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-rw-r--r--plugin_fifo.c318
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diff --git a/plugin_fifo.c b/plugin_fifo.c
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+/* $Id: plugin_fifo.c 1112 2010-02-14 02:47:49Z michael $
+ * $URL: https://ssl.bulix.org/svn/lcd4linux/trunk/plugin_fifo.c $
+ *
+ * Fifo plugin
+ *
+ * Copyright (C) 2008 Michael Vogt <michu@neophob.com>
+ * Copyright (C) 2010 Mattia Jona-Lasinio <mjona@users.sourceforge.net>
+ * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010 The LCD4Linux Team <lcd4linux-devel@users.sourceforge.net>
+ *
+ * This file is part of LCD4Linux.
+ *
+ * LCD4Linux is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * LCD4Linux is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+/*
+ * Configuration parameters:
+ *
+ * - FifoPath 'string' : use <string> as the fifo complete file path
+ * If absent use /tmp/lcd4linux.fifo)
+ *
+ * - FifoBufSize num : if the plugin is unable to determine the display size then
+ * set the size of the internal buffer to <num> characters
+ * otherwise use the display size (number of columns).
+ * If no display size is available and no FifoBufSize parameter
+ * is specified then arbitrarily set the internal buffer size
+ * to 80 characters.
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <signal.h>
+
+#include "debug.h"
+#include "plugin.h"
+#include "cfg.h"
+
+#ifdef WITH_DMALLOC
+#include <dmalloc.h>
+#endif
+
+#define FIFO_MAXPATH 256
+#define FIFO_DEFAULT_PATH /tmp/lcd4linux.fifo
+#define FIFO_DEFAULT_BUFSIZE 80
+#define str(s) #s
+#define string(s) str(s)
+
+struct FifoData {
+ char *path;
+ char *msg;
+ int msglen;
+ int input;
+ int created;
+};
+
+static struct FifoData fd = {
+ .path = NULL,
+ .msg = NULL,
+ .msglen = -1,
+ .input = -1,
+ .created = -1,
+};
+
+
+static int confFifo(struct FifoData *p)
+{
+ char *path, *disp, *sect, *fifosect = "Plugin:FIFO";
+ unsigned int pathlen;
+
+ info("[FIFO] Reading config file '%s'", cfg_source());
+
+ path = cfg_get(fifosect, "FifoPath", string(FIFO_DEFAULT_PATH));
+ pathlen = strlen(path);
+ if (pathlen == 0) {
+ info("[FIFO] Invalid '%s.FifoPath' entry from '%s'. "
+ "Assuming " string(FIFO_DEFAULT_PATH), fifosect, cfg_source());
+ free(path);
+ path = strdup(string(FIFO_DEFAULT_PATH));
+ pathlen = strlen(path);
+ }
+ if (pathlen > FIFO_MAXPATH) {
+ error("[FIFO] Error: Too long '%s.FifoPath' entry from '%s'. "
+ "(MAX " string(FIFO_MAXPATH) " chars)", fifosect, cfg_source());
+ free(path);
+ return (-1);
+ }
+ info("[FIFO] Read '%s.FifoPath' value is '%s'", fifosect, path);
+
+ disp = cfg_get(NULL, "Display", NULL);
+ if (disp == NULL) {
+ error("[FIFO] Error: Could not get the Display name from '%s'", cfg_source());
+ free(path);
+ return (-1);
+ }
+ if ((sect = malloc(1 + strlen("Display:") + strlen(disp))) == NULL) {
+ error("[FIFO] Error: Memory allocation failed");
+ free(disp);
+ free(path);
+ return (-1);
+ }
+ strcpy(sect, "Display:");
+ strcat(sect, disp);
+ info("[FIFO] Using display '%s'.", disp);
+ free(disp);
+
+ disp = cfg_get(sect, "Size", NULL);
+ if (disp != NULL) {
+ info("[FIFO] Getting the buffer size from '%s.Size'", sect);
+ if (sscanf(disp, "%dx%*d", &p->msglen) != 1) {
+ info("[FIFO] Could not determine the display size. " "Assuming " string(FIFO_DEFAULT_BUFSIZE));
+ p->msglen = FIFO_DEFAULT_BUFSIZE;
+ }
+ free(disp);
+ } else {
