202 lines
6.5 KiB
C
202 lines
6.5 KiB
C
/*
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* vim:ts=4:sw=4:expandtab
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*
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* i3 - an improved dynamic tiling window manager
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* © 2009 Michael Stapelberg and contributors (see also: LICENSE)
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*
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* i3-dump-log/main.c: Dumps the i3 SHM log to stdout.
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*
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*/
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#include <stdio.h>
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#include <stdbool.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <sys/un.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <string.h>
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#include <errno.h>
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#include <err.h>
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#include <stdint.h>
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#include <getopt.h>
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#include <limits.h>
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#include <fcntl.h>
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#include <sys/mman.h>
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#include <sys/stat.h>
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#include "libi3.h"
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#include "shmlog.h"
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#include <i3/ipc.h>
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#if !defined(__OpenBSD__)
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static uint32_t offset_next_write;
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#endif
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static uint32_t wrap_count;
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static i3_shmlog_header *header;
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static char *logbuffer,
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*walk;
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static int check_for_wrap(void) {
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if (wrap_count == header->wrap_count)
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return 0;
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/* The log wrapped. Print the remaining content and reset walk to the top
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* of the log. */
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wrap_count = header->wrap_count;
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const int len = (logbuffer + header->offset_last_wrap) - walk;
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swrite(STDOUT_FILENO, walk, len);
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walk = logbuffer + sizeof(i3_shmlog_header);
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return 1;
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}
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static void print_till_end(void) {
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check_for_wrap();
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const int len = (logbuffer + header->offset_next_write) - walk;
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swrite(STDOUT_FILENO, walk, len);
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walk += len;
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}
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int main(int argc, char *argv[]) {
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int o, option_index = 0;
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bool verbose = false;
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#if !defined(__OpenBSD__)
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bool follow = false;
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#endif
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static struct option long_options[] = {
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{"version", no_argument, 0, 'v'},
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{"verbose", no_argument, 0, 'V'},
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#if !defined(__OpenBSD__)
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{"follow", no_argument, 0, 'f'},
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#endif
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{"help", no_argument, 0, 'h'},
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{0, 0, 0, 0}
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};
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#if !defined(__OpenBSD__)
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char *options_string = "s:vfVh";
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#else
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char *options_string = "vVh";
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#endif
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while ((o = getopt_long(argc, argv, options_string, long_options, &option_index)) != -1) {
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if (o == 'v') {
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printf("i3-dump-log " I3_VERSION "\n");
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return 0;
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} else if (o == 'V') {
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verbose = true;
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#if !defined(__OpenBSD__)
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} else if (o == 'f') {
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follow = true;
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#endif
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} else if (o == 'h') {
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printf("i3-dump-log " I3_VERSION "\n");
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#if !defined(__OpenBSD__)
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printf("i3-dump-log [-fhVv]\n");
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#else
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printf("i3-dump-log [-hVv]\n");
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#endif
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return 0;
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}
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}
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char *shmname = root_atom_contents("I3_SHMLOG_PATH", NULL, 0);
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if (shmname == NULL) {
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/* Something failed. Let’s invest a little effort to find out what it
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* is. This is hugely helpful for users who want to debug i3 but are
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* not used to the procedure yet. */
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xcb_connection_t *conn;
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int screen;
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if ((conn = xcb_connect(NULL, &screen)) == NULL ||
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xcb_connection_has_error(conn)) {
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fprintf(stderr, "i3-dump-log: ERROR: Cannot connect to X11.\n\n");
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if (getenv("DISPLAY") == NULL) {
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fprintf(stderr, "Your DISPLAY environment variable is not set.\n");
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fprintf(stderr, "Are you running i3-dump-log via SSH or on a virtual console?\n");
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fprintf(stderr, "Try DISPLAY=:0 i3-dump-log\n");
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exit(1);
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}
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fprintf(stderr, "FYI: The DISPLAY environment variable is set to \"%s\".\n", getenv("DISPLAY"));
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exit(1);
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}
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if (root_atom_contents("I3_CONFIG_PATH", conn, screen) != NULL) {
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fprintf(stderr, "i3-dump-log: ERROR: i3 is running, but SHM logging is not enabled.\n\n");
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if (!is_debug_build()) {
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fprintf(stderr, "You seem to be using a release version of i3:\n %s\n\n", I3_VERSION);
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fprintf(stderr, "Release versions do not use SHM logging by default,\ntherefore i3-dump-log does not work.\n\n");
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fprintf(stderr, "Please follow this guide instead:\nhttp://i3wm.org/docs/debugging-release-version.html\n");
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exit(1);
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}
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}
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errx(EXIT_FAILURE, "Cannot get I3_SHMLOG_PATH atom contents. Is i3 running on this display?");
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}
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if (*shmname == '\0')
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errx(EXIT_FAILURE, "Cannot dump log: SHM logging is disabled in i3.");
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struct stat statbuf;
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/* NB: While we must never write, we need O_RDWR for the pthread condvar. */
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int logbuffer_shm = shm_open(shmname, O_RDWR, 0);
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if (logbuffer_shm == -1)
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err(EXIT_FAILURE, "Could not shm_open SHM segment for the i3 log (%s)", shmname);
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if (fstat(logbuffer_shm, &statbuf) != 0)
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err(EXIT_FAILURE, "stat(%s)", shmname);
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/* NB: While we must never write, we need PROT_WRITE for the pthread condvar. */
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logbuffer = mmap(NULL, statbuf.st_size, PROT_READ | PROT_WRITE, MAP_SHARED, logbuffer_shm, 0);
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if (logbuffer == MAP_FAILED)
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err(EXIT_FAILURE, "Could not mmap SHM segment for the i3 log");
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header = (i3_shmlog_header *)logbuffer;
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if (verbose)
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printf("next_write = %d, last_wrap = %d, logbuffer_size = %d, shmname = %s\n",
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header->offset_next_write, header->offset_last_wrap, header->size, shmname);
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free(shmname);
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walk = logbuffer + header->offset_next_write;
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/* We first need to print old content in case there was at least one
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* wrapping already. */
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if (*walk != '\0') {
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/* In case there was a write to the buffer already, skip the first
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* old line, it very likely is mangled. Not a problem, though, the log
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* is chatty enough to have plenty lines left. */
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while (*walk != '\n')
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walk++;
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walk++;
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}
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/* In case there was no wrapping, this is a no-op, otherwise it prints the
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* old lines. */
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wrap_count = 0;
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check_for_wrap();
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/* Then start from the beginning and print the newer lines */
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walk = logbuffer + sizeof(i3_shmlog_header);
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print_till_end();
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#if !defined(__OpenBSD__)
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if (follow) {
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/* Since pthread_cond_wait() expects a mutex, we need to provide one.
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* To not lock i3 (that’s bad, mhkay?) we just define one outside of
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* the shared memory. */
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pthread_mutex_t dummy_mutex = PTHREAD_MUTEX_INITIALIZER;
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pthread_mutex_lock(&dummy_mutex);
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while (1) {
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pthread_cond_wait(&(header->condvar), &dummy_mutex);
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/* If this was not a spurious wakeup, print the new lines. */
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if (header->offset_next_write != offset_next_write) {
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offset_next_write = header->offset_next_write;
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print_till_end();
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}
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}
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}
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#endif
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return 0;
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}
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