Add a page documenting the pthread_attr_setsigmask_np(3) and
pthread_attr_getsigmask_np() functions added in glibc 2.32.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
queue.3 has been moved to queue.7.
Fix SEE ALSO accordingly.
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
queue has been for so many years in Section 3,
and still is in Section 3 in most manuals.
For legacy reasons,
especially because hyperlinks to the online manual pages
would break otherwise,
a link queue.3 -> queue(7) is necessary.
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
After forking slist.3, list.3, tailq.3, stailq.3 & circleq.3
in the previous commits,
this page no longer belongs in Section 3 of the manual pages.
According to its contents, the most suitable section is Section 7.
Because of legacy reasons, a link queue.3 -> queue(7)
would be appropriate.
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This helps differentiate 'TYPE' in some arguments from
'struct TYPE *var' in others, and is technically more correct.
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
- ffix: Use man markup
- Remove specific notes about code size increase
and execution time increase,
as they were (at least) inaccurate.
Instead, a generic note has been added.
- Structure the text into subsections.
- Remove sections that were empty after the forks.
- Clearly relate macro names (SLIST, TAILQ, ...)
to a human readable name of which data structure
they implement.
Reported-by: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Add remaining details to complete the page.
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
A few fixes to note:
- Sorted alphabetically some macros
- ffix: remove alignment spaces in example (as in list.3)
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
list.3: NAME: Add description
list.3: DESCRIPTION: Add short description
list.3: SEE ALSO: Add insque(3) and queue(3)
list.3: BUGS: Note LIST_FOREACH() limitations
list.3: RETURN VALUE: Add details about the return value of those macros that "return" a value
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
list.3: NAME: ffix: Use man markup
list.3: SYNOPSIS: ffix: Use man markup
list.3: DESCRIPTION: ffix: Use man markup
list.3: DESCRIPTION: ffix: Use man markup
list.3: CONFORMING TO: ffix: Use man markup
list.3: EXAMPLES: ffix: Use man markup
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
list.3: SYNOPSIS: Copy include from queue.3
list.3: DESCRIPTION: Copy description about naming of macros from queue.3
list.3: DESCRIPTION: Remove unrelated code to adapt to this page
list.3: DESCRIPTION: Remove lines pointing to the EXAMPLES
list.3: CONFORMING TO: Copy from queue.3
list.3: CONFORMING TO: Adapt to this page
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The wording was incorrect:
It stated that 'eflags' may be the OR of one or two of those two flags,
but then a third flag was documented
(which according to the previous wording could not be used?!).
Moreover, the wording also disallowed using 0 (i.e., no flags at all),
which POSIX specifically allows;
I tested the function with no flags and it worked fine for me,
so I guess it was a problem with the documentation,
and not with the implementation itself.
POSIX ref: https://pubs.opengroup.org/onlinepubs/9699919799/
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
I added the EXAMPLES section.
The examples in this page are incomplete
(you can't copy&paste&compile&run).
I fixed the one about TAILQ first,
and the rest should follow.
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
POSIX requires that the <regex.h> header shall define
the structures and symbolic constants used by the
regcomp(), regexec(), regerror(), and regfree() functions.
Therefore, there should be no need to include <sys/types.h>
at all.
The POSIX docs don't use that include:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/regcomp.html
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Revert "uint_least8_t.3, uint_least16_t.3, uint_least32_t.3, uint_least64_t.3, uint_leastN_t.3: New links to system_data_types(7)"
This reverts commit a5d13a32b7.
Revert "system_data_types.7: Add uint_leastN_t family of types"
This reverts commit 3450a5621e.
Revert "int_least8_t.3, int_least16_t.3, int_least32_t.3, int_least64_t.3, int_leastN_t.3: New links to system_data_types(7)"
This reverts commit 876838354d.
Revert "system_data_types.7: Add int_leastN_t family of types"
This reverts commit f9b54d3a2e.
Revert "uint_fast8_t.3, uint_fast16_t.3, uint_fast32_t.3, uint_fast64_t.3, uint_fastN_t.3: New links to system_data_types(7)"
This reverts commit 496b1aad79.
Revert "system_data_types.7: Add uint_fastN_t family of types"
This reverts commit 3c9ae6e5a2.
Revert "int_fast8_t.3, int_fast16_t.3, int_fast32_t.3, int_fast64_t.3, int_fastN_t.3: New links to system_data_types(7)"
This reverts commit 9df81a23e5.
Revert "system_data_types.7: Add int_fastN_t family of types"
This reverts commit 8f12d3f683.
