C language implements text file and binary file format interchange

This program will create a text format of the input file ES1en1.txt, after compiling the text file can be less than 255 bytes before the character into the corresponding AscII code value of the binary representation, and stored in the output file ES4en2.txt. The base 2 file is then restored and stored in the a3.txt file.

The specific code is as follows:

#include <cstdio>
#include <stdio.h>
#include <string.h>
#define NSIZE 8

void print_2(int val2);
/*********** Text file transfer 2 Into the system **********/
void Text2Bin(const char* sIn,const char* sOut){
  char a[255];
  int count = 0;
  int ch;
  for(int j=0; j<255;j++)a[j]='\0';
  FILE* fin=fopen(sIn,"r");
  FILE* fout=fopen(sOut,"w");
  for(int i=0 ; i<=255 ; i++)fscanf(fin,"%c",&a[i]);
  for(int k=0 ; k<=254&&a[k] !='\0'; k++)
  {  
    ch = a[k];
    for(int a=7;a>=0;a--) fprintf(fout,"%d",ch>>a&1);
    //fprintf(fout,"\n");
  }
  fclose(fin);
  fclose(fout);
}
/***********2 Convert base file to text file **********/
void Bin2Text(const char* sIn,const char* sOut){
  FILE* fin=fopen(sIn,"r");
  FILE* fout=fopen(sOut,"w");
  char str[255*8];
  for(int r=0; r<255 ;r++) str[r]='\0';
  int i = 0, j = 0, iTemp = 0, flag = 0;
  int ibina[NSIZE];     
  char cRead[NSIZE];       
  char cChar;
  for(int a=0 ; a<=255 ; a++)fscanf(fin,"%c",&str[a]);
  //for(int f=0 ; f<=255 ; f++)printf("%c",str[f]);
  while(flag <= 255){
    //printf("%d",flag);
    for(int b=flag ; b>=flag && b<flag+NSIZE ; b++)
    {
      //printf("%d",b%8);
      cRead[b%8] = str[b];
      //printf("%c",cRead[b%8]);
    }
    for(i = 0; i < NSIZE; i++)
    {
      ibina[i] = (cRead[i]-'0'); 
    }
    iTemp = 1;
    cChar = 0;
    for(j = 7; j >=0 ; j--)
    {
      //printf("%c",ibina[j]);
      //printf("%d\n",cChar);
      cChar+=ibina[j]*iTemp;
      iTemp *= 2;
    }
    printf("%c",cChar);
    fprintf(fout,"%c",cChar);
    flag=flag+8;
  }
  fclose(fin);
  fclose(fout);
}

int main(){
  Text2Bin("d:\\a1.txt","d:\\a2.txt");
  Bin2Text("d:\\a2.txt","d:\\b2.txt");
  printf("\nSuccessfully converted file!\n"); 
  return 0;
}