How does -b option in sed program perform usefully

BudiKusasi · 04-04-2017, 08:00 AM

How is the usage of -b option in sed, stream editor utility. I've been trying to find & replace a unicode text inside binary data. Which are sed's options and its command line would be to perform correct result.
For example the text 'collon' is among the binary, i.e invisible characters, and would be replaced with 'period'. So hex illustration looks like:
0 1 2 3 4 5 6 7 8 9 a b c d e f

09 29 0d 0a 63 00 6f 00 6c 00 6c 00 6f 00 6e 00 ....collon
...
... so on
Expected to become:
09 29 0d 0a 70 00 65 00 72 00 69 00 6f 00 64 00 ....period

What should I do, anyone please help me... many thanks in advance

rtmistler · 04-04-2017, 10:14 AM

I've not used bbe which is a binary file editor replacement for sed. Usually when I manipulate binary files, I write a program to do so.

Either case, sed does do binary format, and I'm unsure, but there are also awk and tr commands which likely will do the same.

The issue is how to represent the binary characters, using printable ASCII, because you have to type something using escape clauses to identify the binary, or hex sequences you intend to find, edit, and replace. I believe the notation is \x prior to the number.

Have you managed to write any starting commands to find the sequence or sequences you are looking to identify for changes?

chrism01 · 04-05-2017, 03:13 AM

Looking at the man page, I don't think -b does what you think

Code:

-b
--binary

    This option is available on every platform, but is only effective where
 the operating system makes a distinction between text files and binary 
files. When such a distinction is made—as is the case for MS-DOS, Windows, 
Cygwin—text files are composed of lines separated by a carriage return and 
a line feed character, and sed does not see the ending CR. When this option 
is specified, sed will open input files in binary mode, thus not requesting 
this special processing and considering lines to end at a line feed.

However, this page gives a detailed example of how to do what you want
https://everydaywithlinux.blogspot.c...-with-sed.html

BudiKusasi · 04-05-2017, 03:33 AM

Thank you much , I do appreciate. I'm looking the page up..