Reported-by: Michael Kerrisk <mtk.manpages@gmail.com>
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Through some accident, 'sys_siglist' has been documented in
two different pages. Consolidate the information to one page
(strsignal(3)) and add 'sys_siglist" to the NAME line of that
page.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Around the text:
"Feature Test Macro Requirements for glibc..."
replace ".in -4n/.in" with ".RS -4/.RE".
The latter form is more idiomatic use of man macros.
The nroff output is unchanged.
Reported-by: G. Branden Robinson <g.branden.robinson@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use \(aq to get an unslanted single quote inside monospace code
blocks. Using a simple ' results in a slanted quote inside PDFs.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
[mtk: the coding style used in the example could lead people to
inject memory leaks in their code if they cut/paste/modify the
code to replace "exit" paths with "return" paths from a library
function.]
[Marko, from the mail thread discussing this patch:]
You are right about terminating the process. However, people copy
that example and put the code in a function changing "exit" to
"return". There are a bunch of examples like that here
https://beej.us/guide/bgnet/html/#poll, for instance. That error
bothered me when reading the network programming guide
https://beej.us/guide/bgnet/html/. Than I looked for information
elsewhere:
https://stackoverflow.com/questions/6712740/valgrind-reporting-that-getaddrinfo-is-leaking-memoryhttps://stackoverflow.com/questions/15690303/server-client-sockets-freeaddrinfo3-placement
And finally, I checked manual pages and saw where these errors
come from.
When you change that to a function and return without doing
freeaddrinfo, that is a memory leak. I believe an example should
show good programming practices. Relying on exiting and clearing
the memory in that case is not such a case. In my opinion, these
examples lead people to make mistakes in their programs.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Let's move to the 21st century. Instead of casting system data
types to long/long long/etc. in printf() calls, instead cast to
intmax_t or uintmax_t, the largest available signed/unsigned
integer types.
[mtk: rewrote commit message]
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use printf()'s '#' flag character to prepend the string "0x".
However, when the number is printed in uppercase, and the prefix
is in lowercase, the string "0x" needs to be manually written.
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
For consistency.
The types are written both with and without the redundant 'int' keyword
all over the man-pages. However, the most used form, by far, is the one
without 'int'.
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Member 'tv_nsec' of 'struct timespec' is of type 'long' (see time.h.0p),
and therefore, the cast is completely redundant.
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
For consistency.
Most man pages use 'long' instead of 'long int'.
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
It is the DT_RUNPATH/DT_RPATH of the calling object (not the
executable) that is relevant for the library search. Verified
by experiment.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
fread(3), unlike read(2) which returns a ssize_t, returns a
size_t. It doesn't distinguish between error and enf-of-file.
Instead, either ferror(3) or feof(3) need to be checked if fread()
returned 0.
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
`p1` (and `p2` too) is `const void *` and it comes from a
`const char **` (for legacy reasons, argv is not `const` but should be
treated as if it were). That means, the ultimate `char` is `const`:
"a pointer to a pointer to a const char".
Let's see what is going on before the fix first, and then the fix.
Before the fix:
`(char *const *)` (I removed the space on purpose) casts `p1` to be
"a pointer to a const pointer to a non-const char". That's clearly
not what it originally was.
Then we dereference, ending with a `char *const`, which is
"a const pointer to a non-const char". But given that the pointer value
is passed to a function, `const` doesn't make sense there, because the
function will already take a copy of it, so it is impossible to modify
the pointer itself.
The fix:
`(const char **)` The only thing that is const is the ultimate `char`,
which is the only thing that matters, because it is the only thing
strcmp(3) has access to (everything else, i.e. the pointers, are
copies).
Then, after the dereference we end up with `const char *`, the type of
argv (more or less, as previously noted), which is also the type of the
arguments to strcmp(3).
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Casting `const void *` to `struct mi *` should result in a warning if
done implicitly. The explicit cast was probably silencing that warning.
`const` can and should be kept.
Now, casting `const void *` to `const struct mi *` is done implicitly.
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The type `sigset_t *` is implicitly casted to `void *`.
Explicitly casting can silence warnings when mistakes are made, so it's
better to remove those casts when possible.
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Casting `void *` to `double (*cosine)(double)` is already done
implicitly.
I had doubts about this one, but `gcc -Wall -Wextra` didn't complain
about it.
Explicitly casting can silence warnings when mistakes are made, so it's
better to remove those casts when possible.
