diff options
Diffstat (limited to 'newlib/libc/string/strerror_r.c')
| -rw-r--r-- | newlib/libc/string/strerror_r.c | 46 |
1 files changed, 38 insertions, 8 deletions
diff --git a/newlib/libc/string/strerror_r.c b/newlib/libc/string/strerror_r.c index be5358f3e..c2057b7f0 100644 --- a/newlib/libc/string/strerror_r.c +++ b/newlib/libc/string/strerror_r.c @@ -1,3 +1,4 @@ +/* GNU variant of strerror_r. */ /* FUNCTION <<strerror_r>>---convert error number to string and copy to buffer @@ -7,7 +8,11 @@ INDEX 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> @@ -19,35 +24,60 @@ TRAD_SYNOPSIS 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 +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 -This function returns a pointer to a string. Your application must -not modify that string. +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>> is a GNU extension. +<<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 does not modify <<errno>>. + +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. <<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; - error = strerror (errnum); + char *error = strerror (errnum); - return strncpy (buffer, (const char *)error, n); + if (strlen (error) >= n) + return error; + return strcpy (buffer, error); } |