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File I/O Handling Functions

Modules

 File Open Flags/Routines
 
 File Seek Flags
 
 File Attribute Flags
 
 {_full} max iovec size
 
 File Lock Types
 

Typedefs

typedef apr_uint32_t apr_fileattrs_t
 
typedef int apr_seek_where_t
 
typedef struct apr_file_t apr_file_t
 

Functions

apr_status_t apr_file_open (apr_file_t **newf, const char *fname, apr_int32_t flag, apr_fileperms_t perm, apr_pool_t *pool)
 
apr_status_t apr_file_close (apr_file_t *file)
 
apr_status_t apr_file_remove (const char *path, apr_pool_t *pool)
 
apr_status_t apr_file_rename (const char *from_path, const char *to_path, apr_pool_t *pool)
 
apr_status_t apr_file_link (const char *from_path, const char *to_path)
 
apr_status_t apr_file_copy (const char *from_path, const char *to_path, apr_fileperms_t perms, apr_pool_t *pool)
 
apr_status_t apr_file_append (const char *from_path, const char *to_path, apr_fileperms_t perms, apr_pool_t *pool)
 
apr_status_t apr_file_eof (apr_file_t *fptr)
 
apr_status_t apr_file_open_stderr (apr_file_t **thefile, apr_pool_t *pool)
 
apr_status_t apr_file_open_stdout (apr_file_t **thefile, apr_pool_t *pool)
 
apr_status_t apr_file_open_stdin (apr_file_t **thefile, apr_pool_t *pool)
 
apr_status_t apr_file_open_flags_stderr (apr_file_t **thefile, apr_int32_t flags, apr_pool_t *pool)
 
apr_status_t apr_file_open_flags_stdout (apr_file_t **thefile, apr_int32_t flags, apr_pool_t *pool)
 
apr_status_t apr_file_open_flags_stdin (apr_file_t **thefile, apr_int32_t flags, apr_pool_t *pool)
 
apr_status_t apr_file_read (apr_file_t *thefile, void *buf, apr_size_t *nbytes)
 
apr_status_t apr_file_write (apr_file_t *thefile, const void *buf, apr_size_t *nbytes)
 
apr_status_t apr_file_writev (apr_file_t *thefile, const struct iovec *vec, apr_size_t nvec, apr_size_t *nbytes)
 
apr_status_t apr_file_read_full (apr_file_t *thefile, void *buf, apr_size_t nbytes, apr_size_t *bytes_read)
 
apr_status_t apr_file_write_full (apr_file_t *thefile, const void *buf, apr_size_t nbytes, apr_size_t *bytes_written)
 
apr_status_t apr_file_writev_full (apr_file_t *thefile, const struct iovec *vec, apr_size_t nvec, apr_size_t *nbytes)
 
apr_status_t apr_file_putc (char ch, apr_file_t *thefile)
 
apr_status_t apr_file_getc (char *ch, apr_file_t *thefile)
 
apr_status_t apr_file_ungetc (char ch, apr_file_t *thefile)
 
apr_status_t apr_file_gets (char *str, int len, apr_file_t *thefile)
 
apr_status_t apr_file_puts (const char *str, apr_file_t *thefile)
 
apr_status_t apr_file_flush (apr_file_t *thefile)
 
apr_status_t apr_file_sync (apr_file_t *thefile)
 
apr_status_t apr_file_datasync (apr_file_t *thefile)
 
apr_status_t apr_file_dup (apr_file_t **new_file, apr_file_t *old_file, apr_pool_t *p)
 
apr_status_t apr_file_dup2 (apr_file_t *new_file, apr_file_t *old_file, apr_pool_t *p)
 
apr_status_t apr_file_setaside (apr_file_t **new_file, apr_file_t *old_file, apr_pool_t *p)
 
apr_status_t apr_file_buffer_set (apr_file_t *thefile, char *buffer, apr_size_t bufsize)
 
apr_size_t apr_file_buffer_size_get (apr_file_t *thefile)
 
apr_status_t apr_file_seek (apr_file_t *thefile, apr_seek_where_t where, apr_off_t *offset)
 
apr_status_t apr_file_pipe_create (apr_file_t **in, apr_file_t **out, apr_pool_t *pool)
 