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The type of `val` is `int **`, and it will work with tsearch()
anyway because of implicit cast from `void *`, so declaring it as an
`int **` simplifies the code.
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Casting `int *` to `const void *` is already done implicitly.
Not only that, but the explicit cast to `void *` was slightly
misleading.
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Rather than:
sometype x;
for (x = ....; ...)
use
for (sometype x = ...; ...)
This brings the declaration and use closer together (thus aiding
readability) and also clearly indicates the scope of the loop
counter variable.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Rather than writing things such as:
struct sometype *x;
...
x = malloc(sizeof(*x));
let's use C99 style so that the type info is in the same line as
the allocation:
struct sometype *x = malloc(sizeof(*x));
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use ``sizeof`` consistently through all the examples in the following
way:
- Use the name of the variable instead of its type as argument for
``sizeof``.
Rationale:
https://www.kernel.org/doc/html/v5.8/process/coding-style.html#allocating-memory
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use ``sizeof`` consistently through all the examples in the following
way:
- Use the name of the variable instead of its type as argument for
``sizeof``.
Rationale:
https://www.kernel.org/doc/html/v5.8/process/coding-style.html#allocating-memory
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use ``sizeof`` consistently through all the examples in the following
way:
- Use the name of the variable instead of its type as argument for
``sizeof``.
Rationale:
https://www.kernel.org/doc/html/v5.8/process/coding-style.html#allocating-memory
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use ``sizeof`` consistently through all the examples in the following
way:
- Use the name of the variable instead of its type as argument for
``sizeof``.
Rationale:
https://www.kernel.org/doc/html/v5.8/process/coding-style.html#allocating-memory
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use ``sizeof`` consistently through all the examples in the following
way:
- Use the name of the variable instead of its type as argument for
``sizeof``.
Rationale:
https://www.kernel.org/doc/html/v5.8/process/coding-style.html#allocating-memory
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use ``sizeof`` consistently through all the examples in the following
way:
- Use the name of the variable instead of its type as argument for
``sizeof``.
Rationale:
https://www.kernel.org/doc/html/v5.8/process/coding-style.html#allocating-memory
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use ``sizeof`` consistently through all the examples in the following
way:
- Use the name of the variable instead of its type as argument for
``sizeof``.
Rationale:
https://www.kernel.org/doc/html/v5.8/process/coding-style.html#allocating-memory
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use ``sizeof`` consistently through all the examples in the following
way:
- Use the name of the variable instead of its type as argument for
``sizeof``.
Rationale:
https://www.kernel.org/doc/html/v5.8/process/coding-style.html#allocating-memory
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use ``sizeof`` consistently through all the examples in the following
way:
- Use the name of the variable instead of its type as argument for
``sizeof``.
Rationale:
https://www.kernel.org/doc/html/v5.8/process/coding-style.html#allocating-memory
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use ``sizeof`` consistently through all the examples in the following
way:
- Use the name of the variable instead of its type as argument for
``sizeof``.
Rationale:
https://www.kernel.org/doc/html/v5.8/process/coding-style.html#allocating-memory
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use ``sizeof`` consistently through all the examples in the following
way:
- Use the name of the variable instead of its type as argument for
``sizeof``.
Rationale:
https://www.kernel.org/doc/html/v5.8/process/coding-style.html#allocating-memory
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use ``sizeof`` consistently through all the examples in the following
way:
- Use the name of the variable instead of its type as argument for
``sizeof``.
Rationale:
https://www.kernel.org/doc/html/v5.8/process/coding-style.html#allocating-memory
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use ``sizeof`` consistently through all the examples in the following
way:
- Use the name of the variable instead of its type as argument for
``sizeof``.
Rationale:
https://www.kernel.org/doc/html/v5.8/process/coding-style.html#allocating-memory
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use ``sizeof`` consistently through all the examples in the following
way:
- Use the name of the variable instead of its type as argument for
``sizeof``.
Rationale:
https://www.kernel.org/doc/html/v5.8/process/coding-style.html#allocating-memory
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use ``sizeof`` consistently through all the examples in the following
way:
- Use the name of the variable instead of its type as argument for
``sizeof``.
Rationale:
https://www.kernel.org/doc/html/v5.8/process/coding-style.html#allocating-memory
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use ``sizeof`` consistently through all the examples in the following
way:
- Use the name of the variable instead of its type as argument for
``sizeof``.
Rationale:
https://www.kernel.org/doc/html/v5.8/process/coding-style.html#allocating-memory
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use ``sizeof`` consistently through all the examples in the following
way:
- Use the name of the variable instead of its type as argument for
``sizeof``.
