0,0 → 1,85 |
/* GNU variant of strerror_r. */ |
/* |
FUNCTION |
<<strerror_r>>---convert error number to string and copy to buffer |
|
INDEX |
strerror_r |
|
ANSI_SYNOPSIS |
#include <string.h> |
#ifdef _GNU_SOURCE |
char *strerror_r(int <[errnum]>, char *<[buffer]>, size_t <[n]>); |
#else |
int strerror_r(int <[errnum]>, char *<[buffer]>, size_t <[n]>); |
#endif |
|
TRAD_SYNOPSIS |
#include <string.h> |
char *strerror_r(<[errnum]>, <[buffer]>, <[n]>) |
int <[errnum]>; |
char *<[buffer]>; |
size_t <[n]>; |
|
DESCRIPTION |
<<strerror_r>> converts the error number <[errnum]> into a |
string and copies the result into the supplied <[buffer]> for |
a length up to <[n]>, including the NUL terminator. The value of |
<[errnum]> is usually a copy of <<errno>>. If <<errnum>> is not a known |
error number, the result is the empty string. |
|
See <<strerror>> for how strings are mapped to <<errnum>>. |
|
RETURNS |
There are two variants: the GNU version always returns a NUL-terminated |
string, which is <[buffer]> if all went well, but which is another |
pointer if <[n]> was too small (leaving <[buffer]> untouched). If the |
return is not <[buffer]>, your application must not modify that string. |
The POSIX version returns 0 on success, <[EINVAL]> if <<errnum>> was not |
recognized, and <[ERANGE]> if <[n]> was too small. The variant chosen |
depends on macros that you define before inclusion of <<string.h>>. |
|
PORTABILITY |
<<strerror_r>> with a <[char *]> result is a GNU extension. |
<<strerror_r>> with an <[int]> result is required by POSIX 2001. |
This function is compliant only if <<_user_strerror>> is not provided, |
or if it is thread-safe and uses separate storage according to whether |
the second argument of that function is non-zero. For more details |
on <<_user_strerror>>, see the <<strerror>> documentation. |
|
POSIX states that the contents of <[buf]> are unspecified on error, |
although this implementation guarantees a NUL-terminated string for |
all except <[n]> of 0. |
|
POSIX recommends that unknown <[errnum]> result in a message including |
that value, however it is not a requirement and this implementation |
provides only an empty string (unless you provide <<_user_strerror>>). |
POSIX also recommends that unknown <[errnum]> fail with EINVAL even |
when providing such a message, however it is not a requirement and |
this implementation will return success if <<_user_strerror>> provided |
a non-empty alternate string without assigning into its third argument. |
|
<<strerror_r>> requires no supporting OS subroutines. |
|
*/ |
|
#undef __STRICT_ANSI__ |
#define _GNU_SOURCE |
#include <errno.h> |
#include <string.h> |
#undef strerror_r |
|
/* For backwards-compatible linking, this must be the GNU signature; |
see xpg_strerror_r.c for the POSIX version. */ |
char * |
_DEFUN (strerror_r, (errnum, buffer, n), |
int errnum _AND |
char *buffer _AND |
size_t n) |
{ |
char *error = _strerror_r (_REENT, errnum, 1, NULL); |
|
if (strlen (error) >= n) |
return error; |
return strcpy (buffer, error); |
} |