http_chunker

http_chunker is a simple utility for encoding data in the format expeted when

Transfer-Encoding:chunked

is set on an http response.

http_chunker has two options - a desired chunk size, and a max wait time. It will try to read chunk size bytes from input and write them to the output, but if the max wait is reached, it will encode and write out any data it has read.

Why?

I had a need to stream simple commands over http (think ping - it isn't but it's a good example). I didn't want to set up a webserver, write a script to run the command, then create a websocket or javascript poll to update the results.

I wanted use xinetd to transform the process into a service, and write a small script to wrap the http request and response around stdin and stdout. The problem this tool solves is that you either have to use chunked encoding or specify the content length in an http response. I don't know the content length in advance, so need something to encode chunks. http_chunker is that tool.

Examples

$ http_chunker --help
Usage: http_chunker [-w <max-wait>] [-s <chunk-size>]

Read from stdin, chunk and write back out again. After a set delay, write out anything which is queued

Options:
  -w, --max-wait    maximum time (milliseconds) to wait before writing out a
                    partially filled buffer. Set to 0 for no waiting, and -1 to
                    wait forever
  -s, --chunk-size  chunk size
  --help            display usage information

$ echo "hello world!" | http_chunker

D
hello world!

$ echo "hello world!" | ./part94 -s 4

4
hell
4
o wo
4
rld!
1

Compatability

Known to work on linux, expected to work on OS X, BSD or similar, and it would be a pleasant suprise if it worked on Windows.