apr_status_t apr_file_pipe_create_ex (apr_file_t **in, apr_file_t **out, apr_int32_t blocking, apr_pool_t *pool)
 
apr_status_t apr_file_namedpipe_create (const char *filename, apr_fileperms_t perm, apr_pool_t *pool)
 
apr_status_t apr_file_pipe_timeout_get (apr_file_t *thepipe, apr_interval_time_t *timeout)
 
apr_status_t apr_file_pipe_timeout_set (apr_file_t *thepipe, apr_interval_time_t timeout)
 
apr_status_t apr_file_lock (apr_file_t *thefile, int type)
 
apr_status_t apr_file_unlock (apr_file_t *thefile)
 
apr_status_t apr_file_name_get (const char **new_path, apr_file_t *thefile)
 
apr_status_t apr_file_data_get (void **data, const char *key, apr_file_t *file)
 
apr_status_t apr_file_data_set (apr_file_t *file, void *data, const char *key, apr_status_t(*cleanup)(void *))
 
int apr_file_printf (apr_file_t *fptr, const char *format,...)
 
apr_status_t apr_file_perms_set (const char *fname, apr_fileperms_t perms)
 
apr_status_t apr_file_attrs_set (const char *fname, apr_fileattrs_t attributes, apr_fileattrs_t attr_mask, apr_pool_t *pool)
 
apr_status_t apr_file_mtime_set (const char *fname, apr_time_t mtime, apr_pool_t *pool)
 
apr_status_t apr_dir_make (const char *path, apr_fileperms_t perm, apr_pool_t *pool)
 
apr_status_t apr_dir_make_recursive (const char *path, apr_fileperms_t perm, apr_pool_t *pool)
 
apr_status_t apr_dir_remove (const char *path, apr_pool_t *pool)
 
apr_status_t apr_file_info_get (apr_finfo_t *finfo, apr_int32_t wanted, apr_file_t *thefile)
 
apr_status_t apr_file_trunc (apr_file_t *fp, apr_off_t offset)
 
apr_int32_t apr_file_flags_get (apr_file_t *f)
 
apr_pool_tapr_file_pool_get (const apr_file_t *thefile)
 
apr_status_t apr_file_inherit_set (apr_file_t *thefile)
 
apr_status_t apr_file_inherit_unset (apr_file_t *thefile)
 
apr_status_t apr_file_mktemp (apr_file_t **fp, char *templ, apr_int32_t flags, apr_pool_t *p)
 
apr_status_t apr_temp_dir_get (const char **temp_dir, apr_pool_t *p)
 

Detailed Description

Typedef Documentation

typedef struct apr_file_t apr_file_t

Structure for referencing files.

typedef apr_uint32_t apr_fileattrs_t

File attributes

typedef int apr_seek_where_t

Type to pass as whence argument to apr_file_seek.

Function Documentation

apr_status_t apr_dir_make ( const char *  path,
apr_fileperms_t  perm,
apr_pool_t pool 
)

Create a new directory on the file system.

Parameters
paththe path for the directory to be created. (use / on all systems)
permPermissions for the new directory.
poolthe pool to use.
apr_status_t apr_dir_make_recursive ( const char *  path,
apr_fileperms_t  perm,
apr_pool_t pool 
)

Creates a new directory on the file system, but behaves like 'mkdir -p'. Creates intermediate directories as required. No error will be reported if PATH already exists.

Parameters
paththe path for the directory to be created. (use / on all systems)
permPermissions for the new directory.
poolthe pool to use.
apr_status_t apr_dir_remove ( const char *  path,
apr_pool_t pool 
)

Remove directory from the file system.

Parameters
paththe path for the directory to be removed. (use / on all systems)
poolthe pool to use.
Remarks
Removing a directory which is in-use (e.g., the current working directory, or during apr_dir_read, or with an open file) is not portable.
apr_status_t apr_file_append ( const char *  from_path,
const char *  to_path,
apr_fileperms_t  perms,
apr_pool_t pool 
)

Append the specified file to another file.

