Add some subsection (.SS) headings and paragraph breaks in
DESCRIPTION, to make the page more easily readable.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
glibc has tightened up its rules for replacing the memory
allocator. I went through the malloc man page and looked for how
it documented malloc() and related functions, and fixed
discrepancies with glibc malloc() documentation and/or
implementation. I also reorganized the portability discussion so
that portability issues can be seen more clearly.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Zero in this case refers to literal constant 0 and not symbolic
constant B0.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
The previous wording wasn't very explicit, leaving room for
believing that 'errno' may be 0 after returning EAI_SYSTEM.
Use a wording similar to other pages, for added consistency.
[mtk: edited commit message title; also, POSIX notes that
'errno' is set in this case.]
Reported-by: Cristian Morales Vega <christian.morales.vega@gmail.com>
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
These pages split out extra errors for some APIs into a separate
list. Probably, the pages are easier to ready if all errors are
combined into a single list.
Note that there still remain a few pages where the errors are
listed separately for different APIs. For the moment, it seems
best to leave those pages as is, since the error lists are
largely distinct in those pages.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Make the description of the EBADF error for invalid 'dirfd' more
uniform. In particular, note that the error only occurs when the
pathname is relative, and that it occurs when the 'dirfd' is
neither valid *nor* has the value AT_FDCWD.
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
From an email conversation with Alexis:
Hello Alexis,
On 8/6/21 7:06 PM, Alexis Wilke wrote:
> Hi guys,
>
> The pthread_setname_np(3) manual page has an example where the second
> argument is used to get a size of the thread name.
>
> https://man7.org/linux/man-pages/man3/pthread_setname_np.3.html#EXAMPLES
>
> The current code:
>
> rc = pthread_getname_np(thread, thread_name,
> (argc > 2) ? atoi(argv[1]) : NAMELEN);
>
> The suggested code:
>
> rc = pthread_getname_np(thread, thread_name,
> (argc > 2) ? atoi(argv[2]) : NAMELEN);
I agree that there's a problem, but I think we could go even simpler:
rc = pthread_getname_np(thread, thread_name, NAMELEN);
> I'm thinking that maybe the author meant to compute the length like so:
>
> rc = pthread_getname_np(thread, thread_name,
> (argc > 2) ? strlen(argv[1]) + 1 :
> NAMELEN);
>
> But I think that the atoi() points to using argv[2] as a number
> representing the length.
>
> (Of course, it should be tested against NAMELEN as a maximum, but I
> understand that examples do not always show how to verify each possible
> error).
I imagine that the author's intention was to allow the user to do
experiments where argv[2] specified a number less than NAMELEN,
in order to see the resulting ERANGE error. But, that experiment
is of limited value, and complicates the code unnecessarily, IMO,
so that's why I made the change above.
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
Reported-by: Alexis Wilke <alexis@m2osw.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: James O. D. Hunt <jamesodhunt@gmail.com>
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Explain that `optstring` cannot contain a semi-colon (`;`)
character.
[mtk: verified with a small test program; see also posix/getopt.c
in the glibc sources:
if (temp == NULL || c == ':' || c == ';')
{
if (print_errors)
fprintf (stderr, _("%s: invalid option -- '%c'\n"), argv[0], c);
d->optopt = c;
return '?';
}
]
Also explain that `optstring` can include `+` as an option
character, possibly in addition to that character being used as
the first character in `optstring` to denote `POSIXLY_CORRECT`
behaviour.
[mtk: verified with a small test program.]
Test program below. Example runs:
$ ./a.out -+
opt = 43 (+); optind = 2
Got plus
$ ./a.out -';'
./a.out: invalid option -- ';'
opt = 63 (?); optind = 2; optopt = 59 (;)
Unrecognized option (-;)
Usage: ./a.out [-p arg] [-x]
Signed-off-by: James O. D. Hunt <jamesodhunt@gmail.com>
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---8x---
#include <ctype.h>
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#define printable(ch) (isprint((unsigned char) ch) ? ch : '#')
static void /* Print "usage" message and exit */
usageError(char *progName, char *msg, int opt)
{
if (msg != NULL && opt != 0)
fprintf(stderr, "%s (-%c)\n", msg, printable(opt));
fprintf(stderr, "Usage: %s [-p arg] [-x]\n", progName);
exit(EXIT_FAILURE);
}
int
main(int argc, char *argv[])
{
int opt, xfnd;
char *pstr;
xfnd = 0;
pstr = NULL;
while ((opt = getopt(argc, argv, "p:x+;")) != -1) {
printf("opt =%3d (%c); optind = %d", opt, printable(opt), optind);
if (opt == '?' || opt == ':')
printf("; optopt =%3d (%c)", optopt, printable(optopt));
printf("\n");
switch (opt) {
case 'p': pstr = optarg; break;
case 'x': xfnd++; break;
case ';': printf("Got semicolon\n"); break;
case '+': printf("Got plus\n"); break;
case ':': usageError(argv[0], "Missing argument", optopt);
case '?': usageError(argv[0], "Unrecognized option", optopt);
default:
printf("Unexpected case in switch()\n");
exit(EXIT_FAILURE);
}
}
if (xfnd != 0)
printf("-x was specified (count=%d)\n", xfnd);
if (pstr != NULL)
printf("-p was specified with the value \"%s\"\n", pstr);
if (optind < argc)
printf("First nonoption argument is \"%s\" at argv[%d]\n",
argv[optind], optind);
exit(EXIT_SUCCESS);
}
SPARC is special, it does not have Bnnn constants for baud rates above
2000000. Instead it defines 4 Bnnn constants with smaller baud rates.
This difference between SPARC and non-SPARC architectures is present in
both glibc API (termios.h) and also kernel ioctl API (asm/termbits.h).
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Format variable parts of words referring to a group of identifiers
in italics, following groff_man(7) recommendations.
Also srcfix surrounding uses of \f escape sequences to use macros
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
These baud-rate macro constants are defined in bits/termios.h and are
already supported.
Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
With a simple backslash, '\0' ended up as ' ' in the man output.
Reported-by: Štěpán Němec <stepnem@gmail.com>
Signed-off-by: Alejandro Colomar <alx.manpages@gmail.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Michael Kerrisk