i3
util.c
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1 #undef I3__FILE__
2 #define I3__FILE__ "util.c"
3 /*
4  * vim:ts=4:sw=4:expandtab
5  *
6  * i3 - an improved dynamic tiling window manager
7  * © 2009-2011 Michael Stapelberg and contributors (see also: LICENSE)
8  *
9  * util.c: Utility functions, which can be useful everywhere within i3 (see
10  * also libi3).
11  *
12  */
13 #include "all.h"
14 
15 #include <sys/wait.h>
16 #include <stdarg.h>
17 #if defined(__OpenBSD__)
18 #include <sys/cdefs.h>
19 #endif
20 #include <fcntl.h>
21 #include <pwd.h>
22 #include <yajl/yajl_version.h>
23 #include <libgen.h>
24 
25 #define SN_API_NOT_YET_FROZEN 1
26 #include <libsn/sn-launcher.h>
27 
28 int min(int a, int b) {
29  return (a < b ? a : b);
30 }
31 
32 int max(int a, int b) {
33  return (a > b ? a : b);
34 }
35 
36 bool rect_contains(Rect rect, uint32_t x, uint32_t y) {
37  return (x >= rect.x &&
38  x <= (rect.x + rect.width) &&
39  y >= rect.y &&
40  y <= (rect.y + rect.height));
41 }
42 
44  return (Rect){a.x + b.x,
45  a.y + b.y,
46  a.width + b.width,
47  a.height + b.height};
48 }
49 
50 /*
51  * Updates *destination with new_value and returns true if it was changed or false
52  * if it was the same
53  *
54  */
55 bool update_if_necessary(uint32_t *destination, const uint32_t new_value) {
56  uint32_t old_value = *destination;
57 
58  return ((*destination = new_value) != old_value);
59 }
60 
61 /*
62  * exec()s an i3 utility, for example the config file migration script or
63  * i3-nagbar. This function first searches $PATH for the given utility named,
64  * then falls back to the dirname() of the i3 executable path and then falls
65  * back to the dirname() of the target of /proc/self/exe (on linux).
66  *
67  * This function should be called after fork()ing.
68  *
69  * The first argument of the given argv vector will be overwritten with the
70  * executable name, so pass NULL.
71  *
72  * If the utility cannot be found in any of these locations, it exits with
73  * return code 2.
74  *
75  */
76 void exec_i3_utility(char *name, char *argv[]) {
77  /* start the migration script, search PATH first */
78  char *migratepath = name;
79  argv[0] = migratepath;
80  execvp(migratepath, argv);
81 
82  /* if the script is not in path, maybe the user installed to a strange
83  * location and runs the i3 binary with an absolute path. We use
84  * argv[0]’s dirname */
85  char *pathbuf = strdup(start_argv[0]);
86  char *dir = dirname(pathbuf);
87  sasprintf(&migratepath, "%s/%s", dir, name);
88  argv[0] = migratepath;
89  execvp(migratepath, argv);
90 
91 #if defined(__linux__)
92  /* on linux, we have one more fall-back: dirname(/proc/self/exe) */
93  char buffer[BUFSIZ];
94  if (readlink("/proc/self/exe", buffer, BUFSIZ) == -1) {
95  warn("could not read /proc/self/exe");
96  _exit(1);
97  }
98  dir = dirname(buffer);
99  sasprintf(&migratepath, "%s/%s", dir, name);
100  argv[0] = migratepath;
101  execvp(migratepath, argv);
102 #endif
103 
104  warn("Could not start %s", name);
105  _exit(2);
106 }
107 
108 /*
109  * Checks a generic cookie for errors and quits with the given message if there
110  * was an error.
111  *
112  */
113 void check_error(xcb_connection_t *conn, xcb_void_cookie_t cookie, char *err_message) {
114  xcb_generic_error_t *error = xcb_request_check(conn, cookie);
115  if (error != NULL) {
116  fprintf(stderr, "ERROR: %s (X error %d)\n", err_message , error->error_code);
117  xcb_disconnect(conn);
118  exit(-1);
119  }
120 }
121 
122 /*
123  * This function resolves ~ in pathnames.
124  * It may resolve wildcards in the first part of the path, but if no match
125  * or multiple matches are found, it just returns a copy of path as given.