Rationale:
https://www.kernel.org/doc/html/v5.8/process/coding-style.html#allocating-memory
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use ``sizeof`` consistently through all the examples in the
following way:
- When the result of ``sizeof`` is multiplied (or otherwise
modified), write ``sizeof`` in the first place.
Rationale:
``(sizeof(x) * INT_MAX * 2)`` doesn't overflow.
``(INT_MAX * 2 * sizeof(x))`` overflows, giving incorrect
results.
As a side effect, the parentheses of ``sizeof`` are not next to
the parentheses of the whole expression, and it is visually
easier to read.
Detailed rationale:
In C, successive multiplications are evaluated left to right (*),
and therefore here is what happens (assuming x86_64):
``(sizeof(x) * INT_MAX * 2)``:
1) sizeof(x) * INT_MAX (the type is the largest of both, which
is size_t (unsigned long; uint64_t)).
2) ANS * 2 (the type is again the largest: size_t)
``(INT_MAX * 2 * sizeof(x))``:
1) INT_MAX * 2 (the type is the largest of both, which is
int as both are int (int; int32_t), so the
result is already truncated as it doesn't fit
an int; at this point, the intermediate result
will be 2^32 - 2 (``INT_MAX - 1``) (if I did
the math right)).
2) ANS * 2 (the type is again the largest of both: size_t;
however, ANS was already incorrect, so the
result will be an incorrect size_t value)
(*): https://en.cppreference.com/w/c/language/operator_precedence
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Use ``sizeof`` consistently through all the examples in the
following way:
- Never use a space after ``sizeof``, and always use parentheses
around the argument.
Rationale:
https://www.kernel.org/doc/html/v5.8/process/coding-style.html#spaces
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
I run ``sudo make`` and then visualized the man page with
``man 3 queue``, and the contents looked good.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
In C89 strtod returns zero on underflow, but since C99 it can return
non-zero. This means the strtod.3 page contradicts all recent C and
POSIX standards. Both C and POSIX say "smallest normalized positive
number", but for consistency with HUGE_VAL, HUGE_VALF and HUGE_VALL
this patch uses the constants for those numbers.
Also slightly improve the presentation of return values for overflow.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The description of hexadecimal floating-point output is missing a
character describing the exponent. The guarantee of at least one digit
in the exponent is present in both C99 and POSIX.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This header is used inconsistently -- man pages are UTF-8 encoded
but not setting this marker. It's only respected by the man-db
package, and seems a bit anachronistic at this point when UTF-8
is the standard default nowadays.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
There was code containing ``CIRCLEQ_*`` in the examples for ``TAILQ_*``. It was introduced by accident in commit ``041abbe``.
From 0c9dfbe9b1ce1130e9a92d1a16fbecd4a08bbe29 Mon Sep 17 00:00:00 2001
From: Alejandro Colomar <colomar.6.4.3@gmail.com>
Date: Wed, 12 Aug 2020 09:11:27 +0200
Subject: [PATCH] queue.3: Remove wrong code from example
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
A naked tilde ("~") renders poorly in PDF. Instead use "\(ti",
which renders better in a PDF, and produces the same glyph
when rendering on a terminal.
Reported-by: Geoff Clare <gwc@opengroup.org>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
===========
DESCRIPTION
===========
I'm documenting ``CIRCLEQ_*`` macros in queue.3. While writing
this, I noticed that the documentation for some types of
queues/lists talked about swapping contents of two lists, but only
for some of them. I then found that those macros (``*_SWAP``)
don't exist in my system (Debian), but exist in BSD, and I also
found that a previous commit (6559169cac) commented out a lot of
the *_SWAP macros documentation, but not all, and the reason was
that they were not present on glibc.
I checked that I didn't have any of the *_SWAP macros on my glibc,
so I think this is probably that the commit simply forgot to
comment some of
them.
=======
TESTING
=======
I did ``sudo make`` and then visualized the man page with
``man 3 queue``, and the changes looked good.
I also noticed that the subsection ``Tail queue example`` contents
were wrong, as they contained calls to CIRCLEQ_* macros. I will
address that in a future patch, before I submit the patch
documenting CIRCLEQ_*.
Signed-off-by: Alejandro Colomar <colomar.6.4.3@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Historically, a comment of the following form at the top of a
manual page was used to indicate too man(1) that the use of tbl(1)
was required in order to process tables:
'\" t
However, at least as far back as 2001 (according to Branden),
man-db's man(1) automatically uses tbl(1) as needed, rendering
this comment unnecessary. And indeed many existing pages in
man-pages that have tables don't have this comment at the top of
the file. So, drop the comment from those files where it is
present.