Parameters
from_pathThe full path to the source file (use / on all systems)
to_pathThe full path to the destination file (use / on all systems)
permsAccess permissions for the destination file if it is created. In place of the usual or'd combination of file permissions, the value APR_FPROT_FILE_SOURCE_PERMS may be given, in which case the source file's permissions are copied.
poolThe pool to use.
Remarks
The new file does not need to exist, it will be created if required.
apr_status_t apr_file_attrs_set ( const char *  fname,
apr_fileattrs_t  attributes,
apr_fileattrs_t  attr_mask,
apr_pool_t pool 
)

Set attributes of the specified file.

Parameters
fnameThe full path to the file (using / on all systems)
attributesOr'd combination of
attr_maskMask of valid bits in attributes.
poolthe pool to use.
Remarks
This function should be used in preference to explicit manipulation of the file permissions, because the operations to provide these attributes are platform specific and may involve more than simply setting permission bits.
Warning
Platforms which do not implement this feature will return APR_ENOTIMPL.
apr_status_t apr_file_buffer_set ( apr_file_t thefile,
char *  buffer,
apr_size_t  bufsize 
)

Give the specified apr file handle a new buffer

Parameters
thefileThe file handle that is to be modified
bufferThe buffer
bufsizeThe size of the buffer
Remarks
It is possible to add a buffer to previously unbuffered file handles, the APR_FOPEN_BUFFERED flag will be added to the file handle's flags. Likewise, with buffer=NULL and bufsize=0 arguments it is possible to make a previously buffered file handle unbuffered.
apr_size_t apr_file_buffer_size_get ( apr_file_t thefile)

Get the size of any buffer for the specified apr file handle

Parameters
thefileThe file handle
apr_status_t apr_file_close ( apr_file_t file)

Close the specified file.

Parameters
fileThe file descriptor to close.
apr_status_t apr_file_copy ( const char *  from_path,
const char *  to_path,
apr_fileperms_t  perms,
apr_pool_t pool 
)

Copy the specified file to another file.

Parameters
from_pathThe full path to the original file (using / on all systems)
to_pathThe full path to the new file (using / on all systems)
permsAccess permissions for the new file if it is created. In place of the usual or'd combination of file permissions, the value APR_FPROT_FILE_SOURCE_PERMS may be given, in which case the source file's permissions are copied.
poolThe pool to use.
Remarks
The new file does not need to exist, it will be created if required.
Warning
If the new file already exists, its contents will be overwritten.
apr_status_t apr_file_data_get ( void **  data,
const char *  key,
apr_file_t file 
)

Return the data associated with the current file.

Parameters
dataThe user data associated with the file.
keyThe key to use for retrieving data associated with this file.
fileThe currently open file.
apr_status_t apr_file_data_set ( apr_file_t file,
void *  data,
const char *  key,
apr_status_t(*)(void *)  cleanup 
)

Set the data associated with the current file.

Parameters
fileThe currently open file.
dataThe user data to associate with the file.
keyThe key to use for associating data with the file.
cleanupThe cleanup routine to use when the file is destroyed.
apr_status_t apr_file_datasync ( apr_file_t thefile)

Transfer all file modified data to disk.

Parameters
thefileThe file descriptor to sync
apr_status_t apr_file_dup ( apr_file_t **  new_file,
apr_file_t old_file,
apr_pool_t p 
)

Duplicate the specified file descriptor.

Parameters
new_fileThe structure to duplicate into.
old_fileThe file to duplicate.
pThe pool to use for the new file.
Remarks
*new_file must point to a valid apr_file_t, or point to NULL.
apr_status_t apr_file_dup2 ( apr_file_t new_file,
apr_file_t old_file,
apr_pool_t p 
)

Duplicate the specified file descriptor and close the original

Parameters
new_fileThe old file that is to be closed and reused
old_fileThe file to duplicate
pThe pool to use for the new file
Remarks
new_file MUST point at a valid apr_file_t. It cannot be NULL.
apr_status_t apr_file_eof ( apr_file_t fptr)

Are we at the end of the file

Parameters
fptrThe apr file we are testing.
Remarks
Returns APR_EOF if we are at the end of file, APR_SUCCESS otherwise.
apr_int32_t apr_file_flags_get ( apr_file_t f)

Retrieve the flags that were passed into apr_file_open() when the file was opened.