126  *
127  */
128 char *resolve_tilde(const char *path) {
129  static glob_t globbuf;
130  char *head, *tail, *result;
131 
132  tail = strchr(path, '/');
133  head = strndup(path, tail ? tail - path : strlen(path));
134 
135  int res = glob(head, GLOB_TILDE, NULL, &globbuf);
136  free(head);
137  /* no match, or many wildcard matches are bad */
138  if (res == GLOB_NOMATCH || globbuf.gl_pathc != 1)
139  result = sstrdup(path);
140  else if (res != 0) {
141  die("glob() failed");
142  } else {
143  head = globbuf.gl_pathv[0];
144  result = scalloc(strlen(head) + (tail ? strlen(tail) : 0) + 1);
145  strncpy(result, head, strlen(head));
146  if (tail)
147  strncat(result, tail, strlen(tail));
148  }
149  globfree(&globbuf);
150 
151  return result;
152 }
153 
154 /*
155  * Checks if the given path exists by calling stat().
156  *
157  */
158 bool path_exists(const char *path) {
159  struct stat buf;
160  return (stat(path, &buf) == 0);
161 }
162 
163 /*
164  * Goes through the list of arguments (for exec()) and checks if the given argument
165  * is present. If not, it copies the arguments (because we cannot realloc it) and
166  * appends the given argument.
167  *
168  */
169 static char **append_argument(char **original, char *argument) {
170  int num_args;
171  for (num_args = 0; original[num_args] != NULL; num_args++) {
172  DLOG("original argument: \"%s\"\n", original[num_args]);
173  /* If the argument is already present we return the original pointer */
174  if (strcmp(original[num_args], argument) == 0)
175  return original;
176  }
177  /* Copy the original array */
178  char **result = smalloc((num_args+2) * sizeof(char*));
179  memcpy(result, original, num_args * sizeof(char*));
180  result[num_args] = argument;
181  result[num_args+1] = NULL;
182 
183  return result;
184 }
185 
186 #define y(x, ...) yajl_gen_ ## x (gen, ##__VA_ARGS__)
187 #define ystr(str) yajl_gen_string(gen, (unsigned char*)str, strlen(str))
188 
189 char *store_restart_layout(void) {
190  setlocale(LC_NUMERIC, "C");
191 #if YAJL_MAJOR >= 2
192  yajl_gen gen = yajl_gen_alloc(NULL);
193 #else
194  yajl_gen gen = yajl_gen_alloc(NULL, NULL);
195 #endif
196 
197  dump_node(gen, croot, true);
198 
199  setlocale(LC_NUMERIC, "");
200 
201  const unsigned char *payload;
202 #if YAJL_MAJOR >= 2
203  size_t length;
204 #else
205  unsigned int length;
206 #endif
207  y(get_buf, &payload, &length);
208 
209  /* create a temporary file if one hasn't been specified, or just
210  * resolve the tildes in the specified path */
211  char *filename;
212  if (config.restart_state_path == NULL) {
213  filename = get_process_filename("restart-state");
214  if (!filename)
215  return NULL;
216  } else {
218  }
219 
220  int fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC, S_IRUSR | S_IWUSR);
221  if (fd == -1) {
222  perror("open()");
223  free(filename);
224  return NULL;
225  }
226 
227  int written = 0;
228  while (written < length) {
229  int n = write(fd, payload + written, length - written);
230  /* TODO: correct error-handling */
231  if (n == -1) {
232  perror("write()");
233  free(filename);
234  close(fd);
235  return NULL;
236  }
237  if (n == 0) {
238  printf("write == 0?\n");
239  free(filename);
240  close(fd);
241  return NULL;
242  }
243  written += n;
244 #if YAJL_MAJOR >= 2
245  printf("written: %d of %zd\n", written, length);
246 #else
247  printf("written: %d of %d\n", written, length);
248 #endif
249  }
250  close(fd);
251 
252  if (length > 0) {
253  printf("layout: %.*s\n", (int)length, payload);
254  }
255 
256  y(free);
257 
258  return filename;
259 }
260 
261 /*
262  * Restart i3 in-place
263  * appends -a to argument list to disable autostart
264  *
265  */
266 void i3_restart(bool forget_layout) {
267  char *restart_filename = forget_layout ? NULL : store_restart_layout();
268 
271 
273 
274  ipc_shutdown();
275 
276  LOG("restarting \"%s\"...\n", start_argv[0]);
277  /* make sure -a is in the argument list or append it */
279 
280  /* replace -r <file> so that the layout is restored */
281  if (restart_filename != NULL) {
282  /* create the new argv */
283  int num_args;
284  for (num_args = 0; start_argv[num_args] != NULL; num_args++);
285  char **new_argv = scalloc((num_args + 3) * sizeof(char*));
286 
287  /* copy the arguments, but skip the ones we'll replace */
288  int write_index = 0;
289  bool skip_next = false;
290  for (int i = 0; i < num_args; ++i) {
291  if (skip_next)
292  skip_next = false;
293  else if (!strcmp(start_argv[i], "-r") ||
294  !strcmp(start_argv[i], "--restart"))
295  skip_next = true;
296  else
297  new_argv[write_index++] = start_argv[i];
298  }
299 
300  /* add the arguments we'll replace */
301  new_argv[write_index++] = "--restart";
302  new_argv[write_index] = restart_filename;
303 
304  /* swap the argvs */
305  start_argv = new_argv;
306  }
307 
308  execvp(start_argv[0], start_argv);
309  /* not reached */
310 }
311 
312 #if defined(__OpenBSD__) || defined(__APPLE__)
313 
314 /*
315  * Taken from FreeBSD
316  * Find the first occurrence of the byte string s in byte string l.
