C之：微代码——hexdump的简单实现

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#define N 16
int main(int argc,char *argv[])
{
  char filename[FILENAME_MAX];//C's max length of file name.
  FILE *Pf=NULL;
  unsigned char buffer[N]; //Use unsigned char,prevent hex overflow.
  int count,i,j;
    if(argc==1)
    {
      printf("Please tell me your file name(with path if not in the current dir):\n");
      scanf("%s",filename);
    }
    else
    {
    strcpy(filename,argv[1]);
    }
  Pf=fopen(filename,"rb");
    setvbuf(Pf,NULL,_IOFBF,1024);//Set max buffer size to 1024 bytes.
    if(Pf==0)
    {
      printf("Can't access %s!\n",filename);
      return 0;
    }
  while(feof(Pf)==0)//check the end of file.
  {
    count=fread(buffer,1,sizeof(buffer),Pf);
        printf("%08x  ",j);//number in hex.
        j+=16;
        for(i=0;i<sizeof(buffer);i++)
    {
            if(i<count)
            {
        printf("%02x ",buffer[i]);
            }
            else
            {
              printf("   ");
            }
    }
    printf("| ");
    for(i=0;i<sizeof(buffer);i++)
    {
            if(i<count)
            {
      printf("%c",isprint(buffer[i])?buffer[i]:'.');
            }
            else
            {
            printf(" ");
            }
    }
    printf("|");
    printf("\n");
  }
  fclose(Pf);
  Pf=NULL;
}

注：本例实现了“hexdump -C”的功能