Returns
apr_int32_t the flags
apr_status_t apr_file_flush ( apr_file_t thefile)

Flush the file's buffer.

Parameters
thefileThe file descriptor to flush
apr_status_t apr_file_getc ( char *  ch,
apr_file_t thefile 
)

Read a character from the specified file.

Parameters
chThe character to read into
thefileThe file descriptor to read from
apr_status_t apr_file_gets ( char *  str,
int  len,
apr_file_t thefile 
)

Read a line from the specified file

Parameters
strThe buffer to store the string in.
lenThe length of the string
thefileThe file descriptor to read from
Remarks
The buffer will be NUL-terminated if any characters are stored. The newline at the end of the line will not be stripped.
apr_status_t apr_file_info_get ( apr_finfo_t finfo,
apr_int32_t  wanted,
apr_file_t thefile 
)

get the specified file's stats.

Parameters
finfoWhere to store the information about the file.
wantedThe desired apr_finfo_t fields, as a bit flag of APR_FINFO_* values
thefileThe file to get information about.
apr_status_t apr_file_inherit_set ( apr_file_t thefile)

Set a file to be inherited by child processes.

apr_status_t apr_file_inherit_unset ( apr_file_t thefile)

Unset a file from being inherited by child processes.

apr_status_t apr_file_link ( const char *  from_path,
const char *  to_path 
)

Create a hard link to the specified file.

Parameters
from_pathThe full path to the original file (using / on all systems)
to_pathThe full path to the new file (using / on all systems)
Remarks
Both files must reside on the same device.
apr_status_t apr_file_lock ( apr_file_t thefile,
int  type 
)

file (un)locking functions. Establish a lock on the specified, open file. The lock may be advisory or mandatory, at the discretion of the platform. The lock applies to the file as a whole, rather than a specific range. Locks are established on a per-thread/process basis; a second lock by the same thread will not block.

Parameters
thefileThe file to lock.
typeThe type of lock to establish on the file.
apr_status_t apr_file_mktemp ( apr_file_t **  fp,
char *  templ,
apr_int32_t  flags,
apr_pool_t p 
)

Open a temporary file

Parameters
fpThe apr file to use as a temporary file.
templThe template to use when creating a temp file.
flagsThe flags to open the file with. If this is zero, the file is opened with APR_FOPEN_CREATE | APR_FOPEN_READ | APR_FOPEN_WRITE | APR_FOPEN_EXCL | APR_FOPEN_DELONCLOSE
pThe pool to allocate the file out of.
Remarks
This function generates a unique temporary file name from template. The last six characters of template must be XXXXXX and these are replaced with a string that makes the filename unique. Since it will be modified, template must not be a string constant, but should be declared as a character array.
apr_status_t apr_file_mtime_set ( const char *  fname,
apr_time_t  mtime,
apr_pool_t pool 
)

Set the mtime of the specified file.

Parameters
fnameThe full path to the file (using / on all systems)
mtimeThe mtime to apply to the file.
poolThe pool to use.
Warning
Platforms which do not implement this feature will return APR_ENOTIMPL.
apr_status_t apr_file_name_get ( const char **  new_path,
apr_file_t thefile 
)

accessor and general file_io functions. return the file name of the current file.

Parameters
new_pathThe path of the file.
thefileThe currently open file.
apr_status_t apr_file_namedpipe_create ( const char *  filename,
apr_fileperms_t  perm,
apr_pool_t pool 
)

Create a named pipe.

Parameters
filenameThe filename of the named pipe
permThe permissions for the newly created pipe.
poolThe pool to operate on.
apr_status_t apr_file_open ( apr_file_t **  newf,
const char *  fname,
apr_int32_t  flag,
apr_fileperms_t  perm,
apr_pool_t pool 
)

Open the specified file.

Parameters
newfThe opened file descriptor.
fnameThe full path to the file (using / on all systems)
flagOr'ed value of:
permAccess permissions for file.
poolThe pool to use.
Remarks
If perm is APR_FPROT_OS_DEFAULT and the file is being created, appropriate default permissions will be used.
By default, the returned file descriptor will not be inherited by child processes created by apr_proc_create(). This can be changed using apr_file_inherit_set().
apr_status_t apr_file_open_flags_stderr ( apr_file_t **  thefile,
apr_int32_t  flags,
apr_pool_t pool 
)

open standard error as an apr file pointer, with flags.