[mtk: completely rewrote commit message]
Reported-by: G. Branden Robinson <g.branden.robinson@gmail.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The \" comment produces blank lines. Use the .\" that the vast
majority of the codebase uses instead.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Clarify that it is recursive read locks on the read-write lock
that make it difficult to implement
PTHREAD_RWLOCK_PREFER_WRITER_NP.
Update the libc-alpha URL and provide the URL to the POSIX wording
that is quoted in the comment.
Reported-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Carlos O'Donell <carlos@redhat.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Change '--' to '\-\-' for options and '--' between words to '\(em'
(em-dash).
Signed-off-by: Bjarni Ingi Gislason <bjarniig@rhi.hi.is>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Change '-' to '\-' for the prefix of names to indicate an option.
Signed-off-by: Bjarni Ingi Gislason <bjarniig@rhi.hi.is>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The host ID might once have been intended to be globally unique,
but that turned out not to feasible.
Reported-by: Rich Felker <dalias@libc.org>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Remove superfluous paragraph macros.
Remove request ".br" if it precedes a line, that begins with a
space, as such lines automatically cause a break.
There is no change in the output from "nroff" and "groff".
###
Examples of warnings from "mandoc -Tlint":
mandoc: bindresvport.3:41:2: WARNING: skipping paragraph macro: PP after SH
mandoc: crypt.3:228:2: WARNING: skipping paragraph macro: PP empty
mandoc: dlinfo.3:151:2: WARNING: skipping paragraph macro: IP empty
mandoc: exec.3:86:2: WARNING: skipping paragraph macro: PP after SS
mandoc: getsubopt.3:45:2: WARNING: skipping paragraph macro: br before text line with leading blank
Signed-off-by: Bjarni Ingi Gislason <bjarniig@rhi.hi.is>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
These are all links that were created several years ago, mainly
when pages were migrated to different sections, in order to
allow the 'man' commands using the old section numbers to work.
However, the plan was always to eventually remove them, after
allowing people who cared to get used to the new section numbers.
Now, after 5+ years in each case, it's time to remove
these links.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
I believe new users should be discouraged from using atoi() and
that its disadvantages should be explained.
I added the information that 0 is returned on error - although C
standard and POSIX say that "If the value of the result cannot be
represented, the behavior is undefined." there are some
interpretations that 0 has to be returned
https://stackoverflow.com/questions/38393162/what-can-i-assume-about-the-behaviour-of-atoi-on-error
and this is also what happens in practice with glibc, musl and
uClibc.
Signed-off-by: Arkadiusz Drabczyk <arkadiusz@drabczyk.org>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Output is from: test-groff -b -e -mandoc -T utf8 -rF0 -t -w w -z
[ "test-groff" is a developmental version of "groff" ]
There is no change in the output of "nroff" and "groff".
####
troff: <fts.3>:50: warning: trailing space
####
troff: <getgrnam.3>:175: warning: trailing space
####
troff: <getpwnam.3>:181: warning: trailing space
####
troff: <rcmd.3>:52: warning: trailing space
troff: <rcmd.3>:57: warning: trailing space
troff: <rcmd.3>:60: warning: trailing space
troff: <rcmd.3>:63: warning: trailing space
troff: <rcmd.3>:69: warning: trailing space
troff: <rcmd.3>:73: warning: trailing space
####
troff: <rexec.3>:48: warning: trailing space
troff: <rexec.3>:51: warning: trailing space
####
troff: <sem_open.3>:36: warning: trailing space
Signed-off-by: Bjarni Ingi Gislason <bjarniig@rhi.hi.is>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
RAND_MAX is for rand(3). POSIX fixes random()'s range at 2^31-1;
RAND_MAX may be smaller on some platforms (even though with glibc
or musl on Linux they are the same).
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
In the few pages where this heading (which is "nonstandard" within
man-pages) is used, it always immediately follows CONFORMING TO
and generally contains information related to standards. Remove
the section heading, thus incorporating AVAILABILITY into
CONFORMING TO.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
EXAMPLES appears to be the wider majority usage across various
projects' manual pages, and is also what is used in the POSIX
manual pages.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The fact that an FE_UNDERFLOW exception is not raised for
"Range error: result underflow" is intended behavior.
