hex replace in autoit

[Kyan]

Hi everyone

I have 2 basic question about hex editing

- I have several texts with a common problem, in stead of having CRLF (carriage return+line feed) only had 0x0A (LF), how do I add 0D behind every 0x0A?

- Its possible to edit only the beginning of a file (speaking in large files that should't be loaded in memory) and save the changes?

[Nessie]

Hi everyone

I have 2 basic question about hex editing

- I have several texts with a common problem, in stead of having CRLF (carriage return+line feed) only had 0x0A (LF), how do I add 0D behind every 0x0A?

- Its possible to edit only the beginning of a file (speaking in large files that should't be loaded in memory) and save the changes?

For the first question maybe? :

$string = "First Line 0x0A Another Line"
$replace_string = StringReplace($string, "0x0A", "0Dx0A")
MsgBox(0,"", "After: " & $string & @CRLF & "Before: " & $replace_string)

For second question give a look _FileWriteToLine function in the help file:

#include <File.au3>
;Example: Write to line 3 of c:\test.txt REPLACING line 3
_FileWriteToLine("c:\test.txt", 3, "my replacement for line 3", 1)
;Example: Write to line 3 of c:\test.txt NOT REPLACING line 3
_FileWriteToLine("c:\test.txt", 3, "my insertion", 0)

Hi!

[Kyan]

For the first question maybe? :

$string = "First Line 0x0A Another Line"
$replace_string = StringReplace($string, "0x0A", "0Dx0A")
MsgBox(0,"", "After: " & $string & @CRLF & "Before: " & $replace_string)

For second question give a look _FileWriteToLine function in the help file:

#include <File.au3>
;Example: Write to line 3 of c:\test.txt REPLACING line 3
_FileWriteToLine("c:\test.txt", 3, "my replacement for line 3", 1)
;Example: Write to line 3 of c:\test.txt NOT REPLACING line 3
_FileWriteToLine("c:\test.txt", 3, "my insertion", 0)

Hi!

thanks for te effort

in your first example it replaces all the data without check if a CR (0x0D) exists before a LF (0x0A), it only needs to and a CR behind a LF which doesn't has a CR already

for the second, in case of bynary file, it would work correctly :s

[Nessie]

thanks for te effort

in your first example it replaces all the data without check if a CR (0x0D) exists before a LF (0x0A), it only needs to and a CR behind a LF which doesn't has a CR already

for the second, in case of bynary file, it would work correctly :s

For the first example maybe is this?:

$string = "First Line 0x0D0x0A Another Line"
$replace_string = StringReplace($string, "0x0D0x0A", "0Dx0A")
MsgBox(0,"", "After: " & $string & @CRLF & "Before: " & $replace_string)

Hi!

Edited February 19, 2013 by Nessie

[Melba23]

DiOgO,

I use this Regex to set every EOL possibility to @CRLF:

#include <Array.au3>

$sText = "Line 1" & @CR & "Line 2" & @LF & "Line 3" & @CRLF & "Line 4" & @LF & "Line 5" & @CR & "Line 6" & @CRLF & "Line 8"

$aLines = StringSplit($sText, @CRLF, 1)
_ArrayDisplay($aLines, "Before")

$sText = StringRegExpReplace($sText, "((?<!\x0d)\x0a|\x0d(?!\x0a))", @CRLF)

$aLines = StringSplit($sText, @CRLF, 1)
_ArrayDisplay($aLines, "After")

It looks for @CR without a following @LF - and @LF without a leading @CR. I hope it helps.

M23

[Kyan]

For the first example maybe is this?:

$string = "First Line 0x0D0x0A Another Line"
$replace_string = StringReplace($string, "0x0D0x0A", "0Dx0A")
MsgBox(0,"", "After: " & $string & @CRLF & "Before: " & $replace_string)

Hi!

not exactly, it is in hex code

DiOgO,

I use this Regex to set every EOL possibility to @CRLF:

#include <Array.au3>

$sText = "Line 1" & @CR & "Line 2" & @LF & "Line 3" & @CRLF & "Line 4" & @LF & "Line 5" & @CR & "Line 6" & @CRLF & "Line 8"

$aLines = StringSplit($sText, @CRLF, 1)
_ArrayDisplay($aLines, "Before")

$sText = StringRegExpReplace($sText, "((?<!\x0d)\x0a|\x0d(?!\x0a))", @CRLF)

$aLines = StringSplit($sText, @CRLF, 1)
_ArrayDisplay($aLines, "After")

It looks for @CR without a following @LF - and @LF without a leading @CR. I hope it helps.

M23

yeah, but what means ?<! and ?! and why is a capture group inside a capture group? (like capturing it 2times xD

btw, you don't know how can a file be edited in a address (0x000024 and lenght 0x2A for i.e.,) and saved without having to copy to another location/file?

[Melba23]

DiOgO,

yeah, but what means ?<! and ?! and why is a capture group inside a capture group? (like capturing it 2times

As I explained, the Regex looks ahead and behind to see if there is the other part of a @CRLF - in which case it does nothing. Let me try and explain:

Follow the numbers in order

(?<!\x0d)     - 2 - Look behind (the ?>! part) and make sure it is NOT preceded by @CR (0x0D)
\x0a        - 1 - Look for @LF (which is 0x0A) then 
|         - 3 - Or
\x0d        - 4 - We look for @CR and then
(?!\x0a)    - 5 - Look ahead (?!) and make sure it is NOT followed by @LF

The parts in () are non-capturing negative lookbehind/lookahead - and are well explained in my favourite Regex tutorial at http://www.regular-expressions.info/tutorial.html.

The whole thing needs to be in () so that it is a capturing group for the SRER to replace.

Any clearer?

M23

Edited February 20, 2013 by Melba23
Fixed url

[Kyan]

DiOgO,

As I explained, the Regex looks ahead and behind to see if there is the other part of a @CRLF - in which case it does nothing. Let me try and explain:

Follow the numbers in order

(?<!\x0d) - 2 - Look behind (the ?>! part) and make sure it is NOT preceded by @CR (0x0D)
\x0a - 1 - Look for @LF (which is 0x0A) then
| - 3 - Or
\x0d - 4 - We look for @CR and then
(?!\x0a) - 5 - Look ahead (?!) and make sure it is NOT followed by @LF

The parts in () are non-capturing negative lookbehind/lookahead - and are well explained in my favourite Regex tutorial at http://www.regular-expressions.info/tutorial.html.

The whole thing needs to be in () so that it is a capturing group for the SRER to replace.

Any clearer?

M23

got it, anyone with doubts check this link http://www.regular-expressions.info/quickstart.html (at the bottom page..."Lookaround")

thanks Melba23, to ask something about sql/timestamps, should I create another thread?

[jchd]

Yes please new topic = new thread