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/* strerror_r.c --- POSIX compatible system error routine
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Copyright (C) 2010-2011 Free Software Foundation, Inc.
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>. */
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/* Written by Bruno Haible <bruno@clisp.org>, 2010. */
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/* Enable declaration of sys_nerr and sys_errlist in <errno.h> on NetBSD. */
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#define _NETBSD_SOURCE 1
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#include "strerror-override.h"
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#if (__GLIBC__ >= 2 || defined __UCLIBC__ || defined __CYGWIN__) && HAVE___XPG_STRERROR_R /* glibc >= 2.3.4, cygwin >= 1.7.9 */
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# define USE_XPG_STRERROR_R 1
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#elif HAVE_DECL_STRERROR_R && !(__GLIBC__ >= 2 || defined __UCLIBC__ || defined __CYGWIN__)
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/* The system's strerror_r function is OK, except that its third argument
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is 'int', not 'size_t', or its return type is wrong. */
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# define USE_SYSTEM_STRERROR_R 1
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#else /* (__GLIBC__ >= 2 || defined __UCLIBC__ || defined __CYGWIN__ ? !HAVE___XPG_STRERROR_R : !HAVE_DECL_STRERROR_R) */
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/* Use the system's strerror(). Exclude glibc and cygwin because the
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system strerror_r has the wrong return type, and cygwin 1.7.9
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strerror_r clobbers strerror. */
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# define USE_SYSTEM_STRERROR 1
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# if defined __NetBSD__ || defined __hpux || ((defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__) || defined __sgi || (defined __sun && !defined _LP64) || defined __CYGWIN__
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/* No locking needed. */
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/* Get catgets internationalization functions. */
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# include <nl_types.h>
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/* Get sys_nerr, sys_errlist on HP-UX (otherwise only declared in C++ mode).
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Get sys_nerr, sys_errlist on IRIX (otherwise only declared with _SGIAPI). */
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# if defined __hpux || defined __sgi
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extern char *sys_errlist[];
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/* Get sys_nerr on Solaris. */
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# if defined __sun && !defined _LP64
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# include "glthread/lock.h"
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/* This lock protects the buffer returned by strerror(). We assume that
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no other uses of strerror() exist in the program. */
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gl_lock_define_initialized(static, strerror_lock)
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/* Copy as much of MSG into BUF as possible, without corrupting errno.
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Return 0 if MSG fit in BUFLEN, otherwise return ERANGE. */
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safe_copy (char *buf, size_t buflen, const char *msg)
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size_t len = strlen (msg);
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/* Although POSIX allows memcpy() to corrupt errno, we don't
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know of any implementation where this is a real problem. */
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memcpy (buf, msg, len + 1);
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memcpy (buf, msg, buflen - 1);
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buf[buflen - 1] = '\0';
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strerror_r (int errnum, char *buf, size_t buflen)
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/* Filter this out now, so that rest of this replacement knows that
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there is room for a non-empty message and trailing NUL. */
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/* Check for gnulib overrides. */
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char const *msg = strerror_override (errnum);
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return safe_copy (buf, buflen, msg);
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int saved_errno = errno;
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#if USE_XPG_STRERROR_R
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extern int __xpg_strerror_r (int errnum, char *buf, size_t buflen);
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ret = __xpg_strerror_r (errnum, buf, buflen);
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/* glibc 2.13 would not touch buf on err, so we have to fall
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back to GNU strerror_r which always returns a thread-safe
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untruncated string to (partially) copy into our buf. */
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safe_copy (buf, buflen, strerror_r (errnum, buf, buflen));
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#elif USE_SYSTEM_STRERROR_R
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if (buflen > INT_MAX)
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/* On HP-UX 11.31, strerror_r always fails when buflen < 80; it
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also fails to change buf on EINVAL. */
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if (buflen < sizeof stackbuf)
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ret = strerror_r (errnum, stackbuf, sizeof stackbuf);
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ret = safe_copy (buf, buflen, stackbuf);
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ret = strerror_r (errnum, buf, buflen);
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ret = strerror_r (errnum, buf, buflen);
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/* Some old implementations may return (-1, EINVAL) instead of EINVAL. */
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/* AIX returns 0 rather than ERANGE when truncating strings; try
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again until we are sure we got the entire string. */
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if (!ret && strlen (buf) == buflen - 1)
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char stackbuf[STACKBUF_LEN];
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strerror_r (errnum, stackbuf, sizeof stackbuf);
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len = strlen (stackbuf);
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/* STACKBUF_LEN should have been large enough. */
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if (len + 1 == sizeof stackbuf)
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/* Solaris 10 does not populate buf on ERANGE. OpenBSD 4.7
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truncates early on ERANGE rather than return a partial integer.
