#include <sys/wait.h>
#include <signal.h>
#include <stdio.h>
+#include <stdarg.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>
#include "common.h"
/* Global variables for child_*() */
-i3bar_child child = { 0 };
+i3bar_child child;
/* stdin- and sigchild-watchers */
ev_io *stdin_io;
ev_child *child_sig;
/* JSON parser for stdin */
-yajl_callbacks callbacks;
yajl_handle parser;
/* JSON generator for stdout */
int child_stdin;
+/*
+ * Clears all blocks from the statusline structure in memory and frees their
+ * associated resources.
+ */
+static void clear_status_blocks() {
+ struct status_block *first;
+ while (!TAILQ_EMPTY(&statusline_head)) {
+ first = TAILQ_FIRST(&statusline_head);
+ I3STRING_FREE(first->full_text);
+ TAILQ_REMOVE(&statusline_head, first, blocks);
+ free(first);
+ }
+}
+
+/*
+ * Replaces the statusline in memory with an error message. Pass a format
+ * string and format parameters as you would in `printf'. The next time
+ * `draw_bars' is called, the error message text will be drawn on the bar in
+ * the space allocated for the statusline.
+ */
+__attribute__ ((format (printf, 1, 2))) static void set_statusline_error(const char *format, ...) {
+ clear_status_blocks();
+
+ char *message;
+ va_list args;
+ va_start(args, format);
+ vasprintf(&message, format, args);
+
+ struct status_block *err_block = scalloc(sizeof(struct status_block));
+ err_block->full_text = i3string_from_utf8("Error: ");
+ err_block->name = "error";
+ err_block->color = "red";
+ err_block->no_separator = true;
+
+ struct status_block *message_block = scalloc(sizeof(struct status_block));
+ message_block->full_text = i3string_from_utf8(message);
+ message_block->name = "error_message";
+ message_block->color = "red";
+ message_block->no_separator = true;
+
+ TAILQ_INSERT_HEAD(&statusline_head, err_block, blocks);
+ TAILQ_INSERT_TAIL(&statusline_head, message_block, blocks);
+
+ FREE(message);
+ va_end(args);
+}
+
/*
* Stop and free() the stdin- and sigchild-watchers
*
/*
* Helper function to read stdin
*
+ * Returns NULL on EOF.
+ *
*/
static unsigned char *get_buffer(ev_io *watcher, int *ret_buffer_len) {
int fd = watcher->fd;
exit(EXIT_FAILURE);
}
if (n == 0) {
- /* end of file, kill the watcher */
ELOG("stdin: received EOF\n");
- cleanup();
- draw_bars(false);
*ret_buffer_len = -1;
return NULL;
}
#else
if (status != yajl_status_ok && status != yajl_status_insufficient_data) {
#endif
- fprintf(stderr, "[i3bar] Could not parse JSON input (code %d): %.*s\n",
- status, length, input);
+ char *message = (char *)yajl_get_error(parser, 0, input, length);
+
+ /* strip the newline yajl adds to the error message */
+ if (message[strlen(message) - 1] == '\n')
+ message[strlen(message) - 1] = '\0';
+
+ fprintf(stderr, "[i3bar] Could not parse JSON input (code = %d, message = %s): %.*s\n",
+ status, message, length, input);
+
+ set_statusline_error("Could not parse JSON (%s)", message);
+ yajl_free_error(parser, (unsigned char*)message);
+ draw_bars(false);
} else if (parser_context.has_urgent) {
has_urgent = true;
}
*
*/
void child_sig_cb(struct ev_loop *loop, ev_child *watcher, int revents) {
+ int exit_status = WEXITSTATUS(watcher->rstatus);
+
ELOG("Child (pid: %d) unexpectedly exited with status %d\n",
child.pid,
- watcher->rstatus);
+ exit_status);
+
+ /* this error is most likely caused by a user giving a nonexecutable or
+ * nonexistent file, so we will handle those cases separately. */
+ if (exit_status == 126)
+ set_statusline_error("status_command is not executable (exit %d)", exit_status);
+ else if (exit_status == 127)
+ set_statusline_error("status_command not found or is missing a library dependency (exit %d)", exit_status);
+ else
+ set_statusline_error("status_command process exited unexpectedly (exit %d)", exit_status);
+
cleanup();
+ draw_bars(false);
}
void child_write_output(void) {
/*
* Start a child-process with the specified command and reroute stdin.
* We actually start a $SHELL to execute the command so we don't have to care
- * about arguments and such
+ * about arguments and such.
+ *
+ * If `command' is NULL, such as in the case when no `status_command' is given
+ * in the bar config, no child will be started.
