror(l_arg);
-            exit(1);
+            exit(EXIT_FAILURE);
         }
         if (d_flag)
             LOG_SetLevel(LOG_DEBUG);
@@ -253,14 +261,14 @@ main(int argc, char * const *argv)
         */
 	if (P_arg && (pfh = VPF_Open(P_arg, 0644, NULL)) == NULL) {
 		perror(P_arg);
-		exit(1);
+		exit(EXIT_FAILURE);
 	}
 	if (pfh != NULL)
 		VPF_Write(pfh);
 
         /* XXX: child opens and reads VSL */
 	if (VSL_Open(vd, 1))
-		exit(1);
+		exit(EXIT_FAILURE);
 
         /* Only read the VSL tags relevant to tracking */
         assert(VSL_Arg(vd, 'i', TRACK_TAGS) > 0);
@@ -277,5 +285,5 @@ main(int argc, char * const *argv)
 		VPF_Remove(pfh);
 
         LOG_Log0(LOG_INFO, "exiting");
-	exit(0);
+	exit(EXIT_SUCCESS);
 }

synopsis.txt

+  trackrdrd [-n varnish_name] [-l log_file] [-f varnishlog_bindump]
+            [-d] [-V] [-h]