This wraps chown(2) but takes the user/owner and group as strings.
It's a little long winded as it uses the thread safe versions of
getpwnam()/getgrname() which require a little more work.
This function will be used by the following commit that allows to set
the permissions of the Unix domain control socket.
We need to cast uid & gid to long in the call to nxt_thread_log_alert()
to appease clang-ast as it's adamant that uid/gid are unsigned ints, but
chown(2) takes -1 for these values to indicate don't change this item,
and it'd be nice to show them in the error message.
Note that getpwnam()/getgrname() don't define "not found" as an error as
per their man page
The formulation given above under "RETURN VALUE" is from POSIX.1-2001.
It does not call "not found" an error, and hence does not specify what
value errno might have in this situation. But that makes it impossible
to recognize errors. One might argue that according to POSIX errno
should be left unchanged if an entry is not found. Experiments on var‐
ious UNIX-like systems show that lots of different values occur in this
situation: 0, ENOENT, EBADF, ESRCH, EWOULDBLOCK, EPERM, and probably
others.
Thus if we log an error from these functions we can end up with the
slightly humorous error message
2024/02/12 15:15:12 [alert] 99404#99404 getpwnam_r("noddy", ...) failed (0: Success) (User not found) while creating listening socket on unix:/opt/unit/control.unit.sock
Reviewed-by: Zhidao Hong <z.hong@f5.com>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
This is analogous to the nxt_file_stderr() function and will be used in
a subsequent commit.
This function redirects stdout to a given file descriptor.
Reviewed-by: Alejandro Colomar <alx@nginx.com>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
Add simple wrapper functions for fopen(3) and fclose(3) that are
somewhat akin to the nxt_file_open() and nxt_file_close() wrappers that
log errors.
Suggested-by: Alejandro Colomar <alx@nginx.com>
Reviewed-by: Alejandro Colomar <alx@nginx.com>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>
We had a mix of styles for declaring function-like macros:
Style A:
#define \
foo() \
do { \
... \
} while (0)
Style B:
#define foo() \
do { \
... \
} while (0)
We had a similar number of occurences of each style:
$ grep -rnI '^\w*(.*\\' | wc -l
244
$ grep -rn 'define.*(.*)' | wc -l
239
(Those regexes aren't perfect, but a very decent approximation.)
Real examples:
$ find src -type f | xargs sed -n '/^nxt_double_is_zero/,/^$/p'
nxt_double_is_zero(f) \
(fabs(f) <= FLT_EPSILON)
$ find src -type f | xargs sed -n '/define nxt_http_field_set/,/^$/p'
#define nxt_http_field_set(_field, _name, _value) \
do { \
(_field)->name_length = nxt_length(_name); \
(_field)->value_length = nxt_length(_value); \
(_field)->name = (u_char *) _name; \
(_field)->value = (u_char *) _value; \
} while (0)
I'd like to standardize on a single style for them, and IMO,
having the identifier in the same line as #define is a better
option for the following reasons:
- Programmers are used to `#define foo() ...` (readability).
- One less line of code.
- The program for finding them is really simple (see below).
function grep_ngx_func()
{
if (($# != 1)); then
>&2 echo "Usage: ${FUNCNAME[0]} <func>";
return 1;
fi;
find src -type f \
| grep '\.[ch]$' \
| xargs grep -l "$1" \
| sort \
| xargs pcregrep -Mn "(?s)^\$[\w\s*]+?^$1\(.*?^}";
find src -type f \
| grep '\.[ch]$' \
| xargs grep -l "$1" \
| sort \
| xargs pcregrep -Mn "(?s)define $1\(.*?^$" \
| sed -E '1s/^[^:]+:[0-9]+:/&\n\n/';
}
$ grep_ngx_func
Usage: grep_ngx_func <func>
$ grep_ngx_func nxt_http_field_set
src/nxt_http.h:98:
#define nxt_http_field_set(_field, _name, _value) \
do { \
(_field)->name_length = nxt_length(_name); \
(_field)->value_length = nxt_length(_value); \
(_field)->name = (u_char *) _name; \
(_field)->value = (u_char *) _value; \
} while (0)
$ grep_ngx_func nxt_sprintf
src/nxt_sprintf.c:56:
u_char * nxt_cdecl
nxt_sprintf(u_char *buf, u_char *end, const char *fmt, ...)
{
u_char *p;
va_list args;
va_start(args, fmt);
p = nxt_vsprintf(buf, end, fmt, args);
va_end(args);
return p;
}
................
Scripted change:
................
$ find src -type f \
| grep '\.[ch]$' \
| xargs sed -i '/define *\\$/{N;s/ *\\\n/ /;s/ //}'
