Commit Graph

20 Commits

Author SHA1 Message Date
FRIGN 11e2d472bf Add *fshut() functions to properly flush file streams
This has been a known issue for a long time. Example:

printf "word" > /dev/full

wouldn't report there's not enough space on the device.
This is due to the fact that every libc has internal buffers
for stdout which store fragments of written data until they reach
a certain size or on some callback to flush them all at once to the
kernel.
You can force the libc to flush them with fflush(). In case flushing
fails, you can check the return value of fflush() and report an error.

However, previously, sbase didn't have such checks and without fflush(),
the libc silently flushes the buffers on exit without checking the errors.
No offense, but there's no way for the libc to report errors in the exit-
condition.

GNU coreutils solve this by having onexit-callbacks to handle the flushing
and report issues, but they have obvious deficiencies.
After long discussions on IRC, we came to the conclusion that checking the
return value of every io-function would be a bit too much, and having a
general-purpose fclose-wrapper would be the best way to go.

It turned out that fclose() alone is not enough to detect errors. The right
way to do it is to fflush() + check ferror on the fp and then to a fclose().
This is what fshut does and that's how it's done before each return.
The return value is obviously affected, reporting an error in case a flush
or close failed, but also when reading failed for some reason, the error-
state is caught.

the !!( ... + ...) construction is used to call all functions inside the
brackets and not "terminating" on the first.
We want errors to be reported, but there's no reason to stop flushing buffers
when one other file buffer has issues.
Obviously, functionales come before the flush and ret-logic comes after to
prevent early exits as well without reporting warnings if there are any.

One more advantage of fshut() is that it is even able to report errors
on obscure NFS-setups which the other coreutils are unable to detect,
because they only check the return-value of fflush() and fclose(),
not ferror() as well.
2015-04-05 09:13:56 +01:00
Hiltjo Posthuma a9bedca038 fix some signed/unsigned warnings and style fixes 2015-03-27 22:48:05 +01:00
FRIGN 5af4cdcd60 Audit unexpand(1)
I checked the algorithm already a while ago. What was left was a
couple of style-fixes.
2015-03-17 23:45:03 +01:00
FRIGN 3b825735d8 Implement reallocarray()
Stateless and I stumbled upon this issue while discussing the
semantics of read, accepting a size_t but only being able to return
ssize_t, effectively lacking the ability to report successful
reads > SSIZE_MAX.
The discussion went along and we came to the topic of input-based
memory allocations. Basically, it was possible for the argument
to a memory-allocation-function to overflow, leading to a segfault
later.
The OpenBSD-guys came up with the ingenious reallocarray-function,
and I implemented it as ereallocarray, which automatically returns
on error.
Read more about it here[0].

A simple testcase is this (courtesy to stateless):
$ sbase-strings -n (2^(32|64) / 4)

This will segfault before this patch and properly return an OOM-
situation afterwards (thanks to the overflow-check in reallocarray).

[0]: http://www.openbsd.org/cgi-bin/man.cgi/OpenBSD-current/man3/calloc.3
2015-03-10 21:23:36 +01:00
Hiltjo Posthuma 5a6715c0cf unexpand: spaces to tabs 2015-02-20 13:29:38 +01:00
sin 9effb224c8 expand, unexpand: Minor style fix as per the suckless guide 2015-02-17 12:14:44 +00:00
FRIGN 31572c8b0e Clean up #includes 2015-02-14 21:12:23 +01:00
FRIGN 7c578bf5b0 Scrap writerune(), introducing fputrune()
Interface and function as proposed by cls.
Code is also shorter, everything else analogous to fgetrune().
2015-02-11 20:58:00 +01:00
FRIGN a5ae899a48 Scrap readrune(), introducing fgetrune()
Interface as proposed by cls, but internally rewritten after a few
considerations.
The code is much shorter and to the point, aligning itself with other
standard functions. It should also be much faster, which is not bad.
2015-02-11 20:16:49 +01:00
FRIGN 1b4ba2b303 Remove wchar.h from unexpand(1)
not needed any more.
2015-02-09 00:20:02 +01:00
sin 6397952ab3 Nuke bogus newline 2015-02-08 20:28:18 +00:00
FRIGN 1513c2b766 Refactor unexpand(1) code and manpage, adding tablist support
as already seen for expand(1), only twice as complicated.
2015-02-08 21:24:22 +01:00
FRIGN fd562481f3 Convert estrto{l, ul} to estrtonum
Enough with this insanity!
2015-01-30 16:52:44 +01:00
Hiltjo Posthuma 3d8d796a95 unexpand: fix eprintf 2014-12-22 10:34:29 +00:00
sin cd35347203 Convert unexpand(1) to libutf 2014-11-21 17:52:22 +00:00
sin af8e38f5fa Fix some error messages
There's many more to go.
2014-11-17 16:22:01 +00:00
FRIGN ec8246bbc6 Un-boolify sbase
It actually makes the binaries smaller, the code easier to read
(gems like "val == true", "val == false" are gone) and actually
predictable in the sense of that we actually know what we're
working with (one bitwise operator was quite adventurous and
should now be fixed).

This is also more consistent with the other suckless projects
around which don't use boolean types.
2014-11-14 10:54:20 +00:00
FRIGN eee98ed3a4 Fix coding style
It was about damn time. Consistency is very important in such a
big codebase.
2014-11-13 18:08:43 +00:00
sin 0c5b7b9155 Stop using EXIT_{SUCCESS,FAILURE} 2014-10-02 23:46:59 +01:00
Tuukka Kataja 8b87d0098a Add unexpand(1) 2014-06-09 17:00:13 +01:00