README


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To produce a PDF manual, issue the command "make pdf" after running
`./configure'.

				 -*-

If you do not wish to build the C++ components, use:

./configure --disable-cxx

				 -*-

The `examples' subdirectory contains some examples of using libconfig
from C and C++.

				 -*-

The config file syntax changed between versions 0.8 and 0.9. In order
to implement all of the feature/enhancement requests in an elegant and
self-consistent way, the configuration grammar had to be changed in a
non-backward-compatible way. In particular, groups are now values, so
the old syntax:

group
{
  ...
}

must now be written as:

group =
{
  ...
};

Note that the trailing semicolon, which was previously optional, is
now required. Also note that a colon (':') can be used in place of the
equals sign.

				 -*-

Flex and Bison are not required in order to build this
package. However, if you modify the .l or .y files, you must have Flex
(2.5.31 or better) and Bison (2.1 or better), respectively.

				 -*-

To successfully compile using MinGW (with gcc 4.4.0 or later), it may
be necessary to modify the file "mingw32\4.4.0\libstdc++.la", changing line 11
from:

library_names='libstdc++.dll.a'

to:

library_names='libstdc++.a'

(See http://trac.osgeo.org/geos/ticket/282 for more information).
/* $Id$
 * $URL$
 *
 * plugin hddtemp
 *
 * Copyright (C) 2007 Scott Bronson <brons_lcd4linux@rinspin.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.
 *
 */

/* Example:
 * (I tried to put this info on the wiki but Akismet claimed it was spam)

	Widget SmallHDDTemp {
		class 'Text'
		expression hddtemp('/dev/hda')
		width 4
		precision 1
		align 'R'
		update tick
	}

	hddtemp home page: http://www.guzu.net/linux/hddtemp.php

	Quick Examples:
	 * hddtemp() -- return temperature of first drive (order is defined by the hddtemp daemon).
	 * hddtemp('/dev/hda') -- return temperature of /dev/hda on localhost.
	 * hddtemp('ST3400832A') -- return temperature of the drive with the given ID.
	 * hddtemp('burly', '') -- return temperature of the first drive on host burly.
	 * hddtemp('burly', 17634, '/dev/hda') -- return temperature of /dev/hda on burly connecting to the hddtemp daemon listening on port 17634.

You can find out what drives are being monitored by running
		telnet HOST PORT

i.e.

	$ telnet localhost 7634
	Trying 127.0.0.1...
	Connected to localhost.
	Escape character is '^]'.
	|/dev/hda|ST3400832A|53|C|Connection closed by foreign host.

This tells me that /dev/hda is a Seagate ST3400832A running at an awfully
toasty 53 degC.

 */


/* 
 * exported functions:
 *
 * int plugin_init_hddtemp (void)
 *  adds various functions
 * void plugin_exit_hddtemp (void)
 *
 */

#include "config.h"

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>

/* network specific includes */
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>

/* these should always be included */
#include "debug.h"
#include "plugin.h"


static int socket_open(const char *name, int port)
{
    struct sockaddr_in server;
    struct hostent *host_info;
    unsigned long addr;
    int sock;

    sock = socket(PF_INET, SOCK_STREAM, 0);
    if (sock < 0) {
	error("[hddtemp] failed to create socket: %s", strerror(errno));
	return -1;
    }

    memset(&server, 0, sizeof(server));
    if ((addr = inet_addr(name)) != INADDR_NONE) {
	memcpy((char *) &server.sin_addr, &addr, sizeof(addr));
    } else {
	host_info = gethostbyname(name);
	if (NULL == host_info) {
	    error("[hddtemp] Unknown server: %s", name);
	    return -1;
	}
	memcpy((char *) &server.sin_addr, host_info->h_addr, host_info->h_length);
    }

    server.sin_family = AF_INET;
    server.sin_port = htons(port);

    if (connect(sock, (struct sockaddr *) &server, sizeof(server)) < 0) {
	error("[hddtemp] can't connect to server %s: %s", name, strerror(errno));
	return -1;
    }

    return sock;
}


static size_t hddtemp_read(int socket, char *buffer, size_t size)
{
    size_t count = 0;
    ssize_t len;

    while (count < size) {
	len = read(socket, buffer + count, size - count);
	if (len > 0) {
	    count += len;
	} else if (len < 0) {
	    error("[hddtemp] couldn't read from socket: %s", strerror(errno));
	    return -1;
	} else {
	    break;		/* remote socket has closed */
	}
    }

    // null-terminate the string
    if (count < size) {
	buffer[count] = '\0';
    } else {
	buffer[size - 1] = '\0';
    }

    return count;
}


static int hddtemp_connect(const char *host, int port, char *buffer, size_t size)
{
    int socket, ret;

    socket = socket_open(host, port);
    if (socket < 0) {
	error("[hddtemp] Error accessing %s:%d: %s", host, port, strerror(errno));
	return -1;
    }

    ret = hddtemp_read(socket, buffer, size);
    close(socket);

    return ret;
}


/* split a value into columns and return the nth column */
/* WARNING: does return a pointer to a static string!! */
static char *split(const char *value, const int column)
{
    static char buffer[256];
    const char *p, *q, *v;
    size_t l;
    int c;

    c = 0;
    p = value;
    q = NULL;
    for (v = value; v && *v; v++) {
	if (*v == '|') {
	    if (c == column) {
		q = v;
		break;
	    } else {
		p = v + 1;
	    }
	    c++;
	}
    }

    if (c < column)
	return NULL;

    l = q ? (size_t) (q - p) : strlen(p);
    if (l >= sizeof(buffer))
	l = sizeof(buffer) - 1;
    strncpy(buffer, p, l);

    buffer[l] = '\0';
    return buffer;
}

static char *hddtemp_fetch(const char *host, int port, const char *device)
{
    char buffer[4096];
    char *key;
    int i;

    /* fetch a buffer of all hddtemps */
    if (!hddtemp_connect(host, port, buffer, sizeof(buffer))) {
	return "err";
    }

    i = 1;
    while (1) {
	key = split(buffer, i);
	if (key == NULL)
	    break;
	if (strcmp(device, key) == 0) {
	    return split(buffer, i + 2);
	}
	i += 5;
    }

    return "n/a";
}


static void my_hddtemp(RESULT * result, int argc, RESULT * argv[])
{
    char *device = "";
    int port = 7634;
    char *host = "localhost";
    char *value;

    switch (argc) {
    case 0:
	break;
    case 1:
	device = R2S(argv[0]);
	break;
    case 2:
	host = R2S(argv[0]);
	device = R2S(argv[1]);
	break;
    case 3:
	host = R2S(argv[0]);
	port = (int) R2N(argv[1]);
	device = R2S(argv[2]);
	break;
    default:
	error("hddtemp(): too many parameters");
	SetResult(&result, R_STRING, "");
	return;
    }

    value = hddtemp_fetch(host, port, device);
    SetResult(&result, R_STRING, value);
}


int plugin_init_hddtemp(void)
{
    AddFunction("hddtemp", -1, my_hddtemp);

    return 0;
}


void plugin_exit_hddtemp(void)
{
}