glibc/sysdeps/posix/pathconf.c

236 lines
4.7 KiB
C

/* Copyright (C) 1991-2014 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <stddef.h>
#include <unistd.h>
#include <limits.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/statfs.h>
#include <sys/statvfs.h>
/* Get file-specific information about PATH. */
long int
__pathconf (const char *path, int name)
{
if (path[0] == '\0')
{
__set_errno (ENOENT);
return -1;
}
switch (name)
{
default:
__set_errno (EINVAL);
return -1;
case _PC_LINK_MAX:
#ifdef LINK_MAX
return LINK_MAX;
#else
return -1;
#endif
case _PC_MAX_CANON:
#ifdef MAX_CANON
return MAX_CANON;
#else
return -1;
#endif
case _PC_MAX_INPUT:
#ifdef MAX_INPUT
return MAX_INPUT;
#else
return -1;
#endif
case _PC_NAME_MAX:
#ifdef NAME_MAX
{
struct statfs buf;
int save_errno = errno;
if (__statfs (path, &buf) < 0)
{
if (errno == ENOSYS)
{
errno = save_errno;
return NAME_MAX;
}
return -1;
}
else
{
#ifdef _STATFS_F_NAMELEN
return buf.f_namelen;
#else
# ifdef _STATFS_F_NAME_MAX
return buf.f_name_max;
# else
return NAME_MAX;
# endif
#endif
}
}
#else
return -1;
#endif
case _PC_PATH_MAX:
#ifdef PATH_MAX
return PATH_MAX;
#else
return -1;
#endif
case _PC_PIPE_BUF:
#ifdef PIPE_BUF
return PIPE_BUF;
#else
return -1;
#endif
case _PC_CHOWN_RESTRICTED:
#ifdef _POSIX_CHOWN_RESTRICTED
return _POSIX_CHOWN_RESTRICTED;
#else
return -1;
#endif
case _PC_NO_TRUNC:
#ifdef _POSIX_NO_TRUNC
return _POSIX_NO_TRUNC;
#else
return -1;
#endif
case _PC_VDISABLE:
#ifdef _POSIX_VDISABLE
return _POSIX_VDISABLE;
#else
return -1;
#endif
case _PC_SYNC_IO:
#ifdef _POSIX_SYNC_IO
return _POSIX_SYNC_IO;
#else
return -1;
#endif
case _PC_ASYNC_IO:
#ifdef _POSIX_ASYNC_IO
{
/* AIO is only allowed on regular files and block devices. */
struct stat64 st;
if (__xstat64 (_STAT_VER, path, &st) < 0
|| (! S_ISREG (st.st_mode) && ! S_ISBLK (st.st_mode)))
return -1;
else
return 1;
}
#else
return -1;
#endif
case _PC_PRIO_IO:
#ifdef _POSIX_PRIO_IO
return _POSIX_PRIO_IO;
#else
return -1;
#endif
case _PC_SOCK_MAXBUF:
#ifdef SOCK_MAXBUF
return SOCK_MAXBUF;
#else
return -1;
#endif
case _PC_FILESIZEBITS:
#ifdef FILESIZEBITS
return FILESIZEBITS;
#else
/* We let platforms with larger file sizes overwrite this value. */
return 32;
#endif
case _PC_REC_INCR_XFER_SIZE:
/* XXX It is not entirely clear what the limit is supposed to do.
What is incremented? */
return -1;
case _PC_REC_MAX_XFER_SIZE:
/* XXX It is not entirely clear what the limit is supposed to do.
In general there is no top limit of the number of bytes which
case be transported at once. */
return -1;
case _PC_REC_MIN_XFER_SIZE:
{
/* XXX It is not entirely clear what the limit is supposed to do.
I assume this is the block size of the filesystem. */
struct statvfs64 sv;
if (__statvfs64 (path, &sv) < 0)
return -1;
return sv.f_bsize;
}
case _PC_REC_XFER_ALIGN:
{
/* XXX It is not entirely clear what the limit is supposed to do.
I assume that the number should reflect the minimal block
alignment. */
struct statvfs64 sv;
if (__statvfs64 (path, &sv) < 0)
return -1;
return sv.f_frsize;
}
case _PC_ALLOC_SIZE_MIN:
{
/* XXX It is not entirely clear what the limit is supposed to do.
I assume that the number should reflect the minimal block
alignment. */
struct statvfs64 sv;
if (__statvfs64 (path, &sv) < 0)
return -1;
return sv.f_frsize;
}
case _PC_SYMLINK_MAX:
/* In general there are no limits. If a system has one it should
overwrite this case. */
return -1;
case _PC_2_SYMLINKS:
/* Unix systems generally have symlinks. */
return 1;
}
}
#undef __pathconf
weak_alias (__pathconf, pathconf)