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We prefer the maximal string. We set buf[0] earlier, and we
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know of no implementation that modifies buf to be an
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unterminated string, so this strlen should be portable in
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practice (rather than pulling in a safer strnlen). */
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if (ret == ERANGE && strlen (buf) < buflen - 1)
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char stackbuf[STACKBUF_LEN];
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/* STACKBUF_LEN should have been large enough. */
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if (strerror_r (errnum, stackbuf, sizeof stackbuf) == ERANGE)
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safe_copy (buf, buflen, stackbuf);
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#else /* USE_SYSTEM_STRERROR */
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/* Try to do what strerror (errnum) does, but without clobbering the
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buffer used by strerror(). */
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# if defined __NetBSD__ || defined __hpux || ((defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__) || defined __CYGWIN__ /* NetBSD, HP-UX, native Win32, Cygwin */
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/* NetBSD: sys_nerr, sys_errlist are declared through _NETBSD_SOURCE
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HP-UX: sys_nerr, sys_errlist are declared explicitly above.
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native Win32: sys_nerr, sys_errlist are declared in <stdlib.h>.
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Cygwin: sys_nerr, sys_errlist are declared in <errno.h>. */
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if (errnum >= 0 && errnum < sys_nerr)
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# if HAVE_CATGETS && (defined __NetBSD__ || defined __hpux)
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# if defined __NetBSD__
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nl_catd catd = catopen ("libc", NL_CAT_LOCALE);
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? catgets (catd, 1, errnum, sys_errlist[errnum])
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: sys_errlist[errnum]);
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nl_catd catd = catopen ("perror", NL_CAT_LOCALE);
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? catgets (catd, 1, 1 + errnum, sys_errlist[errnum])
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: sys_errlist[errnum]);
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const char *errmsg = sys_errlist[errnum];
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if (errmsg == NULL || *errmsg == '\0')
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ret = safe_copy (buf, buflen, errmsg);
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# if HAVE_CATGETS && (defined __NetBSD__ || defined __hpux)
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if (catd != (nl_catd)-1)
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# elif defined __sgi || (defined __sun && !defined _LP64) /* IRIX, Solaris <= 9 32-bit */
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/* For a valid error number, the system's strerror() function returns
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a pointer to a not copied string, not to a buffer. */
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if (errnum >= 0 && errnum < sys_nerr)
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char *errmsg = strerror (errnum);
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if (errmsg == NULL || *errmsg == '\0')
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ret = safe_copy (buf, buflen, errmsg);
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gl_lock_lock (strerror_lock);
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char *errmsg = strerror (errnum);
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/* For invalid error numbers, strerror() on
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- IRIX 6.5 returns NULL,
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- HP-UX 11 returns an empty string. */
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if (errmsg == NULL || *errmsg == '\0')
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ret = safe_copy (buf, buflen, errmsg);
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gl_lock_unlock (strerror_lock);
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if (ret == EINVAL && !*buf)
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snprintf (buf, buflen, "Unknown error %d", errnum);
added
removed
lib/strerror_r.c