See https://www.sourceware.org/bugzilla/show_bug.cgi?id=6806.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The function make_message illustrates how to use vsnprintf to
determine the required amount of memory for a specific format and
its arguments.
If make_message is called with a format which will use exactly
INT_MAX characters (excluding '\0'), then the size++ calculation
will overflow the signed integer "size", which is an undefined
behaviour in C.
Since malloc and vsnprintf rightfully take a size_t argument, I
decided to use a size_t variable for size calculation. Therefore,
this patched code uses variables of the same data types as
expected by function arguments.
Proof of concept (tested on Linux/glibc amd64):
int main() { make_message("%647s%2147483000s", "", ""); }
If the code is compiled with address sanitizer (gcc
-fsanitize=address) you can see the following line, assuming that
a signed integer overflow simply leads to INT_MIN:
==3094==WARNING: AddressSanitizer failed to allocate 0xffffffff80000000 bytes
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Remove the text ("rare)" after a note from Vincent Lefèvre:
Subject: [Bug math/13932] dbl-64 pow unexpectedly slow for some inputs
Date: Sat, 23 May 2020 21:31:52 +0000
From: vincent-srcware at vinc17 dot net <sourceware-bugzilla@sourceware.org>
To: mtk.manpages@gmail.comhttps://sourceware.org/bugzilla/show_bug.cgi?id=13932
--- Comment #26 from Vincent Lefèvre <vincent-srcware at vinc17 dot net> ---
(In reply to Michael Kerrisk from comment #25)
> Fix documented for man-pages-5.07.
[...]
> -On 64-bits,
> +Before glibc 2.28,
> .\"
> .\" https://sourceware.org/bugzilla/show_bug.cgi?id=13932
> +on some architectures (e.g., x86-64)
> .BR pow ()
> may be more than 10,000 times slower for some (rare) inputs
> than for other nearby inputs.
[...]
The problematic values are uncommon, but not so rare, in the sense
that they are close to simple values, i.e. are likely to occur in
practice. An example given above: pow(0.999999999999999889, 1.5)
1 and 1.5 are very simple values, which are more likely to occur
in practice than some fixed random value. Then it suffices to have
a small rounding error on 1...
For instance, this is very different from hard-to-round cases of
exp, which are also very slow IMHO, but unless one writes a
specific program for them, no-one should notice the slowness
because such a case would typically occur only once among billions
(I don't remember the accuracy before the slowest path in this
library).
Reported-by: Vincent Lefèvre <vincent-srcware@vinc17.net>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Avoid implying that use of IFUNC is the only way to produce a
symbol with NULL value. Give more scenarios how a symbol may get
NULL value, but explain that in those scenarios dlsym() will fail
with Glibc's ld.so due to an implementation inconsistency.
Signed-off-by: Alexander Monakov <amonakov@ispras.ru>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This is a sequel to commit baf17bc4f2, addressing the
issues with missing commas in the middle of SEE ALSO lists that
emerged since.
The awk script from the original commit was not working and had to
be slightly modified (s/["]SEE ALSO["]/"?SEE ALSO/), otherwise it
works like a charm. Here's the fixed script and its output just
before this commit:
for f in man*/*; do
awk '
/^.SH "?SEE ALSO/ {
sa=1; print "== " FILENAME " =="; print; next
}
/^\.(PP|SH)/ {
sa=0; no=0; next
}
/^\.BR/ {
if (sa==1) {
print;
if (no == 1)
print "Missing comma in " FILENAME " +" FNR-1; no=0
}
}
/^\.BR .*)$/ {
if (sa==1)
no=1;
next
}
/\.\\"/ {next}
/.*/ {
if (sa==1) {
print; next
}
}
' $f; done | grep Missing
Missing comma in man1/memusage.1 +272
Missing comma in man2/adjtimex.2 +597
Missing comma in man2/adjtimex.2 +598
Missing comma in man2/mkdir.2 +252
Missing comma in man2/sigaction.2 +1045
Missing comma in man2/sigaction.2 +1047
Missing comma in man3/mbsnrtowcs.3 +198
Missing comma in man3/ntp_gettime.3 +142
Missing comma in man3/strcmp.3 +219
Missing comma in man3/strtol.3 +302
Missing comma in man3/wcstombs.3 +120
Missing comma in man7/user_namespaces.7 +1378
Missing comma in man7/xattr.7 +198
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
By way of a hint that the file descriptor returned by dirfd()
could usefully be fed to the *at() APIs.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Both functions behave the same wrt return value, no need to describe
them separately.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The Linux man page for ptsname_r, when describing the behaviour
in the error case, is
- not consistent with the future POSIX standard (POSIX Issue 8).