317  *
318  */
319 void *memmem(const void *l, size_t l_len, const void *s, size_t s_len) {
320  register char *cur, *last;
321  const char *cl = (const char *)l;
322  const char *cs = (const char *)s;
323 
324  /* we need something to compare */
325  if (l_len == 0 || s_len == 0)
326  return NULL;
327 
328  /* "s" must be smaller or equal to "l" */
329  if (l_len < s_len)
330  return NULL;
331 
332  /* special case where s_len == 1 */
333  if (s_len == 1)
334  return memchr(l, (int)*cs, l_len);
335 
336  /* the last position where its possible to find "s" in "l" */
337  last = (char *)cl + l_len - s_len;
338 
339  for (cur = (char *)cl; cur <= last; cur++)
340  if (cur[0] == cs[0] && memcmp(cur, cs, s_len) == 0)
341  return cur;
342 
343  return NULL;
344 }
345 
346 #endif
347 
348 /*
349  * Handler which will be called when we get a SIGCHLD for the nagbar, meaning
350  * it exited (or could not be started, depending on the exit code).
351  *
352  */
353 static void nagbar_exited(EV_P_ ev_child *watcher, int revents) {
354  ev_child_stop(EV_A_ watcher);
355 
356  if (!WIFEXITED(watcher->rstatus)) {
357  ELOG("ERROR: i3-nagbar did not exit normally.\n");
358  return;
359  }
360 
361  int exitcode = WEXITSTATUS(watcher->rstatus);
362  DLOG("i3-nagbar process exited with status %d\n", exitcode);
363  if (exitcode == 2) {
364  ELOG("ERROR: i3-nagbar could not be found. Is it correctly installed on your system?\n");
365  }
366 
367  *((pid_t*)watcher->data) = -1;
368 }
369 
370 /*
371  * Cleanup handler. Will be called when i3 exits. Kills i3-nagbar with signal
372  * SIGKILL (9) to make sure there are no left-over i3-nagbar processes.
373  *
374  */
375 static void nagbar_cleanup(EV_P_ ev_cleanup *watcher, int revent) {
376  pid_t *nagbar_pid = (pid_t*)watcher->data;
377  if (*nagbar_pid != -1) {
378  LOG("Sending SIGKILL (%d) to i3-nagbar with PID %d\n", SIGKILL, *nagbar_pid);
379  kill(*nagbar_pid, SIGKILL);
380  }
381 }
382 
383 /*
384  * Starts an i3-nagbar instance with the given parameters. Takes care of
385  * handling SIGCHLD and killing i3-nagbar when i3 exits.
386  *
387  * The resulting PID will be stored in *nagbar_pid and can be used with
388  * kill_nagbar() to kill the bar later on.
389  *
390  */
391 void start_nagbar(pid_t *nagbar_pid, char *argv[]) {
392  if (*nagbar_pid != -1) {
393  DLOG("i3-nagbar already running (PID %d), not starting again.\n", *nagbar_pid);
394  return;
395  }
396 
397  *nagbar_pid = fork();
398  if (*nagbar_pid == -1) {
399  warn("Could not fork()");
400  return;
401  }
402 
403  /* child */
404  if (*nagbar_pid == 0)
405  exec_i3_utility("i3-nagbar", argv);
406 
407  DLOG("Starting i3-nagbar with PID %d\n", *nagbar_pid);
408 
409  /* parent */
410  /* install a child watcher */
411  ev_child *child = smalloc(sizeof(ev_child));
412  ev_child_init(child, &nagbar_exited, *nagbar_pid, 0);
413  child->data = nagbar_pid;
414  ev_child_start(main_loop, child);
415 
416  /* install a cleanup watcher (will be called when i3 exits and i3-nagbar is
417  * still running) */
418  ev_cleanup *cleanup = smalloc(sizeof(ev_cleanup));
419  ev_cleanup_init(cleanup, nagbar_cleanup);
420  cleanup->data = nagbar_pid;
421  ev_cleanup_start(main_loop, cleanup);
422 }
423 
424 /*
425  * Kills the i3-nagbar process, if *nagbar_pid != -1.
