556 lines
16 KiB
C
556 lines
16 KiB
C
/*
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* vim:ts=4:sw=4:expandtab
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*
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* i3bar - an xcb-based status- and ws-bar for i3
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* © 2010-2012 Axel Wagner and contributors (see also: LICENSE)
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*
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* child.c: Getting Input for the statusline
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*
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*/
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#include <stdlib.h>
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#include <unistd.h>
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#include <sys/types.h>
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#include <sys/wait.h>
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#include <signal.h>
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#include <stdio.h>
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#include <fcntl.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 <ev.h>
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#include <yajl/yajl_common.h>
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#include <yajl/yajl_parse.h>
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#include <yajl/yajl_version.h>
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#include <yajl/yajl_gen.h>
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#include "common.h"
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/* Global variables for child_*() */
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i3bar_child child = { 0 };
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/* stdin- and sigchild-watchers */
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ev_io *stdin_io;
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ev_child *child_sig;
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/* JSON parser for stdin */
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yajl_callbacks callbacks;
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yajl_handle parser;
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/* JSON generator for stdout */
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yajl_gen gen;
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typedef struct parser_ctx {
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/* True if one of the parsed blocks was urgent */
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bool has_urgent;
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/* A copy of the last JSON map key. */
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char *last_map_key;
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/* The current block. Will be filled, then copied and put into the list of
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* blocks. */
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struct status_block block;
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} parser_ctx;
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parser_ctx parser_context;
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/* The buffer statusline points to */
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struct statusline_head statusline_head = TAILQ_HEAD_INITIALIZER(statusline_head);
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char *statusline_buffer = NULL;
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int child_stdin;
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/*
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* Stop and free() the stdin- and sigchild-watchers
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*
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*/
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void cleanup(void) {
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if (stdin_io != NULL) {
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ev_io_stop(main_loop, stdin_io);
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FREE(stdin_io);
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FREE(statusline_buffer);
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/* statusline pointed to memory within statusline_buffer */
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statusline = NULL;
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}
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if (child_sig != NULL) {
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ev_child_stop(main_loop, child_sig);
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FREE(child_sig);
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}
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memset(&child, 0, sizeof(i3bar_child));
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}
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/*
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* The start of a new array is the start of a new status line, so we clear all
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* previous entries.
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*
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*/
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static int stdin_start_array(void *context) {
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struct status_block *first;
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while (!TAILQ_EMPTY(&statusline_head)) {
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first = TAILQ_FIRST(&statusline_head);
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I3STRING_FREE(first->full_text);
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FREE(first->color);
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FREE(first->name);
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FREE(first->instance);
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TAILQ_REMOVE(&statusline_head, first, blocks);
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free(first);
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}
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return 1;
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}
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/*
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* The start of a map is the start of a single block of the status line.
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*
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*/
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static int stdin_start_map(void *context) {
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parser_ctx *ctx = context;
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memset(&(ctx->block), '\0', sizeof(struct status_block));
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/* Default width of the separator block. */
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ctx->block.sep_block_width = 9;
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return 1;
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}
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#if YAJL_MAJOR >= 2
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static int stdin_map_key(void *context, const unsigned char *key, size_t len) {
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#else
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static int stdin_map_key(void *context, const unsigned char *key, unsigned int len) {
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#endif
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parser_ctx *ctx = context;
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FREE(ctx->last_map_key);
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sasprintf(&(ctx->last_map_key), "%.*s", len, key);
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return 1;
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}
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static int stdin_boolean(void *context, int val) {
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parser_ctx *ctx = context;
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if (strcasecmp(ctx->last_map_key, "urgent") == 0) {
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ctx->block.urgent = val;
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}
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if (strcasecmp(ctx->last_map_key, "separator") == 0) {
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ctx->block.no_separator = !val;
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}
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return 1;
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}
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#if YAJL_MAJOR >= 2
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static int stdin_string(void *context, const unsigned char *val, size_t len) {
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#else
