/* $Id$
* $URL$
*
* plugin template
*
* Copyright (C) 2008 Michael Vogt <michu@neophob.com>
* Copyright (C) 2004, 2005, 2006, 2007, 2008 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.
*
*/
/*
* Quick fifo hack for lcd4linux
*
* most code is ripped ...
*
*/
/* define the include files you need */
#include "config.h"
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <signal.h>
/* these should always be included */
#include "debug.h"
#include "plugin.h"
#include "cfg.h"
#ifdef WITH_DMALLOC
#include <dmalloc.h>
#endif
#define FIFO_BUFFER_SIZE 80
typedef struct _FifoData {
char *path;
int input;
int created;
} FifoData;
static char Section[] = "Plugin:FIFO";
static FifoData fd;
static char msg[FIFO_BUFFER_SIZE];
static char fifopath[1024];
static void configure_fifo(void)
{
char *s;
memset(fifopath, 0, 1024);
s = cfg_get(Section, "fifopath", "/tmp/lcd4linux.fifo");
if (*s == '\0') {
info("[FIFO] empty '%s.fifopath' entry from %s, assuming '/tmp/lcd4linux.fifo'", Section, cfg_source());
strcpy(fifopath, "/tmp/lcd4linux.fifo");
} else {
strcpy(fifopath, s);
info("[FIFO] read '%s.fifopath', value is '%s'", Section, fifopath);
}
free(s);
}
static void removeFifo()
{
debug("Removing FIFO \"%s\"\n", fd.path);
if (unlink(fd.path) < 0) {
error("Could not remove FIFO \"%s\": %s\n", fd.path, strerror(errno));
return;
}
fd.created = 0;
}
static void closeFifo()
{
struct stat st;
if (fd.input >= 0) {
close(fd.input);
fd.input = -1;
}
if (fd.created && (stat(fd.path, &st) == 0))
removeFifo(fd);
}
static int makeFifo()
{
if (mkfifo(fd.path, 0666) < 0) {
error("Couldn't create FIFO \"%s\": %s\n", fd.path, strerror(errno));
return -1;
}
fd.created = 1;
return 0;
}
static int checkFifo()
{
struct stat st;
if (stat(fd.path, &st) < 0) {
if (errno == ENOENT) {
/* Path doesn't exist */
return makeFifo(fd);
}
error("Failed to stat FIFO \"%s\": %s\n", fd.path, strerror(errno));
return -1;
}
if (!S_ISFIFO(st.st_mode)) {
error("\"%s\" already exists, but is not a FIFO\n", fd.path);
return -1;
}
return 0;
}
static int openFifo()
{
if (checkFifo() < 0)
return -1;
fd.input = open(fd.path, O_RDONLY | O_NONBLOCK);
if (fd.input < 0) {
error("Could not open FIFO \"%s\" for reading: %s\n", fd.path, strerror(errno));
closeFifo();
return -1;
}
return 0;
}
static void startFifo(void)
{
static int started = 0;
if (started)
return;
started = 1;
configure_fifo();
fd.path = fifopath;
fd.input = -1;
fd.created = 0;
openFifo();
/* ignore broken pipe */
signal(SIGPIPE, SIG_IGN);
memset(msg, 0, FIFO_BUFFER_SIZE);
}
static void fiforead(RESULT * result)
{
char buf[FIFO_BUFFER_SIZE];
unsigned int i;
int bytes = 1;
startFifo();
memset(buf, 0, FIFO_BUFFER_SIZE);
strcat(buf, "ERROR");
if (checkFifo() == 0) {
memset(buf, 0, FIFO_BUFFER_SIZE);
while (bytes > 0 && errno != EINTR) {
bytes = read(fd.input, buf, FIFO_BUFFER_SIZE);
}
if (bytes < 0 || (errno > 0 && errno != EAGAIN)) {
error("[FIFO] Error %i: %s", errno, strerror(errno));
} else {
if (strlen(buf) > 0) {
strcpy(msg, buf);
}
for (i = 0; i < strlen(buf); i++) {
if (msg[i] < 0x20)
msg[i] = ' ';
}
}
}
/* store result */
SetResult(&result, R_STRING, msg);
}
/* plugin initialization */
int plugin_init_fifo(void)
{
AddFunction("fifo::read", 0, fiforead);
return 0;
}
void plugin_exit_fifo(void)
{
/* close filedescriptors */
closeFifo();
}