Parameters
thefileThe apr file to use as stderr.
flagsThe flags to open the file with. Only the
poolThe pool to allocate the file out of.
Remarks
See remarks for apr_file_open_stderr().
apr_status_t apr_file_open_flags_stdin ( apr_file_t **  thefile,
apr_int32_t  flags,
apr_pool_t pool 
)

open standard input as an apr file pointer, with flags.

Parameters
thefileThe apr file to use as stdin.
flagsThe flags to open the file with. Only the
poolThe pool to allocate the file out of.
Remarks
See remarks for apr_file_open_stderr().
apr_status_t apr_file_open_flags_stdout ( apr_file_t **  thefile,
apr_int32_t  flags,
apr_pool_t pool 
)

open standard output as an apr file pointer, with flags.

Parameters
thefileThe apr file to use as stdout.
flagsThe flags to open the file with. Only the
poolThe pool to allocate the file out of.
Remarks
See remarks for apr_file_open_stderr().
apr_status_t apr_file_open_stderr ( apr_file_t **  thefile,
apr_pool_t pool 
)

Open standard error as an apr file pointer.

Parameters
thefileThe apr file to use as stderr.
poolThe pool to allocate the file out of.
Remarks
The only reason that the apr_file_open_std* functions exist is that you may not always have a stderr/out/in on Windows. This is generally a problem with newer versions of Windows and services.
The other problem is that the C library functions generally work differently on Windows and Unix. So, by using apr_file_open_std* functions, you can get a handle to an APR struct that works with the APR functions which are supposed to work identically on all platforms.
apr_status_t apr_file_open_stdin ( apr_file_t **  thefile,
apr_pool_t pool 
)

open standard input as an apr file pointer.

Parameters
thefileThe apr file to use as stdin.
poolThe pool to allocate the file out of.
Remarks
See remarks for apr_file_open_stderr().
apr_status_t apr_file_open_stdout ( apr_file_t **  thefile,
apr_pool_t pool 
)

open standard output as an apr file pointer.

Parameters
thefileThe apr file to use as stdout.
poolThe pool to allocate the file out of.
Remarks
See remarks for apr_file_open_stderr().
apr_status_t apr_file_perms_set ( const char *  fname,
apr_fileperms_t  perms 
)

set the specified file's permission bits.

Parameters
fnameThe file (name) to apply the permissions to.
permsThe permission bits to apply to the file.
Warning
Some platforms may not be able to apply all of the available permission bits; APR_INCOMPLETE will be returned if some permissions are specified which could not be set.
Platforms which do not implement this feature will return APR_ENOTIMPL.
apr_status_t apr_file_pipe_create ( apr_file_t **  in,
apr_file_t **  out,
apr_pool_t pool 
)

Create an anonymous pipe.

Parameters
inThe newly created pipe's file for reading.
outThe newly created pipe's file for writing.
poolThe pool to operate on.
Remarks
By default, the returned file descriptors will be inherited by child processes created using apr_proc_create(). This can be changed using apr_file_inherit_unset().
Bug:
Some platforms cannot toggle between blocking and nonblocking, and when passing a pipe as a standard handle to an application which does not expect it, a non-blocking stream will fluxor the client app.
Deprecated:
See Also
apr_file_pipe_create_ex()
apr_status_t apr_file_pipe_create_ex ( apr_file_t **  in,
apr_file_t **  out,
apr_int32_t  blocking,
apr_pool_t pool 
)

Create an anonymous pipe which portably supports async timeout options.

Parameters
inThe newly created pipe's file for reading.
outThe newly created pipe's file for writing.
blockingone of these values defined in apr_thread_proc.h;
poolThe pool to operate on.
Remarks
By default, the returned file descriptors will be inherited by child processes created using apr_proc_create(). This can be changed using apr_file_inherit_unset().
Some platforms cannot toggle between blocking and nonblocking, and when passing a pipe as a standard handle to an application which does not expect it, a non-blocking stream will fluxor the client app. Use this function rather than apr_file_pipe_create() to create pipes where one or both ends require non-blocking semantics.
apr_status_t apr_file_pipe_timeout_get ( apr_file_t thepipe,
apr_interval_time_t timeout 
)

Get the timeout value for a pipe or manipulate the blocking state.

