support the special interface name _first_ for ethernet/wireless

Since we have deterministic device names in Linux, these strings are a
much better default in the i3status config than "eth0" and "wlan0" (what
we used before).

1 files changed, 12 insertions, 2 deletions

diff --git a/i3status.c b/i3status.c
index fc16c49..daa2d00 100644
--- a/i3status.c
+++ b/i3status.c
@@ -576,13 +576,23 @@ int main(int argc, char *argv[]) {
 
                         CASE_SEC_TITLE("wireless") {
                                 SEC_OPEN_MAP("wireless");
-                                print_wireless_info(json_gen, buffer, title, cfg_getstr(sec, "format_up"), cfg_getstr(sec, "format_down"));
+                                const char *interface = NULL;
+                                if (strcasecmp(title, "_first_") == 0)
+                                        interface = first_eth_interface(NET_TYPE_WIRELESS);
+                                if (interface == NULL)
+                                        interface = title;
+                                print_wireless_info(json_gen, buffer, interface, cfg_getstr(sec, "format_up"), cfg_getstr(sec, "format_down"));
                                 SEC_CLOSE_MAP;
                         }
 
                         CASE_SEC_TITLE("ethernet") {
                                 SEC_OPEN_MAP("ethernet");
-                                print_eth_info(json_gen, buffer, title, cfg_getstr(sec, "format_up"), cfg_getstr(sec, "format_down"));
+                                const char *interface = NULL;
+                                if (strcasecmp(title, "_first_") == 0)
+                                        interface = first_eth_interface(NET_TYPE_ETHERNET);
+                                if (interface == NULL)
+                                        interface = title;
+                                print_eth_info(json_gen, buffer, interface, cfg_getstr(sec, "format_up"), cfg_getstr(sec, "format_down"));
                                 SEC_CLOSE_MAP;
                         }