/*
	AccessLog.c : Count access CGI.

	Programed by Kaburaya Seiden.
	http://www2.justnet.ne.jp/~kabstudio/
	kab-studio@multimedia.design.co.jp

	This program is "Copyleft".
*/


/* If you compile in DEBUG mode, set 1.*/
/* else(Release mode), set 0 */
#define MODE_DEBUG 0


/* If you use "flock", set 1 */
/* If you use "lockf", set 0 */
#define MODE_FLOCK 1


#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#if MODE_FLOCK
#include <sys/file.h>
#else
#include <unistd.h>
#endif


#define MAX_URL_LEN	257
#define LOG_FILE_NAME	"./AccessLog.txt"
#define IMG_DEFAULT	"./TPDot.gif"
#define START_COUNT	"000001"


/*				programs				*/

int Locking( p_pfLogFile )
FILE	*p_pfLogFile;
{
	int iFileNo, iLockRes;

	iFileNo = fileno( p_pfLogFile );

#if MODE_FLOCK
	iLockRes = flock( iFileNo, LOCK_EX );
#else
	lseek( iFileNo, 0L, 0 );
	iLockRes = lockf( iFileNo, F_LOCK, 0L );
#endif

	if( iLockRes == -1 )
		return 0;

	return 1;
}


int Unlocking( p_pfLogFile )
FILE	*p_pfLogFile;
{
	int iFileNo, iLockRes;
	
	iFileNo = fileno( p_pfLogFile );
	
#if MODE_FLOCK
	iLockRes = flock( iFileNo, LOCK_UN );
#else
	lseek( iFileNo, 0L, 0 );
	iLockRes = lockf( iFileNo, F_ULOCK, 0L );
#endif

	if( iLockRes == -1 )
		return 0;

	return 1;
}


long UrlSearch( p_pchRetCount, p_pchUrl, p_pfLogFile )
char	*p_pchRetCount;
char	*p_pchUrl;
FILE	*p_pfLogFile;
{
	int		iScanRes;
	long	lFilePos;
	char	chUrl[MAX_URL_LEN];

	rewind( p_pfLogFile );
	do
	{
		iScanRes = fscanf( p_pfLogFile, "%s", chUrl );	/* Read. */
		if( strcmp( chUrl, p_pchUrl ) == 0 )		/* Hit!! */
		{
			lFilePos = ftell( p_pfLogFile );	/* Return file POINTER position */
			iScanRes = fscanf( p_pfLogFile, "%s", p_pchRetCount ); /* Get count. */
			return lFilePos;
		}
	}while( iScanRes != EOF );

	return 0L;
}


void IncTextCount( p_pchRetCount )
char	*p_pchRetCount;
{
	int		iCarryUp, iLen, iF1;
	char	chChar;

	iCarryUp = 1;
	iLen = strlen( p_pchRetCount );

	for( iF1 = iLen - 1; 0 <= iF1; iF1-- )
	{
		chChar = p_pchRetCount[iF1];
		if( iCarryUp == 1 && chChar == '9' )
		{
			p_pchRetCount[iF1] = '0';
			iCarryUp = 1;
		}
		else
		{
			p_pchRetCount[iF1] += iCarryUp;
			iCarryUp = 0;
		}
	}

	return;
}


void IncCount( p_pchLogFile, p_pchUrl )
char *p_pchLogFile;
char *p_pchUrl;
{
	int	iLockRes;
	long	lFilePos;
	char	chCount[12];
	FILE	*pfLogFile;

	pfLogFile = fopen( p_pchLogFile, "r+" );
	if( pfLogFile == NULL )
		return;

	iLockRes = Locking( pfLogFile );
	if( iLockRes == -1 )
	{
		fclose( pfLogFile );
		return;
	}
	/* Lock Start!! */

	lFilePos = UrlSearch( chCount, p_pchUrl, pfLogFile );	/* Search same name. */

	if( lFilePos == 0L )		/* New Url */
	{
		fseek( pfLogFile, 0L, 2 );	/* Go to EOF. */
		fprintf( pfLogFile, "%s %s\n", p_pchUrl, START_COUNT );	/* Write log. */
	}
	else
	{
		IncTextCount( chCount );	/* Increment count. */
		fseek( pfLogFile, lFilePos, 0 );	/* Set postion. */
		fprintf( pfLogFile, " %s\n", chCount );	/* Write log. */
	}

	/* Lock End */
	Unlocking( pfLogFile );

	return;
}



void DelYen( p_pchRet, p_pchArg )
char *p_pchRet;
char *p_pchArg;
{
	int	iChar, iPArg, iPRet;

	iPArg = 0;
	iPRet = 0;

	do
	{
		iChar = p_pchArg[iPArg];
		if( iChar != '\\' )
		{
			p_pchRet[iPRet] = iChar;
			++iPRet;
		}
		++iPArg;
	}while( iChar != '\0' );

	return;
}



int WriteImg( p_pchFile )
char	*p_pchFile;
{
	int	iChar, iScanRes;
	FILE	*pfImg;

	printf( "Content-type: image/gif\n\n" );

	pfImg = fopen( p_pchFile, "rb" ); /* Read Only, Bynary mode */
	if( pfImg == NULL )
		return 0;

	rewind( pfImg );	/* Go to Top */
	while( !feof( pfImg ) )
		putchar( fgetc( pfImg ) );	/* Output */
	fclose( pfImg );

	return 1;
}



int main( argc, argv )
int argc;
char *argv[];
{
	char chPara[MAX_URL_LEN];

	/* display dot */
	WriteImg( IMG_DEFAULT );

	if( argc != 2 ) 
		exit( 1 );

	DelYen( chPara, argv[1] );

	/*  Count */
	IncCount( LOG_FILE_NAME, chPara );

	exit( 0 );
}