ipv6: provide format strings for ipv6 up and ipv6 down

i3status.c

@@ -92,7 +92,8 @@ int main(int argc, char *argv[]) {
         };
 
         cfg_opt_t ipv6_opts[] = {
-                CFG_STR("format", "%ip", CFGF_NONE),
+                CFG_STR("format_up", "%ip", CFGF_NONE),
+                CFG_STR("format_down", "no IPv6", CFGF_NONE),
                 CFG_END()
         };
 
@@ -198,7 +199,7 @@ int main(int argc, char *argv[]) {
                         const char *current = cfg_getnstr(cfg, "order", j);
 
                         CASE_SEC("ipv6")
-                                print_ipv6_info(cfg_getstr(sec, "format"));
+                                print_ipv6_info(cfg_getstr(sec, "format_up"), cfg_getstr(sec, "format_down"));
 
                         CASE_SEC_TITLE("wireless")
                                 print_wireless_info(title, cfg_getstr(sec, "format_up"), cfg_getstr(sec, "format_down"));

i3status.h

@@ -58,7 +58,7 @@ void print_seperator();
 char *color(const char *colorstr);
 char *endcolor() __attribute__ ((pure));
 
-void print_ipv6_info(const char *format);
+void print_ipv6_info(const char *format_up, const char *format_down);
 void print_disk_info(const char *path, const char *format);
 void print_battery_info(int number, const char *format, bool last_full_capacity);
 void print_time(const char *format);

src/print_ipv6_addr.c

@@ -9,7 +9,7 @@
 #include <string.h>
 #include <arpa/inet.h>
 
-static bool print_sockname(struct addrinfo *addr) {
+static char * get_sockname(struct addrinfo *addr) {
         static char buf[INET6_ADDRSTRLEN+1];
         struct sockaddr_storage local;
         int ret;
@@ -17,7 +17,7 @@ static bool print_sockname(struct addrinfo *addr) {
 
         if ((fd = socket(addr->ai_family, SOCK_DGRAM, 0)) == -1) {
                 perror("socket()");
-                return false;
+                return NULL;
         }
 
         /* Since the socket was created with SOCK_DGRAM, this is
@@ -31,7 +31,7 @@ static bool print_sockname(struct addrinfo *addr) {
                  * Thus, don’t spam the user’s console but just
                  * try the next address. */
                 (void)close(fd);
-                return false;
+                return NULL;
         }
 
 
@@ -39,8 +39,7 @@ static bool print_sockname(struct addrinfo *addr) {
         if (getsockname(fd, (struct sockaddr*)&local, &local_len) == -1) {
                 perror("getsockname()");
                 (void)close(fd);
-                printf("no IPv6");
-                return true;
+                return NULL;
         }
 
         memset(buf, 0, INET6_ADDRSTRLEN + 1);
@@ -49,20 +48,18 @@ static bool print_sockname(struct addrinfo *addr) {
                                NI_NUMERICHOST)) != 0) {
                 fprintf(stderr, "getnameinfo(): %s\n", gai_strerror(ret));
                 (void)close(fd);
-                printf("no IPv6");
-                return true;
+                return NULL;
         }
 
         (void)close(fd);
-        printf("%s", buf);
-        return true;
+        return buf;
 }
 
 /*
  * Returns the IPv6 address with which you have connectivity at the moment.
- *
+ * The char * is statically allocated and mustn't be freed
  */
-static void print_ipv6_addr() {
+static char *get_ipv6_addr() {
         struct addrinfo hints;
         struct addrinfo *result, *resp;
         static struct addrinfo *cached = NULL;
@@ -70,8 +67,7 @@ static void print_ipv6_addr() {
         /* To save dns lookups (if they are not cached locally) and creating
          * sockets, we save the fd and keep it open. */
         if (cached != NULL)
-                if (print_sockname(cached))
-                        return;
+                return get_sockname(cached);
 
         memset(&hints, 0, sizeof(struct addrinfo));
         hints.ai_family = AF_INET6;
@@ -83,42 +79,47 @@ static void print_ipv6_addr() {
                 /* We don’t display the error here because most
                  * likely, there just is no connectivity.
                  * Thus, don’t spam the user’s console. */
-                printf("no IPv6");
-                return;
+                return NULL;
         }
 
         for (resp = result; resp != NULL; resp = resp->ai_next) {
-                if (!print_sockname(resp))
+                char *addr_string = get_sockname(resp);
+                if (!addr_string)
                         continue;
 
                 if ((cached = malloc(sizeof(struct addrinfo))) == NULL)
-                        return;
+                        return NULL;
                 memcpy(cached, resp, sizeof(struct addrinfo));
                 if ((cached->ai_addr = malloc(resp->ai_addrlen)) == NULL) {
                         cached = NULL;
-                        return;
+                        return NULL;
                 }
                 memcpy(cached->ai_addr, resp->ai_addr, resp->ai_addrlen);
                 freeaddrinfo(result);
-                return;
+                return addr_string;
         }
 
         freeaddrinfo(result);
-        printf("no IPv6");
+        return NULL;
 }
 
-void print_ipv6_info(const char *format) {
+void print_ipv6_info(const char *format_up, const char *format_down) {
         const char *walk;
-
-        for (walk = format; *walk != '\0'; walk++) {
-                if (*walk != '%') {
-                        putchar(*walk);
-                        continue;
-                }
-
-                if (strncmp(walk+1, "ip", strlen("ip")) == 0) {
-                        print_ipv6_addr();
-                        walk += strlen("ip");
+        char * addr_string = get_ipv6_addr();
+        
+        if (addr_string == NULL) {
+                printf("%s", format_down);
+        } else {
+                for (walk = format_up; *walk != '\0'; walk++) {
+                        if (*walk != '%') {
+                                putchar(*walk);
+                                continue;
+                        }
+                        
+                        if (strncmp(walk+1, "ip", strlen("ip")) == 0) {
+                                printf("%s", addr_string);
+                                walk += strlen("ip");
+                        }
                 }
         }
 }