filesearch.c

信道编解码中的turbo编解码程序

/*
*******************************************************************************
* ansi c source code
* file name:
*	FileSearch.c
* abstract:
*	provide functions to search a character or string in a file, as well as 
*	read paramaters from a file
* reference:
*
* author:
*	Wang Jiaheng	2004-09-09
* revision history:
*	Wang Jiaheng	2004-08-09	original version
*	Wang Jiaheng	2005-05-14	eliminate a bug
*******************************************************************************
*/


/*
*******************************************************************************
*                               include files
*******************************************************************************
*/
#include <stdio.h>
#include <string.h>


/*
*******************************************************************************
*                            function definition
*******************************************************************************
*/
/*
******************************************************************************* 
* description:
*	find a character in the file
* input: 
*	pf: pointer to the file
*	target: the character to be searched
* output:
*	if find, return 1; otherwise retrun 0.
* function reference : 
* author :
*	Wang Jiaheng, 2004-09-09	created
*******************************************************************************
*/
int FindChar(FILE *pf, char target)
{
	char ch;

	do
	{
		ch = fgetc(pf);
	} while( (ch != target) && (!feof(pf)) );

	if ( ch == target ) return 1;
	else return 0;
}


/*
******************************************************************************* 
* description: find a string in the file
* inputs: 
*	pf: pointer to the file
*	p_str: pointer to the string to be searched
* output:
*	if find, return 1; otherwise retrun 0.
* function reference: 
* author:
*	Wang Jiaheng, 2004-09-09	created
*******************************************************************************
*/
int FindString(FILE *pf, char *p_str)
{
	unsigned int	length;	/* length of the string */
	unsigned int	i;
	long			fpos;	/* position in the file */
	char			find;	/* indicator */

	length = strlen(p_str);
	if ( length == 0 ) return 0;

	if ( !FindChar(pf, p_str[0]) ) return 0;
	fpos = ftell(pf);
	find = 0;

	while ( (!find) && (!feof(pf)) )
	{
		find = 1;
		for (i = 1; i < length; i++)
		{
			if ( fgetc(pf) != p_str[i] )
			{
				find = 0;
				break;
			}
		}

		if ( find ) break;

		fseek(pf, fpos+1, 0);
		if ( !FindChar(pf, p_str[0]) ) return 0;
		fpos = ftell(pf);
	}

	return 1;
}


/*
******************************************************************************* 
* description:
*	change the current position to a new line
* input: 
*	pf: pointer to the file
* output:
*	if succeed, return 1; otherwise retrun 0.
* function reference: 
* author:
*	Wang Jiaheng, 2004-09-09	created
*******************************************************************************
*/
int ChangeLine(FILE *pf)
{
	if ( !FindChar(pf, 0x0a) ) return 0;

	return 1;
}


/*
******************************************************************************* 
* description:
*	read parameters from a specified file. The input file must be such a 
*	pattern below:
*	-- xxxxxxx(xx could be annotations)
*	parameter1
*	-- xxxxxxx
*	parameter2
*	......
* input: 
*	file_name: name of file
* output:
*	*p_num: number of parameters read from the file
*	para[]: array storing the parameters read from the file
* function reference: 
* author:
*	Wang Jiaheng, 2004-09-09	created
*	Wang Jiaheng, 2005-05-14	revised
*******************************************************************************
*/
int ReadFile(char file_name[], int *p_num, double para[])
{
	FILE *pf;

	pf = fopen(file_name, "r");
	if ( pf == NULL )
	{
		return 0;
	}

	*p_num = 0;
	while ( FindString(pf, "--") )
	{
		if ( !ChangeLine(pf) ) break;
		fscanf(pf, "%lf", &para[(*p_num)]);
		(*p_num)++;
	}

	fclose(pf);
	return 1;
}