simon-git: reservoir (master): Simon Tatham

[Commits to Tartarus hosted VCS]

TL;DR:
  0972663 Support -a to append to an existing output file.

Repository:     https://git.tartarus.org/simon/reservoir.git
On the web:     https://git.tartarus.org/?p=simon/reservoir.git
Branch updated: master
Committer:      Simon Tatham <anakin at pobox.com>
Date:           2020-03-19 12:14:44

commit 0972663e71196454e81a1b7833501e0fb92bc074
web diff https://git.tartarus.org/?p=simon/reservoir.git;a=commitdiff;h=0972663e71196454e81a1b7833501e0fb92bc074;hp=0aff497a276baa7a17260b485d3e2aa25d785b4e
Author: Simon Tatham <anakin at pobox.com>
Date:   Thu Mar 19 12:14:40 2020 +0000

    Support -a to append to an existing output file.
    
    Works just like -O / -o, but opens the output file with ">>" instead
    of ">" (in Perl terms).
    
    In this mode, it doesn't matter very much whether we check for an
    empty data buffer: it makes no difference to the output file if we
    append an empty buffer to it or don't append anything to it. But I
    think it's slightly nicer in that situation to not even bother opening
    it for writing; that will preserve its existing timestamp, so that if
    it's a source file in a Makefile, it won't cause unnecessary rebuilds.
    
    (I suppose an alternative point of view would be that it also doesn't
    diagnose the file being read-only, which you might prefer to find out
    this time rather than waiting until later when there _is_ data to
    write. Anyone who wants this 'unconditionally attempt the append'
    behaviour is welcome to send a patch adding -A alongside -a!

 reservoir     |  6 ++++--
 reservoir.but | 13 +++++++++++++
 2 files changed, 17 insertions(+), 2 deletions(-)