Commit Graph

17 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
FRIGN 31572c8b0e Clean up #includes 2015-02-14 21:12:23 +01:00
FRIGN 28b4b25076 Refactor uname(1) code and manpage
remove stdlib.h-include which was there for no reason and clear
up the manpage.
2015-02-07 22:15:56 +01:00
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 7d2683ddf2 Sort includes and more cleanup and fixes in util/ 2014-11-14 10:54:10 +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
Hiltjo Posthuma 953ebf3573 code style
Signed-off-by: Hiltjo Posthuma <hiltjo@codemadness.org>
2014-06-01 18:02:30 +01:00
sin b5a511dacf Exit with EXIT_SUCCESS/EXIT_FAILURE instead of 0 and 1
Fixed for consistency purposes.
2013-10-07 16:44:22 +01:00
stateless 7216a53a7e Remove unnecessary exit(1) in usage()
Signed-off-by: Christoph Lohmann <20h@r-36.net>
2013-06-19 19:58:19 +02:00
Christoph Lohmann 4d38f60685 Eliminating the getopt disgrace. 2013-06-14 20:20:47 +02:00
Connor Lane Smith 5156758e21 kill -l 2011-06-10 02:56:13 +01:00
Connor Lane Smith 17a81ace44 extra uname spaces confuse scripts 2011-06-09 00:40:23 +01:00
Connor Lane Smith d90ced2047 consistent error check 2011-06-04 12:20:41 +01:00
Connor Lane Smith e565522068 ln -f 2011-06-04 02:56:18 +01:00
Connor Lane Smith 894b42a885 add tty 2011-06-02 21:15:35 +01:00
Connor Lane Smith 92baf1a5c9 add uname, thanks hiltjo 2011-06-02 20:32:05 +01:00