*
*/
void start_child(char *command) {
+ if (command == NULL)
+ return;
+
/* Allocate a yajl parser which will be used to parse stdin. */
- memset(&callbacks, '\0', sizeof(yajl_callbacks));
- callbacks.yajl_map_key = stdin_map_key;
- callbacks.yajl_boolean = stdin_boolean;
- callbacks.yajl_string = stdin_string;
- callbacks.yajl_integer = stdin_integer;
- callbacks.yajl_start_array = stdin_start_array;
- callbacks.yajl_end_array = stdin_end_array;
- callbacks.yajl_start_map = stdin_start_map;
- callbacks.yajl_end_map = stdin_end_map;
+ static yajl_callbacks callbacks = {
+ .yajl_boolean = stdin_boolean,
+ .yajl_integer = stdin_integer,
+ .yajl_string = stdin_string,
+ .yajl_start_map = stdin_start_map,
+ .yajl_map_key = stdin_map_key,
+ .yajl_end_map = stdin_end_map,
+ .yajl_start_array = stdin_start_array,
+ .yajl_end_array = stdin_end_array,
+ };
#if YAJL_MAJOR < 2
yajl_parser_config parse_conf = { 0, 0 };
gen = yajl_gen_alloc(NULL);
#endif
- if (command != NULL) {
- int pipe_in[2]; /* pipe we read from */
- int pipe_out[2]; /* pipe we write to */
+ int pipe_in[2]; /* pipe we read from */
+ int pipe_out[2]; /* pipe we write to */
- if (pipe(pipe_in) == -1)
- err(EXIT_FAILURE, "pipe(pipe_in)");
- if (pipe(pipe_out) == -1)
- err(EXIT_FAILURE, "pipe(pipe_out)");
+ if (pipe(pipe_in) == -1)
+ err(EXIT_FAILURE, "pipe(pipe_in)");
+ if (pipe(pipe_out) == -1)
+ err(EXIT_FAILURE, "pipe(pipe_out)");
- child.pid = fork();
- switch (child.pid) {
- case -1:
- ELOG("Couldn't fork(): %s\n", strerror(errno));
- exit(EXIT_FAILURE);
- case 0:
- /* Child-process. Reroute streams and start shell */
+ child.pid = fork();
+ switch (child.pid) {
+ case -1:
+ ELOG("Couldn't fork(): %s\n", strerror(errno));
+ exit(EXIT_FAILURE);
+ case 0:
+ /* Child-process. Reroute streams and start shell */
- close(pipe_in[0]);
- close(pipe_out[1]);
+ close(pipe_in[0]);
+ close(pipe_out[1]);
- dup2(pipe_in[1], STDOUT_FILENO);
- dup2(pipe_out[0], STDIN_FILENO);
+ dup2(pipe_in[1], STDOUT_FILENO);
+ dup2(pipe_out[0], STDIN_FILENO);
- execl(_PATH_BSHELL, _PATH_BSHELL, "-c", command, (char*) NULL);
- return;
- default:
- /* Parent-process. Reroute streams */
+ setpgid(child.pid, 0);
+ execl(_PATH_BSHELL, _PATH_BSHELL, "-c", command, (char*) NULL);
+ return;
+ default:
+ /* Parent-process. Reroute streams */
- close(pipe_in[1]);
- close(pipe_out[0]);
+ close(pipe_in[1]);
+ close(pipe_out[0]);
- dup2(pipe_in[0], STDIN_FILENO);
- child_stdin = pipe_out[1];
+ dup2(pipe_in[0], STDIN_FILENO);
+ child_stdin = pipe_out[1];
- break;
- }
+ break;
}
/* We set O_NONBLOCK because blocking is evil in event-driven software */
void kill_child_at_exit(void) {
if (child.pid > 0) {
if (child.cont_signal > 0 && child.stopped)
- kill(child.pid, child.cont_signal);
- kill(child.pid, SIGTERM);
+ killpg(child.pid, child.cont_signal);
+ killpg(child.pid, SIGTERM);
}
}
void kill_child(void) {
if (child.pid > 0) {
if (child.cont_signal > 0 && child.stopped)
- kill(child.pid, child.cont_signal);
- kill(child.pid, SIGTERM);
+ killpg(child.pid, child.cont_signal);
+ killpg(child.pid, SIGTERM);
int status;
waitpid(child.pid, &status, 0);
cleanup();
void stop_child(void) {
if (child.stop_signal > 0 && !child.stopped) {
child.stopped = true;
- kill(child.pid, child.stop_signal);
+ killpg(child.pid, child.stop_signal);
}
}
void cont_child(void) {
if (child.cont_signal > 0 && child.stopped) {
child.stopped = false;
- kill(child.pid, child.cont_signal);
+ killpg(child.pid, child.cont_signal);
}
}