426  *
427  * If wait_for_it is set (restarting i3), this function will waitpid(),
428  * otherwise, ev is assumed to handle it (reloading).
429  *
430  */
431 void kill_nagbar(pid_t *nagbar_pid, bool wait_for_it) {
432  if (*nagbar_pid == -1)
433  return;
434 
435  if (kill(*nagbar_pid, SIGTERM) == -1)
436  warn("kill(configerror_nagbar) failed");
437 
438  if (!wait_for_it)
439  return;
440 
441  /* When restarting, we don’t enter the ev main loop anymore and after the
442  * exec(), our old pid is no longer watched. So, ev won’t handle SIGCHLD
443  * for us and we would end up with a <defunct> process. Therefore we
444  * waitpid() here. */
445  waitpid(*nagbar_pid, NULL, 0);
446 }
bool update_if_necessary(uint32_t *destination, const uint32_t new_value)
Updates *destination with new_value and returns true if it was changed or false if it was the same...
Definition: util.c:55
#define DLOG(fmt,...)
Definition: log.h:28
#define die(...)
Definition: util.h:18
Config config
Definition: config.c:19
Stores a rectangle, for example the size of a window, the child window etc.
Definition: data.h:107
uint32_t y
Definition: data.h:109
struct Con * croot
Definition: tree.c:14
char * store_restart_layout(void)
Definition: util.c:189
const char * restart_state_path
Definition: config.h:96
static char ** append_argument(char **original, char *argument)
Definition: util.c:169
void restore_geometry(void)
Restores the geometry of each window by reparenting it to the root window at the position of its fram...
Definition: manage.c:55
char * sstrdup(const char *str)
Safe-wrapper around strdup which exits if malloc returns NULL (meaning that there is no more memory a...
static void nagbar_exited(EV_P_ ev_child *watcher, int revents)
Definition: util.c:353
void * scalloc(size_t size)
Safe-wrapper around calloc which exits if malloc returns NULL (meaning that there is no more memory a...
char * resolve_tilde(const char *path)
This function resolves ~ in pathnames.
Definition: util.c:128
xcb_connection_t * conn
Definition: main.c:42
int max(int a, int b)
Definition: util.c:32
void kill_nagbar(pid_t *nagbar_pid, bool wait_for_it)
Kills the i3-nagbar process, if *nagbar_pid != -1.
Definition: util.c:431
void exec_i3_utility(char *name, char *argv[])
exec()s an i3 utility, for example the config file migration script or i3-nagbar. ...
Definition: util.c:76
bool rect_contains(Rect rect, uint32_t x, uint32_t y)
Definition: util.c:36
int sasprintf(char **strp, const char *fmt,...)
Safe-wrapper around asprintf which exits if it returns -1 (meaning that there is no more memory avail...
Rect rect_add(Rect a, Rect b)
Definition: util.c:43
uint32_t x
Definition: data.h:30
void * smalloc(size_t size)
Safe-wrapper around malloc which exits if malloc returns NULL (meaning that there is no more memory a...
pid_t command_error_nagbar_pid
Definition: key_press.c:22
char * get_process_filename(const char *prefix)
Returns the name of a temporary file with the specified prefix.
struct ev_loop * main_loop
Definition: main.c:64
int min(int a, int b)
Definition: util.c:28
uint32_t x
Definition: data.h:108
void start_nagbar(pid_t *nagbar_pid, char *argv[])
Starts an i3-nagbar instance with the given parameters.
Definition: util.c:391
static void nagbar_cleanup(EV_P_ ev_cleanup *watcher, int revent)
Definition: util.c:375
#define LOG(fmt,...)
Definition: libi3.h:76
uint32_t height
Definition: data.h:111
void ipc_shutdown(void)
Calls shutdown() on each socket and closes it.
Definition: ipc.c:98
pid_t config_error_nagbar_pid
Definition: config_parser.c:46
bool path_exists(const char *path)
Checks if the given path exists by calling stat().
Definition: util.c:158
void i3_restart(bool forget_layout)
Restart i3 in-place appends -a to argument list to disable autostart.
Definition: util.c:266
#define ELOG(fmt,...)
Definition: libi3.h:80
#define y(x,...)
Definition: commands.c:19
void dump_node(yajl_gen gen, struct Con *con, bool inplace_restart)
Definition: ipc.c:150
void check_error(xcb_connection_t *conn, xcb_void_cookie_t cookie, char *err_message)
Checks a generic cookie for errors and quits with the given message if there was an error...
Definition: util.c:113
uint32_t width
Definition: data.h:110
char ** start_argv
Definition: main.c:40