Add i3-msg, a sample implementation and hopefully useful utility

i3-msg/Makefile

@@ -0,0 +1,28 @@
+# Default value so one can compile i3-msg standalone
+TOPDIR=..
+
+include $(TOPDIR)/common.mk
+
+# Depend on the object files of all source-files in src/*.c and on all header files
+FILES=$(patsubst %.c,%.o,$(wildcard *.c))
+HEADERS=$(wildcard *.h)
+
+# Depend on the specific file (.c for each .o) and on all headers
+%.o: %.c ${HEADERS}
+	echo "CC $<"
+	$(CC) $(CFLAGS) -c -o $@ $<
+
+all: ${FILES}
+	echo "LINK i3-msg"
+	$(CC) -o i3-msg ${FILES} $(LDFLAGS)
+
+install: all
+	echo "INSTALL"
+	$(INSTALL) -d -m 0755 $(DESTDIR)/usr/bin
+	$(INSTALL) -m 0755 i3-msg $(DESTDIR)/usr/bin/
+
+clean:
+	rm -f *.o
+
+distclean: clean
+	rm -f i3-msg

i3-msg/main.c

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+/*
+ * vim:ts=8:expandtab
+ *
+ * i3 - an improved dynamic tiling window manager
+ *
+ * © 2009 Michael Stapelberg and contributors
+ *
+ * See file LICENSE for license information.
+ *
+ * i3-msg/main.c: Utility which sends messages to a running i3-instance using
+ * IPC via UNIX domain sockets.
+ *
+ * This serves as an example for how to send your own messages to i3.
+ * Additionally, it’s even useful sometimes :-).
+ *
+ */
+#include <ev.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <err.h>
+#include <stdint.h>
+#include <getopt.h>
+
+static void ipc_send_message(int sockfd, uint32_t message_size,
+                             uint32_t message_type, uint8_t *payload) {
+        int buffer_size = strlen("i3-ipc") + sizeof(uint32_t) + sizeof(uint32_t) + message_size;
+        char msg[buffer_size];
+        char *walk = msg;
+
+        strcpy(walk, "i3-ipc");
+        walk += strlen("i3-ipc");
+        memcpy(walk, &message_size, sizeof(uint32_t));
+        walk += sizeof(uint32_t);
+        memcpy(walk, &message_type, sizeof(uint32_t));
+        walk += sizeof(uint32_t);
+        memcpy(walk, payload, message_size);
+
+        int sent_bytes = 0;
+        int bytes_to_go = buffer_size;
+        while (sent_bytes < bytes_to_go) {
+                int n = write(sockfd, msg + sent_bytes, bytes_to_go);
+                if (n == -1)
+                        err(EXIT_FAILURE, "write() failed");
+
+                sent_bytes += n;
+                bytes_to_go -= n;
+        }
+}
+
+int main(int argc, char *argv[]) {
+        char *socket_path = "/tmp/i3-ipc.sock";
+        int o, option_index = 0;
+
+        static struct option long_options[] = {
+                {"socket", required_argument, 0, 's'},
+                {"type", required_argument, 0, 't'},
+                {"version", no_argument, 0, 'v'},
+                {"help", no_argument, 0, 'h'},
+                {0, 0, 0, 0}
+        };
+
+        char *options_string = "s:t:vh";
+
+        while ((o = getopt_long(argc, argv, options_string, long_options, &option_index)) != -1) {
+                if (o == 's') {
+                        socket_path = strdup(optarg);
+                        break;
+                } else if (o == 't') {
+                        printf("currently only commands are implemented\n");
+                } else if (o == 'v') {
+                        printf("i3-msg " I3_VERSION);
+                        return 0;
+                } else if (o == 'h') {
+                        printf("i3-msg " I3_VERSION);
+                        printf("i3-msg [-s <socket>] [-t <type>] <message>\n");
+                        return 0;
+                }
+        }
+
+        if (optind >= argc) {
+                fprintf(stderr, "Error: missing message\n");
+                fprintf(stderr, "i3-msg [-s <socket>] [-t <type>] <message>\n");
+                return 1;
+        }
+
+        int sockfd = socket(AF_LOCAL, SOCK_STREAM, 0);
+        struct sockaddr_un addr;
+        memset(&addr, 0, sizeof(struct sockaddr_un));
+        addr.sun_family = AF_LOCAL;
+        strcpy(addr.sun_path, socket_path);
+        if (connect(sockfd, &addr, sizeof(struct sockaddr_un)) < 0)
+                err(-1, "Could not connect to i3");
+
+        ipc_send_message(sockfd, strlen(argv[optind]), 0, (uint8_t*)argv[optind]);
+
+        close(sockfd);
+
+        return 0;
+}