Parameters
thepipeThe pipe we are getting a timeout for.
timeoutThe current timeout value in microseconds.
apr_status_t apr_file_pipe_timeout_set ( apr_file_t thepipe,
apr_interval_time_t  timeout 
)

Set the timeout value for a pipe or manipulate the blocking state.

Parameters
thepipeThe pipe we are setting a timeout on.
timeoutThe timeout value in microseconds. Values < 0 mean wait forever, 0 means do not wait at all.
apr_pool_t* apr_file_pool_get ( const apr_file_t thefile)

Get the pool used by the file.

int apr_file_printf ( apr_file_t fptr,
const char *  format,
  ... 
)

Write a string to a file using a printf format.

Parameters
fptrThe file to write to.
formatThe format string
...The values to substitute in the format string
Returns
The number of bytes written
apr_status_t apr_file_putc ( char  ch,
apr_file_t thefile 
)

Write a character into the specified file.

Parameters
chThe character to write.
thefileThe file descriptor to write to
apr_status_t apr_file_puts ( const char *  str,
apr_file_t thefile 
)

Write the string into the specified file.

Parameters
strThe string to write.
thefileThe file descriptor to write to
apr_status_t apr_file_read ( apr_file_t thefile,
void *  buf,
apr_size_t *  nbytes 
)

Read data from the specified file.

Parameters
thefileThe file descriptor to read from.
bufThe buffer to store the data to.
nbytesOn entry, the number of bytes to read; on exit, the number of bytes read.
Remarks
apr_file_read() will read up to the specified number of bytes, but never more. If there isn't enough data to fill that number of bytes, all of the available data is read. The third argument is modified to reflect the number of bytes read. If a char was put back into the stream via ungetc, it will be the first character returned.
It is not possible for both bytes to be read and an APR_EOF or other error to be returned. APR_EINTR is never returned.
apr_status_t apr_file_read_full ( apr_file_t thefile,
void *  buf,
apr_size_t  nbytes,
apr_size_t *  bytes_read 
)

Read data from the specified file, ensuring that the buffer is filled before returning.

Parameters
thefileThe file descriptor to read from.
bufThe buffer to store the data to.
nbytesThe number of bytes to read.
bytes_readIf non-NULL, this will contain the number of bytes read.
Remarks
apr_file_read_full() will read up to the specified number of bytes, but never more. If there isn't enough data to fill that number of bytes, then the process/thread will block until it is available or EOF is reached. If a char was put back into the stream via ungetc, it will be the first character returned.
It is possible for both bytes to be read and an error to be returned. And if *bytes_read is less than nbytes, an accompanying error is always returned.
APR_EINTR is never returned.
apr_status_t apr_file_remove ( const char *  path,
apr_pool_t pool 
)

Delete the specified file.

Parameters
pathThe full path to the file (using / on all systems)
poolThe pool to use.
Remarks
If the file is open, it won't be removed until all instances are closed.
apr_status_t apr_file_rename ( const char *  from_path,
const char *  to_path,
apr_pool_t pool 
)

Rename the specified file.

Parameters
from_pathThe full path to the original file (using / on all systems)
to_pathThe full path to the new file (using / on all systems)
poolThe pool to use.
Warning
If a file exists at the new location, then it will be overwritten. Moving files or directories across devices may not be possible.
apr_status_t apr_file_seek ( apr_file_t thefile,
apr_seek_where_t  where,
apr_off_t *  offset 
)

Move the read/write file offset to a specified byte within a file.

