https://github.com/dyng/hexfilter

Read/Write non-printable characters in a printable way.
https://github.com/dyng/hexfilter

Last synced: about 2 months ago
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Read/Write non-printable characters in a printable way.

• Host: GitHub
• URL: https://github.com/dyng/hexfilter
• Owner: dyng
• Created: 2013-11-04T07:21:31.000Z (about 11 years ago)
• Default Branch: master
• Last Pushed: 2013-11-18T12:06:54.000Z (about 11 years ago)
• Last Synced: 2024-04-22T05:10:09.123Z (8 months ago)
• Language: C
• Size: 113 KB
• Stars: 7
• Watchers: 3
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# Hexfilter

Read/Write non-printable characters in a printable way.

## Synopsis

    hexfilter COMMAND [ARG]...

`hexfilter` was originally developed for cracking. It's not rare when you need to input raw hex values in cracking something, usually it is done by `echo` or `printf`. Use `echo` or `printf` to generate the hex string and redirect it to a temp file, then `cat` the file as stdin. However, this way does not work if you need to input interactively. Yes, `hexfilter` is exactly for this.

`hexfilter` takes over subcommand's *stdin*, *stdout* and *stderr*, parses non-printal characters in *stdout*/*stderr* to '\xXX' format and prints it to terminal. Also it accepts the same '\xXX' format for inputing hex characters, converts and passes it to subcommand.

## Compile

`hexfilter` depends on C POSIX library only as you can compile it on UNIX-like system by

    gcc -o hexfilter hexfilter.c

Or if you prefer `clang`, nothing will change

    clang -o hexfilter hexfilter.c

If a Makefile turns out to be necessary, I'll write it, but now I want to keep everything in a simplest way.

## Example

#### Read

    $ echo -ne 'ab\xff\xfe\n' >/tmp/input

    $ cat /tmp/input

    ab??                      # can't properly print '\xff' and '\xfe'

    $ ./hexfilter cat /tmp/input

    ab\xff\xfe                # binary byte '0xff' and '\xfe' are printed as human-readable strings

#### Write

    $ ./hexfilter tee /tmp/output >/dev/null

    ab\xff\xfe                # input hexadecimal value as plain string '\xff' and '\xfe'

    ^C

    $ hexdump /tmp/output

    0000000 61 62 ff fe 0a    # actually in file are exactly those hex characters

    0000005

## TODO

1. End stdin when `CTRL-D` is pressed. (The conventional way to end input but not supported yet)

2. Handle redirection and pipe for subcommand.

## Contribute

I think it is an useful tool but I don't have much time to improve it. **Your contribution is really welcome!**