programming-examples/java/Data_Structures/HexDump.java
2019-11-15 12:59:38 +01:00

53 lines
1.5 KiB
Java

import edu.princeton.cs.introcs.BinaryStdIn;
import edu.princeton.cs.introcs.StdOut;
/*************************************************************************
* Compilation: javac HexDump.java
* Execution: java HexDump < file
* Dependencies: BinaryStdIn.java
* Data file: http://introcs.cs.princeton.edu/stdlib/abra.txt
*
* Reads in a binary file and writes out the bytes in hex, 16 per line.
*
* % more abra.txt
* ABRACADABRA!
*
* % java HexDump 16 < abra.txt
* 41 42 52 41 43 41 44 41 42 52 41 21
* 96 bits
*
*
* Remark
* --------------------------
* - Similar to the Unix utilities od (octal dump) or hexdump (hexadecimal dump).
*
* % od -t x1 < abra.txt
* 0000000 41 42 52 41 43 41 44 41 42 52 41 21
* 0000014
*
*************************************************************************/
public class HexDump {
public static void main(String[] args) {
int BYTES_PER_LINE = 16;
if (args.length == 1) {
BYTES_PER_LINE = Integer.parseInt(args[0]);
}
int i;
for (i = 0; !BinaryStdIn.isEmpty(); i++) {
if (BYTES_PER_LINE == 0) { BinaryStdIn.readChar(); continue; }
if (i == 0) StdOut.printf("");
else if (i % BYTES_PER_LINE == 0) StdOut.printf("\n", i);
else StdOut.print(" ");
char c = BinaryStdIn.readChar();
StdOut.printf("%02x", c & 0xff);
}
if (BYTES_PER_LINE != 0) StdOut.println();
StdOut.println((i*8) + " bits");
}
}