HexView.bas by Walt Grams. Used by permission.
mailto:wjgrams@yahoo.com

Date: Sun, 06 Oct 2002
Subject: [libertybasic] HexView.bas

Here is a little program I wrote to allow one to view the contents of any file on a byte by byte basis. Each byte in the file is displayed as both a two digit hexadecimal number and the corresponding ASCII character. Try it on several different types of files to see what the various formats look like internally.

Just for fun try a Microsoft Word file. It is amazing what they keep in your files.

Anyone looking for a challenge can turn this into a full hexadecimal file editor. :-)

Walt

'Displays the contents of any file as the hexadecimal values
'of the individual data bytes in the file and also as the
'corresponding ASCII characters

dim s$(16)
dim h$(16)
NOMAINWIN
WindowWidth = 500
WindowHeight = 380
UpperLeftX = 200
UpperLeftY = 150
statictext #hexView.fname, "File Name: ", 5, 10, 350, 14
button #hexView.cf, "Choose File", [CFClicked], UL, 370, 7, 100, 25
button #hexView.nxt, "Next", [NextClicked], Ul, 370, 45, 0, 0
button #hexView.prv, "Previous", [PrevClicked], UL, 370, 75, 0, 0
statictext #hexView.alabel, "Hexadecimal address:", 370, 125, 150, 15
textbox #hexView.addr, 370, 145, 50, 25
button #hexView.go, "Go", [GoClicked], UL, 430, 145, 0, 0
textbox #hexView.field, 50, 45, 300, 270
statictext #hexView.hexlabel, "Hexadecimal View", 53, 32, 130, 14
statictext #hexView.textlabel, "Text View", 270, 32, 50, 14
statictext #hexView.addrlabel1, "000000:", 5, 50, 45, 14
statictext #hexView.addrlabel2, "000020:", 5, 114, 45, 14
statictext #hexView.addrlabel3, "000040:", 5, 178, 45, 14
statictext #hexView.addrlabel4, "000060:", 5, 242, 45, 14
open "Hex View" for window as #hexView
print #hexView, "trapclose [quit]"
print #hexView.field, "!font Courier_New 10";
wait

[quit]
close #hexView
end

[GoClicked]
print #hexView.addr, "!contents? hexAddr$";
startLoc = hexdec(hexAddr$)
if startLoc < 0 then startLoc = 0
if currentFile$="" then wait
goto [ShowData]

[PrevClicked]
startLoc = startLoc - 128
if startLoc < 0 then startLoc = 0
if currentFile$="" then wait
goto [ShowData]

[NextClicked]
startLoc = startLoc + 128
if currentFile$="" then wait
goto [ShowData]


[CFClicked]
filedialog "Open file to view", "*.*", fileName$

if fileName$="" then wait
startLoc = 0
print #hexView.nxt, "!locate 370, 45, 100, 25"
print #hexView.go, "!locate 430, 145, 40, 25"
currentFile$ = fileName$

[ShowData]
open currentFile$ for input as #f
print #hexView.fname, "File Name: " + currentFile$
if startLoc > 5000 then print #hexView.field, "One moment please ..."
if startLoc > 0 then
  for x = 1 to startLoc
    if eof(#f)=0 then x$ = input$(#f,1)
  next x
  print #hexView.prv, "!locate 370, 75, 100, 25"
else
  print #hexView.prv, "!locate 370, 75, 0, 0"
end if
hexaddr1$ = pad$(dechex$(startLoc))
hexaddr2$ = pad$(dechex$(startLoc + 32))
hexaddr3$ = pad$(dechex$(startLoc + 64))
hexaddr4$ = pad$(dechex$(startLoc + 96))
print #hexView.addrlabel1, hexaddr1$; ":"
print #hexView.addrlabel2, hexaddr2$; ":"
print #hexView.addrlabel3, hexaddr3$; ":"
print #hexView.addrlabel4, hexaddr4$; ":"
disp$ = ""
for index1 = 0 to 15
  s$(index1) = ""
  h$(index1) = ""
  for index2 = 0 to 7
    if eof(#f)=0 then
      val = asc(input$(#f,1))
      if val = 10 or val = 13 or val = 0 or val = 9 then
        s$(index1) = s$(index1) + " "
      else
        s$(index1) = s$(index1) + chr$(val)
      end if
      hexval$ = dechex$(val)
      if len(hexval$)<2 then hexval$ = "0" + hexval$
      h$(index1) = h$(index1) + hexval$ + " "
    else
      s$(index1) = s$(index1) + " "
      h$(index1) = h$(index1) + ".. "
    end if
    if index2=3 then h$(index1) = h$(index1) + " "
  next index2
  disp$ = disp$ + h$(index1) + "  " + s$(index1) + chr$(13) + chr$(10)
next index1
print #hexView.field, disp$
close #f
print #hexView, "refresh"
wait

function pad$(h$)
while len(h$) < 6
  h$ = "0" + h$
wend
pad$ = h$
end function

'end of program (watch for line wraps)