+ info("[FIFO] Could not find a '%s.Size' entry.", sect);
+ if (cfg_number(fifosect, "FifoBufSize", FIFO_DEFAULT_BUFSIZE, 0, -1, &p->msglen) > 0) {
+ info("[FIFO] Getting the buffer size from '%s.FifoBufSize'", fifosect);
+ } else {
+ info("[FIFO] Could not find a valid '%s.FifoBufSize' entry. "
+ "Assuming " string(FIFO_DEFAULT_BUFSIZE), fifosect);
+ p->msglen = FIFO_DEFAULT_BUFSIZE;
+ }
+ }
+ info("[FIFO] Read buffer size is '%d'", p->msglen);
+ free(sect);
+
+ if ((p->msg = malloc(2 + pathlen + p->msglen)) == NULL) {
+ error("[FIFO] Error: Memory allocation failed");
+ free(path);
+ return (-1);
+ }
+ p->msg[0] = 0;
+ p->path = p->msg + p->msglen + 1;
+ strcpy(p->path, path);
+ free(path);
+
+ return (0);
+}
+
+
+static int makeFifo(struct FifoData *p)
+{
+ struct stat st;
+
+ if (stat(p->path, &st) < 0) {
+ if (errno == ENOENT) {
+ if (mkfifo(p->path, 0666) == 0) {
+ p->created = 1;
+
+ return (0);
+ }
+ error("Couldn't create FIFO \"%s\": %s\n", p->path, strerror(errno));
+
+ return (-1);
+ }
+ error("Failed to stat FIFO \"%s\": %s\n", p->path, strerror(errno));
+
+ return (-1);
+ }
+
+ if (!S_ISFIFO(st.st_mode)) {
+ error("\"%s\" already exists, but is not a FIFO", p->path);
+
+ return (-1);
+ }
+
+ return (0);
+}
+
+
+static void closeFifo(struct FifoData *p)
+{
+ struct stat st;
+
+ if (p->input >= 0) {
+ close(p->input);
+ p->input = -1;
+ }
+
+ if ((p->created >= 0) && (stat(p->path, &st) == 0)) {
+ debug("Removing FIFO \"%s\"\n", p->path);
+ if (unlink(p->path) < 0) {
+ error("Could not remove FIFO \"%s\": %s\n", p->path, strerror(errno));
+
+ return;
+ }
+ p->created = -1;
+ }
+
+ if (p->msg) {
+ free(p->msg);
+ p->msg = p->path = NULL;
+ p->msglen = -1;
+ }
+}
+
+
+static int openFifo(struct FifoData *p)
+{
+ if (p->created < 0) {
+ error("Error: FIFO \"%s\" does not exist: %s\n", p->path, strerror(errno));
+
+ return (-1);
+ }
+
+ if ((p->input = open(p->path, O_RDONLY | O_NONBLOCK)) < 0) {
+ error("Could not open FIFO \"%s\" for reading: %s\n", p->path, strerror(errno));
+ closeFifo(p);
+
+ return (-1);
+ }
+
+ return (0);
+}
+
+
+static int startFifo(struct FifoData *p)
+{
+ int res;
+
+ if ((res = confFifo(p)))
+ return (res);
+
+ if ((res = makeFifo(p)))
+ return (res);
+
+ if ((res = openFifo(p)))
+ return (res);
+
+ /* ignore broken pipe */
+ signal(SIGPIPE, SIG_IGN);
+
+ return (res);
+}
+
+
+static void readFifo(struct FifoData *p)
+{
+ int bytes;
+
+ bytes = read(p->input, p->msg, p->msglen);
+ if (bytes == 0)
+ return;
+
+ if (bytes > 0) {
+ p->msg[bytes] = 0;
+ while (bytes--)
+ if (p->msg[bytes] < 0x20)
+ p->msg[bytes] = ' ';
+ } else {
+ error("[FIFO] Error %i: %s", errno, strerror(errno));
+ strcpy(p->msg, "ERROR");
+ }
+}
+
+
+static void runFifo(RESULT * result)
+{
+ static int state = 1;
+ struct FifoData *p = &fd;
+ char *s;
+
+ switch (state) {
+ case 1:
+ /* Called for the first time. Set up everything. */
+ state = startFifo(p);
+ s = "";
+ break;
+
+ case 0:
+ /* Init went fine. Now run in normal operation mode. */
+ readFifo(p);
+ s = p->msg;
+ break;
+
+ default:
+ /* There was an error somewhere in init. Do nothing. */
+ s = "ERROR";
+ break;
+ }
+
+ /* Store the result */
+ SetResult(&result, R_STRING, s);
+}
+
+
+/* plugin initialization */
+int plugin_init_fifo(void)
+{
+ AddFunction("fifo::read", 0, runFifo);
+
+ return (0);
+}
+
+
+void plugin_exit_fifo(void)
+{
+ closeFifo(&fd);
+}
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