add libi3/ipc_connect, use it in i3-config-wizard, i3-input, i3bar

libi3/ipc_connect.c

@@ -0,0 +1,36 @@
+/*
+ * vim:ts=4:sw=4:expandtab
+ *
+ * i3 - an improved dynamic tiling window manager
+ *
+ * © 2009-2011 Michael Stapelberg and contributors
+ *
+ * See file LICENSE for license information.
+ *
+ */
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <string.h>
+#include <err.h>
+#include <stdlib.h>
+
+/*
+ * Connects to the i3 IPC socket and returns the file descriptor for the
+ * socket. die()s if anything goes wrong.
+ *
+ */
+int ipc_connect(const char *socket_path) {
+    int sockfd = socket(AF_LOCAL, SOCK_STREAM, 0);
+    if (sockfd == -1)
+        err(EXIT_FAILURE, "Could not create socket");
+
+    struct sockaddr_un addr;
+    memset(&addr, 0, sizeof(struct sockaddr_un));
+    addr.sun_family = AF_LOCAL;
+    strncpy(addr.sun_path, socket_path, sizeof(addr.sun_path) - 1);
+    if (connect(sockfd, (const struct sockaddr*)&addr, sizeof(struct sockaddr_un)) < 0)
+        err(EXIT_FAILURE, "Could not connect to i3");
+
+    return sockfd;
+}