Parameters
thefileThe file descriptor
whereHow to move the pointer, one of:
  • APR_SET – set the offset to offset
  • APR_CUR – add the offset to the current position
  • APR_END – add the offset to the current file size
offsetThe offset to move the pointer to.
Remarks
The third argument is modified to be the offset the pointer was actually moved to.
apr_status_t apr_file_setaside ( apr_file_t **  new_file,
apr_file_t old_file,
apr_pool_t p 
)

Move the specified file descriptor to a new pool

Parameters
new_filePointer in which to return the new apr_file_t
old_fileThe file to move
pThe pool to which the descriptor is to be moved
Remarks
Unlike apr_file_dup2(), this function doesn't do an OS dup() operation on the underlying descriptor; it just moves the descriptor's apr_file_t wrapper to a new pool.
The new pool need not be an ancestor of old_file's pool.
After calling this function, old_file may not be used
apr_status_t apr_file_sync ( apr_file_t thefile)

Transfer all file modified data and metadata to disk.

Parameters
thefileThe file descriptor to sync
apr_status_t apr_file_trunc ( apr_file_t fp,
apr_off_t  offset 
)

Truncate the file's length to the specified offset

Parameters
fpThe file to truncate
offsetThe offset to truncate to.
Remarks
The read/write file offset is repositioned to offset.
apr_status_t apr_file_ungetc ( char  ch,
apr_file_t thefile 
)

Put a character back onto a specified stream.

Parameters
chThe character to write.
thefileThe file descriptor to write to
apr_status_t apr_file_unlock ( apr_file_t thefile)

Remove any outstanding locks on the file.

Parameters
thefileThe file to unlock.
apr_status_t apr_file_write ( apr_file_t thefile,
const void *  buf,
apr_size_t *  nbytes 
)

Write data to the specified file.

Parameters
thefileThe file descriptor to write to.
bufThe buffer which contains the data.
nbytesOn entry, the number of bytes to write; on exit, the number of bytes written.
Remarks
apr_file_write() will write up to the specified number of bytes, but never more. If the OS cannot write that many bytes, it will write as many as it can. The third argument is modified to reflect the * number of bytes written.
It is possible for both bytes to be written and an error to be returned. APR_EINTR is never returned.
apr_status_t apr_file_write_full ( apr_file_t thefile,
const void *  buf,
apr_size_t  nbytes,
apr_size_t *  bytes_written 
)

Write data to the specified file, ensuring that all of the data is written before returning.

Parameters
thefileThe file descriptor to write to.
bufThe buffer which contains the data.
nbytesThe number of bytes to write.
bytes_writtenIf non-NULL, set to the number of bytes written.
Remarks
apr_file_write_full() will write up to the specified number of bytes, but never more. If the OS cannot write that many bytes, the process/thread will block until they can be written. Exceptional error such as "out of space" or "pipe closed" will terminate with an error.
It is possible for both bytes to be written and an error to be returned. And if *bytes_written is less than nbytes, an accompanying error is always returned.
APR_EINTR is never returned.
apr_status_t apr_file_writev ( apr_file_t thefile,
const struct iovec *  vec,
apr_size_t  nvec,
apr_size_t *  nbytes 
)

Write data from iovec array to the specified file.

Parameters
thefileThe file descriptor to write to.
vecThe array from which to get the data to write to the file.
nvecThe number of elements in the struct iovec array. This must be smaller than APR_MAX_IOVEC_SIZE. If it isn't, the function will fail with APR_EINVAL.
nbytesThe number of bytes written.
Remarks
It is possible for both bytes to be written and an error to be returned. APR_EINTR is never returned.
apr_file_writev() is available even if the underlying operating system doesn't provide writev().
apr_status_t apr_file_writev_full ( apr_file_t thefile,
const struct iovec *  vec,
apr_size_t  nvec,
apr_size_t *  nbytes 
)

Write data from iovec array to the specified file, ensuring that all of the data is written before returning.

Parameters
thefileThe file descriptor to write to.
vecThe array from which to get the data to write to the file.
nvecThe number of elements in the struct iovec array. This must be smaller than APR_MAX_IOVEC_SIZE. If it isn't, the function will fail with APR_EINVAL.
nbytesThe number of bytes written.
Remarks
apr_file_writev_full() is available even if the underlying operating system doesn't provide writev().
apr_status_t apr_temp_dir_get ( const char **  temp_dir,
apr_pool_t p 
)

Find an existing directory suitable as a temporary storage location.

Parameters
temp_dirThe temp directory.
pThe pool to use for any necessary allocations.
Remarks
This function uses an algorithm to search for a directory that an an application can use for temporary storage.