- not consistent with musl libc.
Find attached a patch to
- keep it consistent with what glibc does,
- make it consistent with musl libc,
- make it consistent with the future POSIX standard (POSIX
Issue 8).
Details:
glibc's implementation of ptsname_r, when it fails, returns the
error code as return value AND sets errno. See
https://sourceware.org/git/?p=glibc.git;a=blob;f=login/ptsname.chttps://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/mach/hurd/ptsname.chttps://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/unix/sysv/linux/ptsname.c
musl's implementation of ptsname_r, when it fails, returns the error code
but does NOT set errno. See
https://git.musl-libc.org/cgit/musl/tree/src/misc/pty.c
The proposal to add ptsname_r to POSIX, with text
"If successful, the ptsname_r( ) function shall return zero.
Otherwise, an error number shall be returned to indicate the
error."
has been accepted for inclusion in POSIX Issue 8.
http://austingroupbugs.net/view.php?id=508
Therefore a portable program should look at the return value from
ptsname_r, NOT the errno value. The current text in the man page
suggests to look at the errno value, which is wrong (because of
musl libc) and not future-proof (because of future POSIX).
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Redundant because this is a Section 3 page, and the
text also describes the implementation in glibc.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Since glibc 2.26, posix_spawn (2) function accepts the
POSIX_SPAWN_SETSID flag. This flag has been accepted by POSIX and
should be added to the next major revision. The current support
can be enabled with _GNU_SOURCE.
Upstream commit in glibc.git:
daeb1fa2e1 [BZ 21340] add support for POSIX_SPAWN_SETSID
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Signed-off-by: Olivier Gayot <olivier.gayot@sigexec.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The implementation of the fork() step in posix_spawn(2) relies on
either fork(2), vfork(2) or clone(2) depending on the version of
the glibc and the arguments passed to posix_spawn(2).
It is sometimes ambiguous whether, when we are mentioning
"fork(2)", we are referring to the fork() step or the actual
fork(2) syscall.
This patch hopefully avoids the ambiguity by replacing confusing
occurrences by "the xxx() step" where appropriate.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Signed-off-by: Olivier Gayot <olivier.gayot@sigexec.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Added a few lines about POSIX_SPAWN_USEVFORK so that it appears
clearly that since glibc 2.24, the flag has no effect.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Signed-off-by: Olivier Gayot <olivier.gayot@sigexec.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Since glibc 2.24, the use of posix_spawn (2) makes an
unconditional call to clone(CLONE_VM | CLONE_VFORK ...) rather
than relying on fork (2) or vfork (2).
As a consequence, the statements regarding the use of the flag
POSIX_SPAWN_USEVFORK and how the function decides whether it
should use fork (2) or vfork (2) are obsolete since glibc 2.24.
This patch makes a distinction in the manual page between glibc
2.24 and older versions.
Upstream commit in glibc.git:
9ff72da471 posix: New Linux posix_spawn{p} implementation
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Signed-off-by: Olivier Gayot <olivier.gayot@sigexec.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
A year cannot only begin with week number 53 of the previous year but
also with week number 52. Year 2011 is an example for this case, as
can be easily seen with GNU date:
$ date -d "jan 1 2011" "+%c %V %G"
Sat Jan 1 00:00:00 2011 52 2010
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Reported-by: Andrew Micallef <andrew.micallef@live.com.au>
Reported-by: Walter Harms <wharms@bfs.de>
Reviewed-by: Andrew Micallef <andrew.micallef@live.com.au>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
* man3/strftime.3 (%C): Describe the meaning of %EC conversion
specification.
(%E): Mention the concept of "era" in description.
(%O): Mention that alternative format is related to numeric
representation.
(%y): Describe the meaning of %Ey conversion specification.
(%Y): Describe the meaning of %EY conversion specification.
(.SH DESCRIPTION): Mention that the behaviour of %E modifier is governed
by ERA locale element and provide ja_JP locale as an example.
Signed-off-by: Eugene Syromyatnikov <evgsyr@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
As it wasn't clear before where this kind of information can be
obtained from.
* man3/strftime.3 (%a, %A, %b, %B, %c, %p, %r, %x, %X): Add information
about the locale elements that can be used to retrieve the relevant
information using nl_langinfo() library call.
