Implements help & usage

src/include/ttail_init.h

@@ -18,7 +18,7 @@
 	{"verbose", no_argument, 0, 'v'},\
 	{"re-prefix", required_argument, 0, 'r'},\
 	{"re-extended", no_argument, 0, 'E'},\
-	{"re-case-insensitive", no_argument, 0, 'I'},\
+	{"re-ignore-case", no_argument, 0, 'i'},\
 	{"prefix-len", required_argument, 0, 'p'},\
 	{"date-format", required_argument, 0, 'f'},\
 	{"date-min", required_argument, 0, 'd'},\
@@ -26,8 +26,27 @@
 	{"logfile", required_argument, 0, 'l'},\
 	{0,	0,	0,	0 }\
 }
+
+#define TTAIL_OPT_HELP {\
+	{"Augment the verbosity level",NULL},\
+	{"Matched part of logline will be stripped","REGEX"},\
+	{"Interpret REGEX as an extended regular expression (specified by \
+POSIX) ",NULL},\
+	{"Ignore  case  distinctions (specified by POSIX)",NULL},\
+	{"Indicate to strip a fixed len prefix","CHAR_COUNT"},\
+	{"Set the date format (see man strptime for supported date formats"\
+,"FORMAT"},\
+	{"Start to output loglines starting from this date","DATE"},\
+	{"Not implemented","DATE"},\
+	{"Indicate logfiles","FILE"},\
+	{"",NULL},\
+	{"",NULL}\
+}
 #define TTAIL_SHORT_OPT "r:EIp:f:d:l:m:"
 
+/**<! Print help & usage */
+void usage();
+
 /**@brief Parse cli arguments and return a ttail_t
  *@param int argc
  *@param char** argv

src/main.c

@@ -12,10 +12,12 @@ int main(int argc, char **argv)
 	ttail_t *ttail;
 	if(!(ttail = ttail_init(argc, argv)))
 	{
+		usage();
 		return 1;
 	}
 	if(ttail_init_check(ttail) < 0)
 	{
+		usage();
 		ttail_free(ttail);
 		return 1;
 	}

src/ttail_init.c

@@ -1,5 +1,36 @@
 #include "ttail_init.h"
 
+void usage()
+{
+	static struct option opts[] = TTAIL_LONG_OPT;
+	static char *help[][2] = TTAIL_OPT_HELP;
+	size_t i;
+	printf("Usage : ttail -d DATE [OPTIONS]\n");
+	printf("\t\n");
+	printf("Options list\n");
+	i=0;
+	while(opts[i].name)
+	{
+		printf("\t-%c, --%s", opts[i].val, opts[i].name);
+		if(opts[i].has_arg == required_argument)
+		{
+			printf("=%s\n",
+				help[i][1]?help[i][1]:"ARG");
+		}
+		else if(opts[i].has_arg == optional_argument)
+		{
+			printf("[=%s]\n",
+				help[i][1]?help[i][1]:"ARG");
+		}
+		else
+		{
+			printf("\n");
+		}
+		printf("\t\t%s\n\n", help[i][0]);
+		i++;
+	}
+}
+
 ttail_t *ttail_init(int argc, char **argv)
 {
 	ttail_t *res;