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static int stdin_string(void *context, const unsigned char *val, unsigned int len) {
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#endif
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parser_ctx *ctx = context;
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if (strcasecmp(ctx->last_map_key, "full_text") == 0) {
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ctx->block.full_text = i3string_from_utf8_with_length((const char *)val, len);
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}
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if (strcasecmp(ctx->last_map_key, "color") == 0) {
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sasprintf(&(ctx->block.color), "%.*s", len, val);
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}
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if (strcasecmp(ctx->last_map_key, "align") == 0) {
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if (len == strlen("left") && !strncmp((const char*)val, "left", strlen("left"))) {
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ctx->block.align = ALIGN_LEFT;
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} else if (len == strlen("right") && !strncmp((const char*)val, "right", strlen("right"))) {
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ctx->block.align = ALIGN_RIGHT;
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} else {
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ctx->block.align = ALIGN_CENTER;
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}
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} else if (strcasecmp(ctx->last_map_key, "min_width") == 0) {
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i3String *text = i3string_from_utf8_with_length((const char *)val, len);
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ctx->block.min_width = (uint32_t)predict_text_width(text);
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i3string_free(text);
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}
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if (strcasecmp(ctx->last_map_key, "name") == 0) {
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char *copy = (char*)malloc(len+1);
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strncpy(copy, (const char *)val, len);
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copy[len] = 0;
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ctx->block.name = copy;
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}
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if (strcasecmp(ctx->last_map_key, "instance") == 0) {
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char *copy = (char*)malloc(len+1);
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strncpy(copy, (const char *)val, len);
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copy[len] = 0;
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ctx->block.instance = copy;
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}
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return 1;
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}
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#if YAJL_MAJOR >= 2
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static int stdin_integer(void *context, long long val) {
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#else
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static int stdin_integer(void *context, long val) {
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#endif
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parser_ctx *ctx = context;
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if (strcasecmp(ctx->last_map_key, "min_width") == 0) {
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ctx->block.min_width = (uint32_t)val;
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}
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if (strcasecmp(ctx->last_map_key, "separator_block_width") == 0) {
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ctx->block.sep_block_width = (uint32_t)val;
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}
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return 1;
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}
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static int stdin_end_map(void *context) {
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parser_ctx *ctx = context;
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struct status_block *new_block = smalloc(sizeof(struct status_block));
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memcpy(new_block, &(ctx->block), sizeof(struct status_block));
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/* Ensure we have a full_text set, so that when it is missing (or null),
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* i3bar doesn’t crash and the user gets an annoying message. */
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if (!new_block->full_text)
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new_block->full_text = i3string_from_utf8("SPEC VIOLATION (null)");
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if (new_block->urgent)
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ctx->has_urgent = true;
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TAILQ_INSERT_TAIL(&statusline_head, new_block, blocks);
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return 1;
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}
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static int stdin_end_array(void *context) {
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DLOG("dumping statusline:\n");
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struct status_block *current;
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TAILQ_FOREACH(current, &statusline_head, blocks) {
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DLOG("full_text = %s\n", i3string_as_utf8(current->full_text));
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DLOG("color = %s\n", current->color);
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}
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DLOG("end of dump\n");
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return 1;
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}
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/*
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* Helper function to read stdin
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*
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*/
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static unsigned char *get_buffer(ev_io *watcher, int *ret_buffer_len) {
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int fd = watcher->fd;
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int n = 0;
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int rec = 0;
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int buffer_len = STDIN_CHUNK_SIZE;
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unsigned char *buffer = smalloc(buffer_len+1);
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buffer[0] = '\0';
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while(1) {
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n = read(fd, buffer + rec, buffer_len - rec);
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if (n == -1) {
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if (errno == EAGAIN) {
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/* finish up */
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break;
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}
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ELOG("read() failed!: %s\n", strerror(errno));
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exit(EXIT_FAILURE);
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}
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if (n == 0) {
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/* end of file, kill the watcher */
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ELOG("stdin: received EOF\n");
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cleanup();
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draw_bars(false);
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*ret_buffer_len = -1;
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return NULL;
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}
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rec += n;
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if (rec == buffer_len) {
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buffer_len += STDIN_CHUNK_SIZE;
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buffer = srealloc(buffer, buffer_len);
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}
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}
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if (*buffer == '\0') {
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FREE(buffer);
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rec = -1;
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}
