printf.d

/*
 * Empire, the Wargame of the Century (tm)
 * Copyright (C) 1978-2004 by Walter Bright
 * All Rights Reserved
 *
 * You may use this source for personal use only. To use it commercially
 * or to distribute source or binaries of Empire, please contact
 * www.digitalmars.com.
 *
 * Written by Walter Bright.
 * This source is written in the D Programming Language.
 * See www.digitalmars.com/d/ for the D specification and compiler.
 *
 * Use entirely at your own risk. There is no warranty, expressed or implied.
 */


/* This file implements printf for GUI apps that sends the output
 * to logfile rather than stdout.
 * The file is closed after each printf, so that it is complete even
 * if the program subsequently crashes.
 */

import std.c.stdio;
import std.c.stdlib;
import std.string;
import std.file;

alias void* va_list;

const int LOG = 1;		// disable logging by setting this to 0

version (Windows)
{
    char logfile[] = r"\empire.log";
}
version (linux)
{
    char logfile[] = "/var/log/empire.log";
}

/*********************************************
 * Route printf() to a log file rather than stdio.
 */

enum Plog
{
	TOBITBUCKET,
	TOLOGFILE,
	TOSTDOUT,
};

Plog printf_logging = Plog.TOLOGFILE;

void printf_tologfile()
{
    printf_logging = Plog.TOLOGFILE;
}

void printf_tostdout()
{
    printf_logging = Plog.TOSTDOUT;
}

void printf_tobitbucket()
{
    printf_logging = Plog.TOBITBUCKET;
}

void LogfileAppend(char* buffer)
{
    if (printf_logging == Plog.TOLOGFILE)
	std.file.append(logfile, buffer[0 .. strlen(buffer)]);
    else
    {
	fputs(buffer, stdout);
	fflush(stdout);
    }
}

extern (C)
{

int VPRINTF(char* format, va_list args)
{
    if (printf_logging != Plog.TOBITBUCKET)
    {
	char buffer[128];
	char* p;
	uint psize;
	int count;

	p = buffer;
	psize = buffer.length;
	for (;;)
	{
	    version (linux)
	    {
		count = vsnprintf(p,psize,format,args);
		if (count == -1)
		    psize *= 2;
		else if (count >= cast(int)psize)
		    psize = count + 1;
		else
		    break;
	    }
	    else version (Windows)
	    {
		count = _vsnprintf(p,psize,format,args);
		if (count != -1)
		    break;
		psize *= 2;
	    }
	    else
	    {
		static assert(0);	// unsupported system
	    }
	    p = cast(char *) alloca(psize * buffer[0].sizeof);	// buffer too small, try again with larger size
	}

	LogfileAppend(p);
    }
    return 0;
}

int PRINTF(char* format, ...)
{
    int result = 0;

    if (printf_logging != Plog.TOBITBUCKET)
    {
	va_list ap;
	//va_start(ap, format);
	ap = cast(va_list)(cast(void*)format + format.sizeof);
	result = VPRINTF(format,ap);
	//va_end(ap);
    }
    return result;
}

}

void _printf_assert(char* file, uint line)
{
    PRINTF("assert fail: %s(%d)\n", file, line);
    *cast(char *)0 = 0;	// seg fault to ensure it isn't overlooked
    exit(0);
}