-#define GROUP_AVERAGE 0
-#define GROUP_MAX 1
-#define GROUP_SUM 2
-#define GROUP_INCREMENTAL_SUM 3
-
-#define RRDR_OPTION_NONZERO 0x00000001 // don't output dimensions will just zero values
-#define RRDR_OPTION_REVERSED 0x00000002 // output the rows in reverse order (oldest to newest)
-#define RRDR_OPTION_ABSOLUTE 0x00000004 // values positive, for DATASOURCE_SSV before summing
-#define RRDR_OPTION_MIN2MAX 0x00000008 // when adding dimensions, use max - min, instead of sum
-#define RRDR_OPTION_SECONDS 0x00000010 // output seconds, instead of dates
-#define RRDR_OPTION_MILLISECONDS 0x00000020 // output milliseconds, instead of dates
-#define RRDR_OPTION_NULL2ZERO 0x00000040 // do not show nulls, convert them to zeros
-#define RRDR_OPTION_OBJECTSROWS 0x00000080 // each row of values should be an object, not an array
-#define RRDR_OPTION_GOOGLE_JSON 0x00000100 // comply with google JSON/JSONP specs
-#define RRDR_OPTION_JSON_WRAP 0x00000200 // wrap the response in a JSON header with info about the result
-#define RRDR_OPTION_LABEL_QUOTES 0x00000400 // in CSV output, wrap header labels in double quotes
-#define RRDR_OPTION_PERCENTAGE 0x00000800 // give values as percentage of total
-#define RRDR_OPTION_NOT_ALIGNED 0x00001000 // do not align charts for persistant timeframes
+#define ALLMETRICS_FORMAT_SHELL "shell"
+#define ALLMETRICS_FORMAT_PROMETHEUS "prometheus"
+
+#define ALLMETRICS_SHELL 1
+#define ALLMETRICS_PROMETHEUS 2
+
+#define GROUP_UNDEFINED 0
+#define GROUP_AVERAGE 1
+#define GROUP_MIN 2
+#define GROUP_MAX 3
+#define GROUP_SUM 4
+#define GROUP_INCREMENTAL_SUM 5
+
+#define RRDR_OPTION_NONZERO 0x00000001 // don't output dimensions will just zero values
+#define RRDR_OPTION_REVERSED 0x00000002 // output the rows in reverse order (oldest to newest)
+#define RRDR_OPTION_ABSOLUTE 0x00000004 // values positive, for DATASOURCE_SSV before summing
+#define RRDR_OPTION_MIN2MAX 0x00000008 // when adding dimensions, use max - min, instead of sum
+#define RRDR_OPTION_SECONDS 0x00000010 // output seconds, instead of dates
+#define RRDR_OPTION_MILLISECONDS 0x00000020 // output milliseconds, instead of dates
+#define RRDR_OPTION_NULL2ZERO 0x00000040 // do not show nulls, convert them to zeros
+#define RRDR_OPTION_OBJECTSROWS 0x00000080 // each row of values should be an object, not an array
+#define RRDR_OPTION_GOOGLE_JSON 0x00000100 // comply with google JSON/JSONP specs
+#define RRDR_OPTION_JSON_WRAP 0x00000200 // wrap the response in a JSON header with info about the result
+#define RRDR_OPTION_LABEL_QUOTES 0x00000400 // in CSV output, wrap header labels in double quotes
+#define RRDR_OPTION_PERCENTAGE 0x00000800 // give values as percentage of total
+#define RRDR_OPTION_NOT_ALIGNED 0x00001000 // do not align charts for persistant timeframes