hexdump

一个十六进制格式化输出：

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

 void hexdump( void *data, unsigned int len )
 {
     char str[], octet[];
     int offset, i, k;
     unsigned char *buf = (unsigned char *)data;
     char dimm[] = "+------------------------------------------------------------------------------+";

     printf("%s\r\n", dimm);
     printf("| Offset  : 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F   0123456789ABCDEF |\r\n");
     printf("%s\r\n", dimm);

     for (offset = ; offset < len; offset += ) {
         sprintf( str, "| %08x: ", offset );

         for (i = ; i < ; i++) {
             if ((i + offset) < len)
                 sprintf( octet, "%02x ", buf[offset + i] );
             else
                 strcpy( octet, "   " );

             strcat( str, octet );
         }
         strcat( str, "  " );
         k = strlen( str );

         for (i = ; i < ; i++) {
             if ((i + offset) < len)
                 str[k++] = (0x20 <= (buf[offset + i]) &&  (buf[offset + i]) <= 0x7E) ? buf[offset + i] : '.';
             else
                 str[k++] = ' ';
         }

         str[k] = '\0';
         printf("%s |\r\n", str);
     }

     printf("%s\r\n", dimm);
 }

 int main( void )
 {
     int i;
     unsigned char test_buf[];

     for( i = ; i < sizeof(test_buf)/sizeof(test_buf[]); i++ )
     {
         test_buf[i] = i % ;
     }

     hexdump( test_buf, sizeof(test_buf)/sizeof(test_buf[]) );

     return ;
 }