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Colin Walters authored
rpm-ostree at least uses `dirname()` and relied on the `#include <libgen.h>` that we had previously.
Colin Walters authoredrpm-ostree at least uses `dirname()` and relied on the `#include <libgen.h>` that we had previously.
glnx-fdio.h 11.04 KiB
/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
*
* Copyright (C) 2014,2015 Colin Walters <walters@verbum.org>.
*
* This 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 of the License, or (at your option) any later version.
*
* This 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 this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#pragma once
#include <glnx-backport-autocleanups.h>
#include <gio/gfiledescriptorbased.h>
#include <limits.h>
#include <dirent.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <stdio.h>
#include <sys/xattr.h>
// For dirname(), and previously basename()
#include <libgen.h>
#include <glnx-macros.h>
#include <glnx-errors.h>
G_BEGIN_DECLS
/* Irritatingly, g_basename() which is what we want
* is deprecated.
*/
static inline
const char *glnx_basename (const char *path)
{
gchar *base = strrchr (path, G_DIR_SEPARATOR);
if (base)
return base + 1;
return path;
}
/* Utilities for standard FILE* */
static inline void
glnx_stdio_file_cleanup (void *filep)
{
FILE *f = filep;
if (f)
fclose (f);
}
G_DEFINE_AUTOPTR_CLEANUP_FUNC(FILE, glnx_stdio_file_cleanup)
/**
* glnx_stdio_file_flush:
* Call fflush() and check ferror().
*/
gboolean
glnx_stdio_file_flush (FILE *f, GError **error);
typedef struct {
gboolean initialized;
gboolean anonymous;
int src_dfd;
int fd;
char *path;
} GLnxTmpfile;
void glnx_tmpfile_clear (GLnxTmpfile *tmpf);
G_DEFINE_AUTO_CLEANUP_CLEAR_FUNC(GLnxTmpfile, glnx_tmpfile_clear)
gboolean
glnx_open_anonymous_tmpfile (int flags,
GLnxTmpfile *out_tmpf,
GError **error);
gboolean
glnx_open_tmpfile_linkable_at (int dfd,
const char *subpath,
int flags,
GLnxTmpfile *out_tmpf,
GError **error);
typedef enum {
GLNX_LINK_TMPFILE_REPLACE,
GLNX_LINK_TMPFILE_NOREPLACE,
GLNX_LINK_TMPFILE_NOREPLACE_IGNORE_EXIST
} GLnxLinkTmpfileReplaceMode;
gboolean
glnx_link_tmpfile_at (GLnxTmpfile *tmpf,
GLnxLinkTmpfileReplaceMode flags,
int target_dfd,
const char *target,
GError **error);
gboolean
glnx_openat_rdonly (int dfd,
const char *path,
gboolean follow,
int *out_fd,
GError **error);
GBytes *
glnx_fd_readall_bytes (int fd,
GCancellable *cancellable,
GError **error);
char *
glnx_fd_readall_utf8 (int fd,
gsize *out_len,
GCancellable *cancellable,
GError **error);
char *
glnx_file_get_contents_utf8_at (int dfd,
const char *subpath,
gsize *out_len,
GCancellable *cancellable,
GError **error);
/**
* GLnxFileReplaceFlags:
* @GLNX_FILE_REPLACE_DATASYNC_NEW: Call fdatasync() even if the file did not exist
* @GLNX_FILE_REPLACE_NODATASYNC: Never call fdatasync()
*
* Flags controlling file replacement.
*/
typedef enum {
GLNX_FILE_REPLACE_DATASYNC_NEW = (1 << 0),
GLNX_FILE_REPLACE_NODATASYNC = (1 << 1),
} GLnxFileReplaceFlags;
gboolean
glnx_file_replace_contents_at (int dfd,
const char *subpath,
const guint8 *buf,
gsize len,
GLnxFileReplaceFlags flags,
GCancellable *cancellable,
GError **error);
gboolean
glnx_file_replace_contents_with_perms_at (int dfd,
const char *subpath,
const guint8 *buf,
gsize len,
mode_t mode,
uid_t uid,
gid_t gid,
GLnxFileReplaceFlags flags,
GCancellable *cancellable,
GError **error);
char *
glnx_readlinkat_malloc (int dfd,
const char *subpath,
GCancellable *cancellable,
GError **error);
int
glnx_loop_write (int fd, const void *buf, size_t nbytes);
int
glnx_regfile_copy_bytes (int fdf, int fdt, off_t max_bytes);
typedef enum {
GLNX_FILE_COPY_OVERWRITE = (1 << 0),
GLNX_FILE_COPY_NOXATTRS = (1 << 1),
GLNX_FILE_COPY_DATASYNC = (1 << 2)
} GLnxFileCopyFlags;
gboolean
glnx_file_copy_at (int src_dfd,
const char *src_subpath,
struct stat *src_stbuf,
int dest_dfd,
const char *dest_subpath,
GLnxFileCopyFlags copyflags,
GCancellable *cancellable,
GError **error);
int glnx_renameat2_noreplace (int olddirfd, const char *oldpath,
int newdirfd, const char *newpath);
int glnx_renameat2_exchange (int olddirfd, const char *oldpath,
int newdirfd, const char *newpath);
/**
* glnx_try_fallocate:
* @fd: File descriptor
* @size: Size
* @error: Error
*
* Wrapper for Linux fallocate(). Explicitly ignores a @size of zero.
