Index: libconfig.c
==================================================================
--- libconfig.c
+++ libconfig.c
@@ -44,10 +44,11 @@
 lc_err_t lc_errno = LC_ERR_NONE;
 const char *lc_err_usererrmsg = NULL;
 const char *lc_errfile = NULL;
 int lc_optind = 0;
 int lc_errline = 0;
+char *lc_erroptname =  NULL;
 
 extern char **environ;
 
 static int lc_process_var_string(void *data, const char *value, const char **endptr) {
 	char **dataval;
@@ -84,10 +85,12 @@
 
 	return(0);
 }
 
 static int lc_process_var_hostname6(void *data, const char *value, const char **endptr) {
+	lc_errno = LC_ERR_BADFORMAT;
+
 	return(-1);
 }
 
 static int lc_process_var_ip4(uint32_t *data, const char *value, const char **endptr) {
 	uint32_t ipval = 0, curr_ipval = 0;
@@ -134,15 +137,21 @@
 
 	if (retval == 0) {
 		ipval |= curr_ipval << 24;
 		*data = ipval;
 	}
+
+	if (retval < 0) {
+		lc_errno = LC_ERR_BADFORMAT;
+	}
 
 	return(retval);
 }
 
 static int lc_process_var_ip6(void *data, const char *value, const char **endptr) {
+	lc_errno = LC_ERR_BADFORMAT;
+
 	return(-1);
 }
 
 static int lc_process_var_addr4(uint32_t *data, const char *value, const char **endptr) {
 	int lc_pv_ret;
@@ -154,10 +163,12 @@
 
 	lc_pv_ret = lc_process_var_hostname4(data, value, endptr);
 	if (lc_pv_ret == 0) {
 		return(lc_pv_ret);
 	}
+
+	lc_errno = LC_ERR_BADFORMAT;
 
 	return(-1);
 }
 
 static int lc_process_var_addr6(void *data, const char *value, const char **endptr) {
@@ -723,10 +734,11 @@
 					if (cmdargidx >= argc) {
 						fprintf(stderr, "Argument required.\n");
 						lc_errfile = local_lc_errfile;
 						lc_errline = local_lc_errline;
 						lc_errno = LC_ERR_BADFORMAT;
+						lc_erroptname = strdup(cmdarg);
 						free(usedargv);
 						free(newargv);
 						return(-1);
 					}
 					cmdoptarg = argv[cmdargidx];
@@ -734,10 +746,13 @@
 					usedargv[cmdargidx] = 1;
 				}
 
 				chkretval = lc_handle(handler, handler->var, NULL, cmdoptarg, LC_FLAGS_CMDLINE);
 				if (chkretval < 0) {
+					lc_errfile = local_lc_errfile;
+					lc_errline = local_lc_errline;
+					lc_erroptname = strdup(cmdarg);
 					retval = -1;
 				}
 
 				break;
 			}
@@ -1096,10 +1111,11 @@
 }
 
 char *lc_geterrstr(void) {
 	static char retval[512];
 	const char *errmsg = NULL;
+	const char *local_lc_errfile;
 
 	switch (lc_errno) {
 		case LC_ERR_NONE:
 			errmsg = "Success";
 			break;
@@ -1137,14 +1153,20 @@
 	if (errmsg == NULL) {
 		errmsg = "Unknown error";
 	}
 
 	if (lc_errfile == NULL) {
-		snprintf(retval, sizeof(retval), "%s:%i: %s", "<no file>", lc_errline, errmsg);
+		local_lc_errfile = "<no file>";
+	} else {
+		local_lc_errfile = lc_errfile;
+	}
+
+	if (lc_erroptname != NULL) {
+		snprintf(retval, sizeof(retval), "%s:%i: \"%s\": %s", local_lc_errfile, lc_errline, lc_erroptname, errmsg);
 	} else {
-		snprintf(retval, sizeof(retval), "%s:%i: %s", lc_errfile, lc_errline, errmsg);
+		snprintf(retval, sizeof(retval), "%s:%i: %s", local_lc_errfile, lc_errline, errmsg);
 	}
 
 	retval[sizeof(retval) - 1] = '\0';
 
 	return(retval);
 }