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*ret_buffer_len = rec;
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return buffer;
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}
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static void read_flat_input(char *buffer, int length) {
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struct status_block *first = TAILQ_FIRST(&statusline_head);
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/* Clear the old buffer if any. */
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I3STRING_FREE(first->full_text);
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/* Remove the trailing newline and terminate the string at the same
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* time. */
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if (buffer[length-1] == '\n' || buffer[length-1] == '\r')
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buffer[length-1] = '\0';
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else buffer[length] = '\0';
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first->full_text = i3string_from_utf8(buffer);
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}
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static bool read_json_input(unsigned char *input, int length) {
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yajl_status status = yajl_parse(parser, input, length);
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bool has_urgent = false;
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#if YAJL_MAJOR >= 2
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if (status != yajl_status_ok) {
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#else
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if (status != yajl_status_ok && status != yajl_status_insufficient_data) {
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#endif
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fprintf(stderr, "[i3bar] Could not parse JSON input (code %d): %.*s\n",
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status, length, input);
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} else if (parser_context.has_urgent) {
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has_urgent = true;
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}
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return has_urgent;
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}
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/*
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* Callbalk for stdin. We read a line from stdin and store the result
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* in statusline
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*
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*/
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void stdin_io_cb(struct ev_loop *loop, ev_io *watcher, int revents) {
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int rec;
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unsigned char *buffer = get_buffer(watcher, &rec);
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if (buffer == NULL)
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return;
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bool has_urgent = false;
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if (child.version > 0) {
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has_urgent = read_json_input(buffer, rec);
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} else {
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read_flat_input((char*)buffer, rec);
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}
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free(buffer);
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draw_bars(has_urgent);
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}
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/*
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* Callbalk for stdin first line. We read the first line to detect
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* whether this is JSON or plain text
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*
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*/
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void stdin_io_first_line_cb(struct ev_loop *loop, ev_io *watcher, int revents) {
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int rec;
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unsigned char *buffer = get_buffer(watcher, &rec);
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if (buffer == NULL)
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return;
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DLOG("Detecting input type based on buffer *%.*s*\n", rec, buffer);
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/* Detect whether this is JSON or plain text. */
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unsigned int consumed = 0;
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/* At the moment, we don’t care for the version. This might change
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* in the future, but for now, we just discard it. */
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parse_json_header(&child, buffer, rec, &consumed);
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if (child.version > 0) {
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/* If hide-on-modifier is set, we start of by sending the
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* child a SIGSTOP, because the bars aren't mapped at start */
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if (config.hide_on_modifier) {
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stop_child();
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}
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read_json_input(buffer + consumed, rec - consumed);
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} else {
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/* In case of plaintext, we just add a single block and change its
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* full_text pointer later. */
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struct status_block *new_block = scalloc(sizeof(struct status_block));
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TAILQ_INSERT_TAIL(&statusline_head, new_block, blocks);
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read_flat_input((char*)buffer, rec);
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}
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free(buffer);
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ev_io_stop(main_loop, stdin_io);
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ev_io_init(stdin_io, &stdin_io_cb, STDIN_FILENO, EV_READ);
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ev_io_start(main_loop, stdin_io);
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}
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/*
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* We received a sigchild, meaning, that the child-process terminated.
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* We simply free the respective data-structures and don't care for input
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* anymore
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*
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*/
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void child_sig_cb(struct ev_loop *loop, ev_child *watcher, int revents) {
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ELOG("Child (pid: %d) unexpectedly exited with status %d\n",
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child.pid,
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watcher->rstatus);
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cleanup();
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}
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void child_write_output(void) {
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if (child.click_events) {
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const unsigned char *output;
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#if YAJL_MAJOR < 2
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unsigned int size;
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#else
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size_t size;
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#endif
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yajl_gen_get_buf(gen, &output, &size);
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write(child_stdin, output, size);
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write(child_stdin, "\n", 1);
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yajl_gen_clear(gen);
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}
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}
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/*
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* Start a child-process with the specified command and reroute stdin.
