我写的HEX转BIN的源码

#include "stdio.h"
#include "string.h"

unsigned char ChartoByte(char c)
{
    if(c-'a'>=0 ) return(c-'a'+10);
    else if(c-'A'>=0 ) return(c-'A'+10);
    else return(c-'0');
}

unsigned char Char2toByte(char* s)
{
    return (ChartoByte(*s)*16+ChartoByte(*(s+1)));
}


int main(int argc,char *argv[])
{
    FILE *fp_hex = NULL;
    FILE *fp_bin = NULL;
    char buff[64] = "" ;

    unsigned char length = 0;
    unsigned short offset = 0;  //0~65535
    unsigned char type = 0;
    unsigned char checksum = 0;
    unsigned char i = 0;

    if(argc != 2) return -1;

    printf("Input file: %s\n",argv[1]);

    if((fp_hex=fopen(argv[1],"r"))==NULL)
    {
        printf("File open error!!!\n");
        return -1;
    }

    i=strlen(argv[1]);
    argv[1][i-1]='n';
    argv[1][i-2]='i';
    argv[1][i-3]='b';
    printf("Output file: %s\n",argv[1]);

    if((fp_bin=fopen(argv[1],"wb"))==NULL)
    {
        printf("File creat error!!!\n");
        return -1;
    }

    while(1)
    {
        fgets(buff,64,fp_hex);

        if(feof(fp_hex)) break; //文件结束
        else if(buff[0] != ':') continue; //无效行
        else if( strcmp(buff,":00000001FF\n") == 0  ) break; //结束行
        else
        {
            length=Char2toByte(&buff[1]);
            offset=Char2toByte(&buff[3])*256+Char2toByte(&buff[5]);
            type=Char2toByte(&buff[7]);
            if(type==0)
            {
                fseek(fp_bin,offset,0);
                for(i=0; i<length; i++)
                    fputc(Char2toByte(&buff[9+2*i]), fp_bin);
            }

            printf("%s",buff);
        }
    }



    return(0);
}