~maelkum/stream-buffer

Buffer data from standard input
0cc88722 — Marek Marecki 9 months ago
Relase 0.2.0
9813639f — Marek Marecki 9 months ago
Fix buffer hanging if pipe is not readable on exit
411dd671 — Marek Marecki 9 months ago
Fix crash on incorrect size specification

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#stream-buffer

Buffer data received on standard input.

The stream-buffer receives data on standard input and buffers it before sending to its standard output stream.


#Installation

Assuming you have GCC installed, these commands should install stream-buffer on your system:

$ make -j 4
$ make PREFIX=~/.local install

To uninstall the program:

$ make PREFIX=~/.local uninstall

Two executables are produced and installed:

  • stream-buffer: the main executable
  • stream-buffer-ctl: the support program providing control over running buffers

#Examples

Some quick-start commands.

#Starting the buffer

Use the buffer as you would use, e.g., tee(1) - pipe the output of some process to it and let stream buffer handle buffering:

$ some-process --produce=logs | stream-buffer 64KiB > some-process.log

#Resizing buffers

Resize the buffer while it is streaming data:

$ stream-buffer-ctl 123456 resize 8KiB

Be aware that the buffer is flushed before resizing.

#Flushing buffers

Flushing buffer is accomplished by sending it the SIGHUP signal:

$ kill -s SIGHUP 123456
$ stream-buffer-ctl 123456 flush

Do it either using kill(1) or the control program.


#Why not stdbuf(1)?

Because stdbuf(1) works by adjusting standard streams settings and then execvp(2)-ing the program. This means that:

  • if the "buffered" program adjusts these settings by itself stdbuf(1) does nothing to affect that

stream-buffer works by placing itself as a middleman - it receives data on standard input, buffers it, and sends it to its standard output. Thus, even if the program adjusts its stream settings stream-buffer it will not matter because the program cannot affect what stream-buffer does.


#License

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.