Signed-off-by: Eugene Syromyatnikov <evgsyr@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
In many cases, these don't improve readability, and (when stacked)
they sometimes have the side effect of sometimes forcing text
to be justified within a narrow column range.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
One might be tempted to think that realloc() always requests a new
allocation before moving the contents over (at least in the case
where the new size is bigger than the original). This is not the
case; for example, on my system the following program:
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
int main(int argc, char *argv[])
{
void *x = malloc(15);
void *y = malloc(32);
printf("x = %p\n", x);
printf("y = %p\n", y);
printf("usable_size(x) = %lu\n", malloc_usable_size(x));
void *z = realloc(x, 24);
printf("z = %p\n", z);
return 0;
}
prints:
x = 0x1b3a010
y = 0x1b3a030
usable_size(x) = 24
z = 0x1b3a010
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Admittedly, the POSIX specification for exit() also uses octal.
However, 0xFF immediately indicates the lowest 8 bits to me
whereas I had to think a bit about the octal mask.
Cowritten-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
From an email by Rich Felker:
It came to my attention while reviewing possible breakage with
move to 64-bit time_t that some applications are dereferencing
data in socket control messages (particularly SCM_TIMESTAMP*)
in-place as the message type, rather than memcpy'ing it to
appropriate storage. This necessarily does not work and is not
supportable if the message contains data with greater alignment
requirement than the header. In particular, on 32-bit archs,
cmsghdr has size 12 and alignment 4, but struct timeval and
timespec may have alignment requirement 8.
I found at least ptpd, socat, and ssmping doing this via Debian
Code Search:
https://sources.debian.org/src/ptpd/2.3.1-debian1-4/src/dep/net.c/?hl=1578#L1578https://sources.debian.org/src/socat/1.7.3.3-2/xio-socket.c/?hl=1839#L1839https://sources.debian.org/src/ssmping/0.9.1-3/ssmpngcl.c/?hl=307#L307
and I suspect there are a good deal more out there. On most archs
they won't break, or will visibly break with SIGBUS, but in theory
it's possible that they silently read wrong data and this might
happen on some older and more tiny-embedded-oriented archs.
I think it's clear to someone who understands alignment and who's
thought about it that applications just can't do this, but it
doesn't seem to be documented, and an example in cmsg(3) even
shows access to int payload via *(int *)CMSG_DATA(cmsg) (of course
int is safe because its alignment is <= header alignment, but this
is not mentioned).
Could we add text, and perhaps change the example, to indicate
that in general memcpy needs to be used to copy the payload
to/from a suitable object?
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This patch is a minor wording fix in getcwd.3 that changes "In the case getcwd()" to "In the case of getcwd()". This patch should apply cleanly to the master branch of the git repository.
Regards,
Mike Salvatore
From 3b68ad225dbaada2b1b55153dc57807b04531cd6 Mon Sep 17 00:00:00 2001
From: Mike Salvatore <mike.salvatore@canonical.com>
Date: Thu, 16 Jan 2020 16:08:08 -0500
Subject: [PATCH] getcwd.3: wfix
Signed-off-by: Mike Salvatore <mike.salvatore@canonical.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Fixes: d8d701003 ("malloc.3: Since glibc 2.29, realloc() is exposed by
defining _DEFAULT_SOURCE")
Signed-off-by: Petr Vorel <pvorel@suse.cz>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The glibc implementation of getpt has actually never been setting
O_NOCTTY when opening /dev/ptmx or BSD ptys.
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
In a recent conversation with Mathieu Desnoyers I was reminded
that we haven't written up anything about how deferred
cancellation and asynchronous signal handlers interact. Mathieu
ran into some of this behaviour and I promised to improve the
documentation in this area to point out the potential pitfall.
Thoughts?
8< --- 8< --- 8<
In pthread_setcancelstate.3, pthreads.7, and signal-safety.7 we
describe that if you have an asynchronous signal nesting over a
deferred cancellation region that any cancellation point in the
signal handler may trigger a cancellation that will behave
as-if it was an asynchronous cancellation. This asynchronous
cancellation may have unexpected effects on the consistency of
the application. Therefore care should be taken with asynchronous
signals and deferred cancellation.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Add entries for the new cache geometry values of the auxiliary
vector that got included in the kernel.
Signed-off-by: Raphael Moreira Zinsly <rzinsly@linux.vnet.ibm.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This requirement on the first digit with the %e format comes from
the ISO C standard. It ensures that all the digits in the output are
significant and forbids output with a precision less than requested.
Signed-off-by: Vincent Lefevre <vincent@vinc17.net>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Michael Kerrisk