mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-12-23 10:34:07 +00:00
1698036a43
This incorporates: 2016-01-24 openat_proc_name: fix last '/' overwritten on OS/2 kLIBC 2016-01-24 closedir, dirfd, opendir: port to OpenSolaris 5.10 2016-01-15 detect utimes() correctly on OS/2 kLIBC 2016-01-15 openat_proc_name: port to OS/2 kLIBC 2016-01-14 stdint: check _INTPTR_T_DECLARED for intptr_t etc. 2016-01-14 opendir, closedir, dirfd, fdopendir: port to OS/2 kLIBC 2016-01-14 dup, dup2, fcntl: support a directory fd on OS/2 kLIBC 2016-01-14 binary-io: don't put fd in binary mode if a console on EMX 2016-01-14 sig2str: list all signals on FreeBSD >= 7 2016-01-13 acl-permissions: port to USE_ACL==0 platforms 2016-01-12 mktime: rename macro to avoid glibc clash 2016-01-12 Port "$@" to OpenIndiana ksh93 2016-01-12 Port Universal Time settings to strict POSIX * build-aux/gitlog-to-changelog, build-aux/update-copyright: * doc/misc/texinfo.tex, lib/acl-internal.c, lib/acl-internal.h: * lib/binary-io.h, lib/dirent.in.h, lib/dirfd.c, lib/dup2.c: * lib/fcntl.c, lib/fdopendir.c, lib/mktime.c, lib/openat-proc.c: * lib/sig2str.h, lib/stdint.in.h, m4/dirfd.m4, m4/dup2.m4: * m4/fcntl.m4, m4/utimes.m4: Copy from gnulib. * m4/gnulib-comp.m4: Regenerate.
135 lines
4.0 KiB
C
135 lines
4.0 KiB
C
/* Create /proc/self/fd-related names for subfiles of open directories.
|
|
|
|
Copyright (C) 2006, 2009-2016 Free Software Foundation, Inc.
|
|
|
|
This program is free software: you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program 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 General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
|
|
|
/* Written by Paul Eggert. */
|
|
|
|
#include <config.h>
|
|
|
|
#include "openat-priv.h"
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <fcntl.h>
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
|
|
#ifdef __KLIBC__
|
|
# include <InnoTekLIBC/backend.h>
|
|
#endif
|
|
|
|
#include "intprops.h"
|
|
|
|
/* Set BUF to the name of the subfile of the directory identified by
|
|
FD, where the subfile is named FILE. If successful, return BUF if
|
|
the result fits in BUF, dynamically allocated memory otherwise.
|
|
Return NULL (setting errno) on error. */
|
|
char *
|
|
openat_proc_name (char buf[OPENAT_BUFFER_SIZE], int fd, char const *file)
|
|
{
|
|
char *result = buf;
|
|
int dirlen;
|
|
|
|
/* Make sure the caller gets ENOENT when appropriate. */
|
|
if (!*file)
|
|
{
|
|
buf[0] = '\0';
|
|
return buf;
|
|
}
|
|
|
|
#ifndef __KLIBC__
|
|
# define PROC_SELF_FD_FORMAT "/proc/self/fd/%d/"
|
|
{
|
|
enum {
|
|
PROC_SELF_FD_DIR_SIZE_BOUND
|
|
= (sizeof PROC_SELF_FD_FORMAT - (sizeof "%d" - 1)
|
|
+ INT_STRLEN_BOUND (int))
|
|
};
|
|
|
|
static int proc_status = 0;
|
|
if (! proc_status)
|
|
{
|
|
/* Set PROC_STATUS to a positive value if /proc/self/fd is
|
|
reliable, and a negative value otherwise. Solaris 10
|
|
/proc/self/fd mishandles "..", and any file name might expand
|
|
to ".." after symbolic link expansion, so avoid /proc/self/fd
|
|
if it mishandles "..". Solaris 10 has openat, but this
|
|
problem is exhibited on code that built on Solaris 8 and
|
|
running on Solaris 10. */
|
|
|
|
int proc_self_fd = open ("/proc/self/fd",
|
|
O_SEARCH | O_DIRECTORY | O_NOCTTY | O_NONBLOCK);
|
|
if (proc_self_fd < 0)
|
|
proc_status = -1;
|
|
else
|
|
{
|
|
/* Detect whether /proc/self/fd/%i/../fd exists, where %i is the
|
|
number of a file descriptor open on /proc/self/fd. On Linux,
|
|
that name resolves to /proc/self/fd, which was opened above.
|
|
However, on Solaris, it may resolve to /proc/self/fd/fd, which
|
|
cannot exist, since all names in /proc/self/fd are numeric. */
|
|
char dotdot_buf[PROC_SELF_FD_DIR_SIZE_BOUND + sizeof "../fd" - 1];
|
|
sprintf (dotdot_buf, PROC_SELF_FD_FORMAT "../fd", proc_self_fd);
|
|
proc_status = access (dotdot_buf, F_OK) ? -1 : 1;
|
|
close (proc_self_fd);
|
|
}
|
|
}
|
|
|
|
if (proc_status < 0)
|
|
return NULL;
|
|
else
|
|
{
|
|
size_t bufsize = PROC_SELF_FD_DIR_SIZE_BOUND + strlen (file);
|
|
if (OPENAT_BUFFER_SIZE < bufsize)
|
|
{
|
|
result = malloc (bufsize);
|
|
if (! result)
|
|
return NULL;
|
|
}
|
|
|
|
dirlen = sprintf (result, PROC_SELF_FD_FORMAT, fd);
|
|
}
|
|
}
|
|
#else
|
|
/* OS/2 kLIBC provides a function to retrieve a path from a fd. */
|
|
{
|
|
char dir[_MAX_PATH];
|
|
size_t bufsize;
|
|
|
|
if (__libc_Back_ioFHToPath (fd, dir, sizeof dir))
|
|
return NULL;
|
|
|
|
dirlen = strlen (dir);
|
|
bufsize = dirlen + 1 + strlen (file) + 1; /* 1 for '/', 1 for null */
|
|
if (OPENAT_BUFFER_SIZE < bufsize)
|
|
{
|
|
result = malloc (bufsize);
|
|
if (! result)
|
|
return NULL;
|
|
}
|
|
|
|
strcpy (result, dir);
|
|
result[dirlen++] = '/';
|
|
}
|
|
#endif
|
|
|
|
strcpy (result + dirlen, file);
|
|
return result;
|
|
}
|