Documentation:
- Correct the comment documenting the function:
write_full() doesn't write "up to" count bytes (which is write(2)'s
behavior, and exactly what this function is designed to avoid), but
rather exactly count bytes (on success).
- While fixing the documentation, take the time to add a man-page-like
comment as in other APIs. Especially, since we'll have to document
a few other changes from this patch, such as the modified return
values.
- Partial writes are still possible on error. It's the caller's
responsibility to handle that possibility.
API:
- In write(2), it's useful to know how many bytes were transferred,
since it can have short writes. In this API, since it either writes
it all or fails, that value is useless, and callers only want to know
if it succeeded or not. Thus, just return 0 or -1.
Implementation:
- Use `== -1` instead of `< 0` to check for write(2) syscall errors.
This is wisdom from Michael Kerrisk. This convention is useful
because it more explicitly tells maintainers that the only value
which can lead to that path is -1. Otherwise, a maintainer of the
code might be confused to think that other negative values are
possible. Keep it simple.
- The path under `if (res == 0)` was unreachable, since the loop
condition `while (count > 0)` precludes that possibility. Remove the
dead code.
- Use a temporary variable of type `const char *` to avoid a cast.
- Rename `res`, which just holds the result from write(2), to `w`,
which more clearly shows that it's just a very-short-lived variable
(by it's one-letter name), and also relates itself more to write(2).
I find it more readable.
- Move the definition of `w` to the top of the function. Now that the
function is significantly shorter, the lifetime of the variable is
clearer, and I find it more readable this way.
Use:
- Also use `== -1` to check errors.
Cc: Christian Göttsche <cgzones@googlemail.com>
Cc: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
- Every non-const pointer converts automatically to void *.
- Every pointer converts automatically to void *.
- void * converts to any other pointer.
- const void * converts to any other const pointer.
- Integer variables convert to each other.
I changed the declaration of a few variables in order to allow removing
a cast.
However, I didn't attempt to edit casts inside comparisons, since they
are very delicate. I also kept casts in variadic functions, since they
are necessary, and in allocation functions, because I have other plans
for them.
I also changed a few casts to int that are better as ptrdiff_t.
This change has triggered some warnings about const correctness issues,
which have also been fixed in this patch (see for example src/login.c).
Signed-off-by: Alejandro Colomar <alx@kernel.org>
Previous commits, to keep readability of the diffs, left the code that
was previously wrapped by preprocessor coditionals untouched. Apply
some minor cosmetic changes to merge it in the surrounding code.
Signed-off-by: Alejandro Colomar <alx@kernel.org>
On Linux, utmpx and utmp are identical. However, documentation (manual
pages) covers utmp, and just says about utmpx that it's identical to
utmp. It seems that it's preferred to use utmp, at least by reading the
manual pages.
Moreover, we were defaulting to utmp (utmpx had to be explicitly enabled
at configuration time). So, it seems safer to just make it permanent,
which should not affect default builds.
Signed-off-by: Alejandro Colomar <alx@kernel.org>
strftime(3) has been in standard C since C89. It is also in
POSIX.1-2001, and in SVr4 (see strftime(3) and strftime(3p)).
We can assume that this function is always available.
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
boolean.
* libmisc/basename.c: Avoid implicit conversion of pointer to
boolean.
* libmisc/basename.c, lib/prototypes.h (Basename): Return a
constant string.
* libmisc/basename.c, libmisc/obscure.c, lib/prototypes.h,
libmisc/xmalloc.c, libmisc/getdate.h, libmisc/system.c,
libmisc/getgr_nam_gid.c, libmisc/failure.c, libmisc/valid.c: Add
splint annotations.
* libmisc/chowndir.c: Avoid memory leak.
* libmisc/chowndir.c: Do not check *printf/*puts return value.
* libmisc/chowntty.c: Avoid implicit conversion between integer
types.
* libmisc/obscure.c: Return a bool when possible instead of int.
* libmisc/shell.c: Do not check *printf/*puts return value.
* libmisc/shell.c: Do not check execle return value.
* libmisc/setupenv.c: Avoid implicit conversion between integer
types.
* libmisc/xmalloc.c: size should not be zero to avoid returning
NULL pointers.
* libmisc/hushed.c: Do not check *printf/*puts return value.
* libmisc/system.c: Avoid implicit conversion of integer to
boolean. safe_system last argument is a boolean.
* libmisc/system.c: Check return value of dup2.
* libmisc/system.c: Do not check *printf/*puts return value.
* libmisc/system.c: Do not check execve return value.
* libmisc/salt.c: Do not check *printf/*puts return value.
* libmisc/loginprompt.c: Do not check gethostname return value.
* libmisc/find_new_gid.c, libmisc/find_new_uid.c: Do not check
gr_rewind/pw_rewind return value.
* libmisc/ttytype.c: Limit the number of parsed characters in the
sscanf format.
* libmisc/ttytype.c: Test if a type was really read.
* libmisc/sub.c: Do not check *printf/*puts return value.
* libmisc/sub.c: Avoid implicit conversion of integer to boolean.
* src/userdel.c: Fix typo in comment.
* src/userdel.c: Avoid implicit conversion of boolean to integer.
* src/userdel.c: safe_system last argument is a boolean.
* src/newusers.c: Avoid implicit conversion of boolean to integer.
* src/newusers.c: Avoid implicit conversion of integer to boolean.
* src/usermod.c: Add brackets.
* src/usermod.c: Avoid implicit conversion of characters or
integers to booleans.
* src/vipw.c: Avoid implicit conversion of integer to boolean.
* src/su.c: Avoid implicit conversion of integer to boolean.
* src/su.c: Add brackets.
* src/useradd.c: Avoid implicit conversion of characters or
integers to booleans.
libmisc/sulog.c, libmisc/hushed.c, libmisc/failure.c,
libmisc/loginprompt.c, libmisc/ttytype.c,
libmisc/pam_pass_non_interractive.c, src/userdel.c, src/login.c,
lib/commonio.c, lib/commonio.h: Fix some const issues.
* libmisc/motd.c: Avoid multi-statements lines.
* libmisc/motd.c: Support long MOTD_FILE.
* libmisc/list.c, lib/prototypes.h: Revert previous change.
dup_list and is_on_list are used with members as defined for the
group structure, and thus even if the list is not modified, the
list elements cannot be constant strings.
* libmisc/system.c: Avoid C++ comments.
* src/vipw.c: WITH_TCB cannot be tested inside a gettextized
string. Split the Usage string.
* lib/commonio.h: Re-indent.
username as first parameter of failtmp to avoid issues with
non-null terminated ut_user, unavailability of ut_user, incomplete
username (that should not happen currently).
reading or writing at an unspecified location. Log to syslog in
case of failure when reading a faillog entry or writing in
faillog or btmp.
* libmisc/failure.c: Check if the file exist before opening it.
* libmisc/failure.c: Log failures of open() and close() when
necessary.
* libmisc/failure.c: read() returns a ssize_t.
* libmisc/failure.c: Add brackets and parenthesis.
* libmisc/failure.c: Ignore return value of time() when use with a
non NULL argument.
Files with no license use the default 3-clauses BSD license. The copyright
were mostly not recorded; they were updated according to the Changelog.
"Julianne Frances Haugh and contributors" changed to "copyright holders
and contributors".
