I'm not sure if there are other implications of this or not, but
the issue is that columns() uses len to store the allocated buffer
size, but linecmp() compares up to len bytes. If those trailing
bytes do not match, the line is considered not matching, even though
the relevant parts of the buffer do match.
To resolve this, also keep track of column capacity. Additionally,
since there is no reason to keep the existing data when resizing,
just use free and emalloc rather than erealloc.
The simplest case I could reduce it to is this:
if [ "$(printf '%s\n' a a xxb xxc | ./sort -u)" = "$(printf '%s\n' a xxb xxc)" ] ; then
echo pass
else
echo fail
fi
In eb9bda8787, a bug was introduced in the
handling of -1 return values from getline. Since the type of the len
field in struct line is unsigned, the break condition was never true.
This caused sort -c to never succeed.
For sort(1) we need memmem(), which I imported from OpenBSD.
Inside sort(1), the changes involved working with the explicit lengths
given by getlines() earlier and rewriting some of the functions.
Now we can handle NUL-characters in the input just fine.
1) Remove the function prototypes. No need for them, as the
functions are ordered.
2) Add fieldseplen, so the length of the field-separator is not
calculated nearly each time skipcolumn() is called.
3) rename next_col to skip_to_next_col so the purpose is clear,
also reorder the conditional accordingly.
4) Put parentheses around certain ternary expressions.
5) BUGFIX: Don't just exit() in check(), but make it return something,
so we can cleanly fshut() everything.
6) OFF-POSIX: Posix for no apparent reason does not allow more than
one file when the -c or -C flags are given.
This can be problematic when you want to check multiple files.
With the change 5), rewriting check() to return a value, I went
off-posix after discussing this with Dimitris to just allow
arbitrary numbers of files. Obviously, this does not break scripts
and is convenient for everybody who wants to quickly check a big
amount of files.
As soon as 1 file is "unsorted", the return value is 1, as expected.
For convenience reasons, check()'s warning now includes the filename.
7) BUGFIX: Set ret to 2 instead of 1 when the fshut(fp, *argv) fails.
8) BUGFIX: Don't forget to fshut stderr at the end. This would improperly
return 1 in the following case:
$ sort -c unsorted_file 2> /dev/full
9) Other style changes, line length, empty line before return.
Make it clear that <blank> characters just are spaces or tabs and
not a special group which needs special treatment for wide characters.
Also, and that was the only problem here, correctly calculate the
offset given by the key definitions for the start- and end-characters
using libutf-utility-functions.
Mark the progress in the README and put parentheses around the missing
flags which are insane to implement for no real gain.
I kind of missed that the sorting was still not properly done.
parse_flags() and addkeydef() are independent of everything else,
so they can be put at the bottom.
Sorting the other functions reveals the true hierarchy much better.
This is much easier to read than having yet another handrolled
list implementation.
Tested and more or less clearly equivalent.
Now that I have uni-vac, I'll have enough time to refactor more.
Get rid of the !!()-constructs and use ret where available (or introduce it).
In some cases, there would be an "abort" on the first fshut-error, but we want
to close all files and report all warnings and then quit, not just the warning
for the first file.
In general, POSIX does not define /dev/std{in, out, err} because it
does not want to depend on the dev-filesystem.
For utilities, it thus introduced the '-'-keyword to denote standard
input (and output in some cases) and the programs have to deal with
it accordingly.
Sadly, the design of many tools doesn't allow strict shell-redirections
and many scripts don't even use this feature when possible.
Thus, we made the decision to implement it consistently across all
tools where it makes sense (namely those which read files).
Along the way, I spotted some behavioural bugs in libutil/crypt.c and
others where it was forgotten to fshut the files after use.
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.
It's not useful when 0 is returned anyway, so be sure that we have a
string with length > 0, this also solves some indexing-gotchas like
"len - 1" and so on.
Also, add checked getline()'s whenever it has been forgotten and
clean up the error-messages.
Sort comes pretty much automatically, as no script relies on the
undefined behaviour of the input _not_ being sorted, we might as well
sort the sorted input already.
The only downside is memory usage, which can be an issue for large
files.
The o-flag was trivial to implement.
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.
Michael Forney
FRIGN
pekka.jylha.ollila@gmail.com
sin
Hiltjo Posthuma
Jakob Kramer