* Also, will silently do nothing if the underlying filesystem doesn't
* support it. Use this instead of posix_fallocate(), since the glibc fallback
* is bad: https://sourceware.org/bugzilla/show_bug.cgi?id=18515
*/
static inline gboolean
glnx_try_fallocate (int fd,
off_t offset,
off_t size,
GError **error)
{
/* This is just nicer than throwing an error */
if (size == 0)
return TRUE;
if (fallocate (fd, 0, offset, size) < 0)
{
if (G_IN_SET(errno, ENOSYS, EOPNOTSUPP))
; /* Ignore */
else
return glnx_throw_errno_prefix (error, "fallocate");
}
return TRUE;
}
/**
* glnx_fstat:
* @fd: FD to stat
* @buf: (out caller-allocates): Return location for stat details
* @error: Return location for a #GError, or %NULL
*
* Wrapper around fstat() which adds #GError support and ensures that it retries
* on %EINTR.
*
* Returns: %TRUE on success, %FALSE otherwise
* Since: UNRELEASED
*/
static inline gboolean
glnx_fstat (int fd,
struct stat *buf,
GError **error)
{
if (TEMP_FAILURE_RETRY (fstat (fd, buf)) != 0)
return glnx_throw_errno_prefix (error, "fstat");
return TRUE;
}
/**
* glnx_fchmod:
* @fd: FD
* @mode: Mode
* @error: Return location for a #GError, or %NULL
*
* Wrapper around fchmod() which adds #GError support and ensures that it
* retries on %EINTR.
*
* Returns: %TRUE on success, %FALSE otherwise
* Since: UNRELEASED
*/
static inline gboolean
glnx_fchmod (int fd,
mode_t mode,
GError **error)
{
if (TEMP_FAILURE_RETRY (fchmod (fd, mode)) != 0)
return glnx_throw_errno_prefix (error, "fchmod");
return TRUE;
}
/**
* glnx_fstatat:
* @dfd: Directory FD to stat beneath
* @path: Path to stat beneath @dfd
* @buf: (out caller-allocates): Return location for stat details
* @flags: Flags to pass to fstatat()
* @error: Return location for a #GError, or %NULL
*
* Wrapper around fstatat() which adds #GError support and ensures that it
* retries on %EINTR.
*
* Returns: %TRUE on success, %FALSE otherwise
* Since: UNRELEASED
*/
static inline gboolean
glnx_fstatat (int dfd,
const gchar *path,
struct stat *buf,
int flags,
GError **error)
{
if (TEMP_FAILURE_RETRY (fstatat (dfd, path, buf, flags)) != 0)
return glnx_throw_errno_prefix (error, "fstatat(%s)", path);
return TRUE;
}
/**
* glnx_fstatat_allow_noent:
* @dfd: Directory FD to stat beneath
* @path: Path to stat beneath @dfd
* @buf: (out caller-allocates) (allow-none): Return location for stat details
* @flags: Flags to pass to fstatat()
* @error: Return location for a #GError, or %NULL
*
* Like glnx_fstatat(), but handles `ENOENT` in a non-error way. Instead,
* on success `errno` will be zero, otherwise it will be preserved. Hence
* you can test `if (errno == 0)` to conditionalize on the file existing,
* or `if (errno == ENOENT)` for non-existence.
*
* Returns: %TRUE on success, %FALSE otherwise (errno is preserved)
* Since: UNRELEASED
*/
static inline gboolean
glnx_fstatat_allow_noent (int dfd,
const char *path,
struct stat *out_buf,
int flags,
GError **error)
{
G_GNUC_UNUSED struct stat unused_stbuf;
if (TEMP_FAILURE_RETRY (fstatat (dfd, path, out_buf ? out_buf : &unused_stbuf, flags)) != 0)
{
if (errno != ENOENT)
return glnx_throw_errno_prefix (error, "fstatat(%s)", path);
/* Note we preserve errno as ENOENT */
}
else
errno = 0;
return TRUE;
}
/**
* glnx_renameat:
*
* Wrapper around renameat() which adds #GError support and ensures that it
* retries on %EINTR.
*/
static inline gboolean
glnx_renameat (int src_dfd,
const gchar *src_path,
int dest_dfd,
const gchar *dest_path,
GError **error)
{
if (TEMP_FAILURE_RETRY (renameat (src_dfd, src_path, dest_dfd, dest_path)) != 0)
return glnx_throw_errno_prefix (error, "renameat(%s, %s)", src_path, dest_path);
return TRUE;
}
/**
* glnx_unlinkat:
*
* Wrapper around unlinkat() which adds #GError support and ensures that it
* retries on %EINTR.
*/
static inline gboolean
glnx_unlinkat (int dfd,
const gchar *path,
int flags,
GError **error)
{
if (TEMP_FAILURE_RETRY (unlinkat (dfd, path, flags)) != 0)
return glnx_throw_errno_prefix (error, "unlinkat(%s)", path);
return TRUE;
}
G_END_DECLS