2 * vim:ts=4:sw=4:expandtab
4 * i3 - an improved dynamic tiling window manager
5 * © 2009-2011 Michael Stapelberg and contributors (see also: LICENSE)
7 * i3-dump-log/main.c: Dumps the i3 SHM log to stdout.
12 #include <sys/types.h>
13 #include <sys/socket.h>
31 int main(int argc, char *argv[]) {
32 int o, option_index = 0;
35 static struct option long_options[] = {
36 {"version", no_argument, 0, 'v'},
37 {"verbose", no_argument, 0, 'V'},
38 {"help", no_argument, 0, 'h'},
42 char *options_string = "s:vVh";
44 while ((o = getopt_long(argc, argv, options_string, long_options, &option_index)) != -1) {
46 printf("i3-dump-log " I3_VERSION "\n");
48 } else if (o == 'V') {
50 } else if (o == 'h') {
51 printf("i3-dump-log " I3_VERSION "\n");
52 printf("i3-dump-log [-s <socket>]\n");
57 char *shmname = root_atom_contents("I3_SHMLOG_PATH");
58 if (shmname == NULL) {
59 /* Something failed. Let’s invest a little effort to find out what it
60 * is. This is hugely helpful for users who want to debug i3 but are
61 * not used to the procedure yet. */
62 xcb_connection_t *conn;
64 if ((conn = xcb_connect(NULL, &screen)) == NULL ||
65 xcb_connection_has_error(conn)) {
66 fprintf(stderr, "i3-dump-log: ERROR: Cannot connect to X11.\n\n");
67 if (getenv("DISPLAY") == NULL) {
68 fprintf(stderr, "Your DISPLAY environment variable is not set.\n");
69 fprintf(stderr, "Are you running i3-dump-log via SSH or on a virtual console?\n");
70 fprintf(stderr, "Try DISPLAY=:0 i3-dump-log\n");
73 fprintf(stderr, "FYI: The DISPLAY environment variable is set to \"%s\".\n", getenv("DISPLAY"));
76 if (root_atom_contents("I3_CONFIG_PATH") != NULL) {
77 fprintf(stderr, "i3-dump-log: ERROR: i3 is running, but SHM logging is not enabled.\n\n");
78 if (!is_debug_build()) {
79 fprintf(stderr, "You seem to be using a release version of i3:\n %s\n\n", I3_VERSION);
80 fprintf(stderr, "Release versions do not use SHM logging by default,\ntherefore i3-dump-log does not work.\n\n");
81 fprintf(stderr, "Please follow this guide instead:\nhttp://i3wm.org/docs/debugging-release-version.html\n");
85 errx(EXIT_FAILURE, "Cannot get I3_SHMLOG_PATH atom contents. Is i3 running on this display?");
89 errx(EXIT_FAILURE, "Cannot dump log: SHM logging is disabled in i3.");
93 int logbuffer_shm = shm_open(shmname, O_RDONLY, 0);
94 if (logbuffer_shm == -1)
95 err(EXIT_FAILURE, "Could not shm_open SHM segment for the i3 log (%s)", shmname);
97 if (fstat(logbuffer_shm, &statbuf) != 0)
98 err(EXIT_FAILURE, "stat(%s)", shmname);
100 char *logbuffer = mmap(NULL, statbuf.st_size, PROT_READ, MAP_SHARED, logbuffer_shm, 0);
101 if (logbuffer == MAP_FAILED)
102 err(EXIT_FAILURE, "Could not mmap SHM segment for the i3 log");
104 i3_shmlog_header *header = (i3_shmlog_header*)logbuffer;
107 printf("next_write = %d, last_wrap = %d, logbuffer_size = %d, shmname = %s\n",
108 header->offset_next_write, header->offset_last_wrap, header->size, shmname);
110 char *walk = logbuffer + header->offset_next_write;
111 /* Skip the first line, it very likely is mangled. Not a problem, though,
112 * the log is chatty enough to have plenty lines left. */
113 while (*walk != '\0')
116 /* Print the oldest log lines. We use printf("%s") to stop on \0. */
117 while (walk < (logbuffer + header->offset_last_wrap)) {
118 chars = printf("%s", walk);
119 /* Shortcut: If there are two consecutive \0 bytes, this part of the
120 * buffer was never touched. To not call printf() for every byte of the
121 * buffer, we directly exit the loop. */
122 if (*walk == '\0' && *(walk+1) == '\0')
124 walk += (chars > 0 ? chars : 1);
127 /* Then start from the beginning and print the newer lines */
128 walk = logbuffer + sizeof(i3_shmlog_header);
129 while (walk < (logbuffer + header->offset_next_write)) {
130 chars = printf("%s", walk);
131 walk += (chars > 0 ? chars : 1);