Method: String#hexdump

Defined in:
lib/pentex/core.rb

#hexdump(opts = {}) ⇒ Object

shows (binary) string in a readable format.
Options:

:bytes => 16;       the maximum number of bytes per line
:offset => 0;       not supported yet
:max_bytes => 0;    the max number of bytes to be processed
:chunksize => 8;    splitted by "-"
:range => nil;      use this to define the range to be displayes, e.g. "(10..20)" must be a Range-Object!
:format => :simple; this is the only format supported yet
:max_lines => 40;   number of lines before stopping output


Example 1:

>> "\x02:this is a string with some binary data\xff".hexdump
000000: 02 3A 74 68 69 73 20 69 - 73 20 61 20 73 74 72 69   :.:this is a stri
000010: 6E 67 20 77 69 74 68 20 - 73 6F 6D 65 20 62 69 6E   :ng with some bin
000020: 61 72 79 20 64 61 74 61 - FF                        :ary data.
=> true


Example 2: giving a range with int and hex value calculation

"\x02:this is a string with some binary data\xff".hexdump :range => (16...0x10+0x10)
000010: 6E 67 20 77 69 74 68 20 - 73 6F 6D 65 20 62 69      :ng with some bi
=> true



150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
 
# File 'lib/pentex/core.rb', line 150

def hexdump( opts = {} )
  copts = {
    :bytes => 16,
    :offset => 0,
    :max_bytes => 0,
    :chunksize => 8,
    :range => nil,
    :format => :simple,
    :max_lines => 40
  }
  # lame kind of implementing a command help, anyway better than opening source file ;)

  unless opts.is_a? Hash
    puts "[options]"
    puts copts.to_yaml
    puts
    puts "[example]\n>>'this is a string'.hexdump :max_bytes => 8"
    puts
  return true
  end

  copts.update opts

  dump = ""
  offset = 0
  linecount = 0
  max_bytes = copts[:max_bytes] > 0 ? copts[:max_bytes] : self.length
  if copts[:range].is_a? Range
    offset = copts[:range].min
    max_bytes = copts[:range].max
  end

  counter = offset

  while counter < max_bytes

    pos = sprintf("%06X", counter)

    linelen = (counter < max_bytes - copts[:bytes] ) ? copts[:bytes] : (max_bytes - counter)
    bytes = ""
    linelen.times do |i|
      bytes << "%02X" % self[counter + i].ord
      bytes << " " unless (i+1) % copts[:bytes] == 0
      bytes << "- " if ( i+1) % copts[:chunksize]  == 0 && (i+1) < linelen
    end

    maxlen = ( copts[:bytes] * 2 + copts[:bytes] - 1 + copts[:bytes] / copts[:chunksize] )
    bytes << " " * (maxlen - bytes.length) if maxlen > bytes.length
    ascii = self[counter, linelen].printable
    line = "#{pos}: #{bytes}   :#{ascii}\n"
    puts line
    linecount += 1
    if linecount >= copts[:max_lines]
      puts "<Enter>, [qQ]uit"
      c = gets
      return false if c =~ /^q/i
    linecount = 0
    end
    dump << line
    counter += copts[:bytes]
  end

  return dump unless copts[:format] == :simple

  return true
end