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* We actually start a $SHELL to execute the command so we don't have to care
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* about arguments and such
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*
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*/
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void start_child(char *command) {
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/* Allocate a yajl parser which will be used to parse stdin. */
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memset(&callbacks, '\0', sizeof(yajl_callbacks));
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callbacks.yajl_map_key = stdin_map_key;
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callbacks.yajl_boolean = stdin_boolean;
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callbacks.yajl_string = stdin_string;
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callbacks.yajl_integer = stdin_integer;
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callbacks.yajl_start_array = stdin_start_array;
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callbacks.yajl_end_array = stdin_end_array;
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callbacks.yajl_start_map = stdin_start_map;
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callbacks.yajl_end_map = stdin_end_map;
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#if YAJL_MAJOR < 2
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yajl_parser_config parse_conf = { 0, 0 };
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parser = yajl_alloc(&callbacks, &parse_conf, NULL, (void*)&parser_context);
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gen = yajl_gen_alloc(NULL, NULL);
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#else
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parser = yajl_alloc(&callbacks, NULL, &parser_context);
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gen = yajl_gen_alloc(NULL);
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#endif
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if (command != NULL) {
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int pipe_in[2]; /* pipe we read from */
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int pipe_out[2]; /* pipe we write to */
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if (pipe(pipe_in) == -1)
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err(EXIT_FAILURE, "pipe(pipe_in)");
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if (pipe(pipe_out) == -1)
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err(EXIT_FAILURE, "pipe(pipe_out)");
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child.pid = fork();
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switch (child.pid) {
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case -1:
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ELOG("Couldn't fork(): %s\n", strerror(errno));
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exit(EXIT_FAILURE);
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case 0:
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/* Child-process. Reroute streams and start shell */
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close(pipe_in[0]);
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close(pipe_out[1]);
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dup2(pipe_in[1], STDOUT_FILENO);
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dup2(pipe_out[0], STDIN_FILENO);
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static const char *shell = NULL;
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if ((shell = getenv("SHELL")) == NULL)
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shell = "/bin/sh";
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execl(shell, shell, "-c", command, (char*) NULL);
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return;
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default:
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/* Parent-process. Reroute streams */
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close(pipe_in[1]);
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close(pipe_out[0]);
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dup2(pipe_in[0], STDIN_FILENO);
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child_stdin = pipe_out[1];
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break;
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}
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}
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/* We set O_NONBLOCK because blocking is evil in event-driven software */
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fcntl(STDIN_FILENO, F_SETFL, O_NONBLOCK);
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stdin_io = smalloc(sizeof(ev_io));
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ev_io_init(stdin_io, &stdin_io_first_line_cb, STDIN_FILENO, EV_READ);
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ev_io_start(main_loop, stdin_io);
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/* We must cleanup, if the child unexpectedly terminates */
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child_sig = smalloc(sizeof(ev_child));
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ev_child_init(child_sig, &child_sig_cb, child.pid, 0);
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ev_child_start(main_loop, child_sig);
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atexit(kill_child_at_exit);
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}
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void child_click_events_initialize(void) {
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if (!child.click_events_init) {
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yajl_gen_array_open(gen);
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child_write_output();
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child.click_events_init = true;
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}
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}
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void child_click_events_key(const char *key) {
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yajl_gen_string(gen, (const unsigned char *)key, strlen(key));
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}
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/*
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* Generates a click event, if enabled.
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*
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*/
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void send_block_clicked(int button, const char *name, const char *instance, int x, int y) {
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if (child.click_events) {
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child_click_events_initialize();
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yajl_gen_map_open(gen);
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if (name) {
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child_click_events_key("name");
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yajl_gen_string(gen, (const unsigned char *)name, strlen(name));
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}
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if (instance) {
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child_click_events_key("instance");
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yajl_gen_string(gen, (const unsigned char *)instance, strlen(instance));
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}
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child_click_events_key("button");
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yajl_gen_integer(gen, button);
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child_click_events_key("x");
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yajl_gen_integer(gen, x);
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child_click_events_key("y");
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yajl_gen_integer(gen, y);
|
||
|
||
yajl_gen_map_close(gen);
|
||
child_write_output();
|
||
}
|
||
}
|
||
|
||
/*
|
||
* kill()s the child-process (if any). Called when exit()ing.
|
||
*
|
||
*/
|
||
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);
|
||
}
|
||
}
|
||
|
||
/*
|
||
* kill()s the child-process (if existent) and closes and
|
||
* free()s the stdin- and sigchild-watchers
|
||
*
|
||
*/
|
||
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);
|
||
int status;
|
||
waitpid(child.pid, &status, 0);
|
||
cleanup();
|
||
}
|
||
}
|
||
|
||
/*
|
||
* Sends a SIGSTOP to the child-process (if existent)
|
||
*
|
||
*/
|
||
void stop_child(void) {
|
||
if (child.stop_signal > 0 && !child.stopped) {
|
||
child.stopped = true;
|
||
kill(child.pid, child.stop_signal);
|
||
}
|
||
}
|
||
|
||
/*
|
||
* Sends a SIGCONT to the child-process (if existent)
|
||
*
|
||
*/
|
||
void cont_child(void) {
|
||
if (child.cont_signal > 0 && child.stopped) {
|
||
child.stopped = false;
|
||
kill(child.pid, child.cont_signal);
|
||
}
|
||
}
|