mpd/src/myfprintf.c

/* the Music Player Daemon (MPD)
 * (c)2003-2006 by Warren Dukes (warren.dukes@gmail.com)
 * This project's homepage is: http://www.musicpd.org
 *
 * This program 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 of the License, or
 * (at your option) any later version.
 *
 * This program 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#include "myfprintf.h"
#include "interface.h"
#include "path.h"
#include "log.h"
#include "conf.h"

#include <stdarg.h>
#include <sys/param.h>
#include <unistd.h>
#include <sys/select.h>
#include <fcntl.h>
#include <string.h>
#include <errno.h>

#define BUFFER_LENGTH	MAXPATHLEN+1024

static int myfprintf_stdLogMode = 0;
static FILE *myfprintf_out;
static FILE *myfprintf_err;
static char *myfprintf_outFilename;
static char *myfprintf_errFilename;

static void blockingWrite(int fd, char *string, int len)
{
	int ret;

	while (len) {
		ret = write(fd, string, len);
		if (ret == 0)
			return;
		if (ret < 0) {
			switch (errno) {
			case EAGAIN:
			case EINTR:
				continue;
			default:
				return;
			}
		}
		len -= ret;
		string += ret;
	}
}

void myfprintfStdLogMode(FILE * out, FILE * err)
{
	myfprintf_stdLogMode = 1;
	myfprintf_out = out;
	myfprintf_err = err;
	myfprintf_outFilename = getConfigParamValue(CONF_LOG_FILE);
	myfprintf_errFilename = getConfigParamValue(CONF_ERROR_FILE);
}

void myfprintf(FILE * fp, char *format, ...)
{
	static char buffer[BUFFER_LENGTH + 1];
	va_list arglist;
	int fd = fileno(fp);

	va_start(arglist, format);
	if (fd == 1 || fd == 2) {
		if (myfprintf_stdLogMode) {
			time_t t = time(NULL);
			if (fd == 1)
				fp = myfprintf_out;
			else
				fp = myfprintf_err;
			strftime(buffer, 14, "%b %e %R", localtime(&t));
			blockingWrite(fd, buffer, strlen(buffer));
			blockingWrite(fd, " : ", 3);
		}
		vsnprintf(buffer, BUFFER_LENGTH, format, arglist);
		blockingWrite(fd, buffer, strlen(buffer));
	} else {
		int len;
		vsnprintf(buffer, BUFFER_LENGTH, format, arglist);
		len = strlen(buffer);
		if (interfacePrintWithFD(fd, buffer, len) < 0) {
			blockingWrite(fd, buffer, len);
		}
	}

	va_end(arglist);
}

int myfprintfCloseAndOpenLogFile(void)
{
	if (myfprintf_stdLogMode) {
		while (fclose(myfprintf_out) < 0 && errno == EINTR) ;
		while (fclose(myfprintf_err) < 0 && errno == EINTR) ;
		while ((myfprintf_out =
			fopen(myfprintf_outFilename, "a+")) == NULL
		       && errno == EINTR) ;
		if (!myfprintf_out) {
			ERROR("error re-opening log file: %s\n", myfprintf_out);
			return -1;
		}
		while ((myfprintf_err =
			fopen(myfprintf_errFilename, "a+")) == NULL
		       && errno == EINTR) ;
		if (!myfprintf_out) {
			ERROR("error re-opening log file: %s\n", myfprintf_out);
			return -1;
		}
		while (dup2(fileno(myfprintf_out), 1) < 0 && errno == EINTR) ;
		while (dup2(fileno(myfprintf_err), 2) < 0 && errno == EINTR) ;
	}

	return 0;
}

void myfprintfCloseLogFile(void)
{
	if (myfprintf_stdLogMode) {
		while (fclose(myfprintf_out) < 0 && errno == EINTR) ;
		while (fclose(myfprintf_err) < 0 && errno == EINTR) ;
	}
}