apr_file_io.h

Apache V2.0.15 Alpha For Linuxhttpd-2_0_15-alpha.tar.Z

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#ifndef APR_FILE_IO_H
#define APR_FILE_IO_H

#include "apr.h"
#include "apr_pools.h"
#include "apr_time.h"
#include "apr_errno.h"
#include "apr_file_info.h"

#define APR_WANT_STDIO          /* for SEEK_* */
#define APR_WANT_IOVEC
#include "apr_want.h"

#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */

/**
 * @package APR File handling
 */

/* Flags for apr_file_open */
#define APR_READ       1           /* Open the file for reading */
#define APR_WRITE      2           /* Open the file for writing */
#define APR_CREATE     4           /* Create the file if not there */
#define APR_APPEND     8           /* Append to the end of the file */
#define APR_TRUNCATE   16          /* Open the file and truncate to 0 length */
#define APR_BINARY     32          /* Open the file in binary mode */
#define APR_EXCL       64          /* Open should fail if APR_CREATE and file
				    exists. */
#define APR_BUFFERED   128         /* Open the file for buffered I/O */
#define APR_DELONCLOSE 256         /* Delete the file after close */
#define APR_XTHREAD    512         /* Platform dependent tag to open the file 
                                      for use across multiple threads */

/* flags for apr_file_seek */
#define APR_SET SEEK_SET
#define APR_CUR SEEK_CUR
#define APR_END SEEK_END

/* should be same as whence type in lseek, POSIX defines this as int */
typedef apr_int32_t       apr_seek_where_t;

/**
 * Structure for referencing files.
 * @defvar apr_file_t
 */
typedef struct apr_file_t         apr_file_t;

/* File lock types/flags */
#define APR_FLOCK_SHARED        1       /* Shared lock. More than one process
                                           or thread can hold a shared lock
                                           at any given time. Essentially,
                                           this is a "read lock", preventing
                                           writers from establishing an
                                           exclusive lock. */
#define APR_FLOCK_EXCLUSIVE     2       /* Exclusive lock. Only one process
                                           may hold an exclusive lock at any
                                           given time. This is analogous to
                                           a "write lock". */

#define APR_FLOCK_TYPEMASK      0x000F  /* mask to extract lock type */
#define APR_FLOCK_NONBLOCK      0x0010  /* do not block while acquiring the
                                           file lock */

/**
 * Open the specified file.
 * @param new_file The opened file descriptor.
 * @param fname The full path to the file (using / on all systems)
 * @param flag Or'ed value of:
 * <PRE>
 *           APR_READ             open for reading
 *           APR_WRITE            open for writing
 *           APR_CREATE           create the file if not there
 *           APR_APPEND           file ptr is set to end prior to all writes
 *           APR_TRUNCATE         set length to zero if file exists
 *           APR_BINARY           not a text file (This flag is ignored on 
 *                                UNIX because it has no meaning)
 *           APR_BUFFERED         buffer the data.  Default is non-buffered
 *           APR_EXCL             return error if APR_CREATE and file exists
 *           APR_DELONCLOSE       delete the file after closing.
 * </PRE>
 * @param perm Access permissions for file.
 * @param cont The pool to use.
 * @deffunc apr_status_t apr_file_open(apr_file_t **new_file, const char *fname, apr_int32_t flag, apr_fileperms_t perm, apr_pool_t *cont)
 * @tip If perm is APR_OS_DEFAULT and the file is being created, appropriate 
 *      default permissions will be used.  *arg1 must point to a valid file_t, 
 *      or NULL (in which case it will be allocated)
 */
APR_DECLARE(apr_status_t) apr_file_open(apr_file_t **new_file, const char *fname,
                                   apr_int32_t flag, apr_fileperms_t perm,
                                   apr_pool_t *cont);

/**
 * Close the specified file.
 * @param file The file descriptor to close.
 * @deffunc apr_status_t apr_file_close(apr_file_t *file)
 */
APR_DECLARE(apr_status_t) apr_file_close(apr_file_t *file);

/**
 * delete the specified file.
 * @param path The full path to the file (using / on all systems)
 * @param cont The pool to use.
 * @deffunc apr_status_t apr_file_remove(const char *path, apr_pool_t *cont)
 * @tip If the file is open, it won't be removed until all instances are closed.
 */
APR_DECLARE(apr_status_t) apr_file_remove(const char *path, apr_pool_t *cont);

/**
 * rename the specified file.
 * @param from_path The full path to the original file (using / on all systems)
 * @param to_path The full path to the new file (using / on all systems)
 * @param pool The pool to use.
 * @tip If a file exists at the new location, then it will be overwritten.  
 *      Moving files or directories across devices may not be possible.
 * @deffunc apr_status_t apr_file_rename(const char *from_path, const char *to_path, apr_pool_t *pool)
 */
APR_DECLARE(apr_status_t) apr_file_rename(const char *from_path, 
                                          const char *to_path,
                                          apr_pool_t *pool);

/**
 * Are we at the end of the file
 * @param fptr The apr file we are testing.
 * @tip Returns APR_EOF if we are at the end of file, APR_SUCCESS otherwise.
 * @deffunc apr_status_t apr_file_eof(apr_file_t *fptr)
 */
APR_DECLARE(apr_status_t) apr_file_eof(apr_file_t *fptr);

/**
 * Is there an error on the stream?
 * @param fptr The apr file we are testing.
 * @tip Returns -1 if the error indicator is set, APR_SUCCESS otherwise.
 * @deffunc apr_status_t apr_file_error(apr_file_t *fptr)
 */
APR_DECLARE(apr_status_t) apr_file_error(apr_file_t *fptr);

/**
 * open standard error as an apr file pointer.
 * @param thefile The apr file to use as stderr.
 * @param cont The pool to allocate the file out of.
 * @deffunc apr_status_t apr_file_open_stderr(apr_file_t **thefile, apr_pool_t *cont)
 */
APR_DECLARE(apr_status_t) apr_file_open_stderr(apr_file_t **thefile,
                                          apr_pool_t *cont);

/**
 * open standard output as an apr file pointer.
 * @param thefile The apr file to use as stdout.
 * @param cont The pool to allocate the file out of.
 * @deffunc apr_status_t apr_file_open_stdout(apr_file_t **thefile, apr_pool_t *cont)
 */
APR_DECLARE(apr_status_t) apr_file_open_stdout(apr_file_t **thefile,
                                          apr_pool_t *cont);

/**
 * Read data from the specified file.
 * @param thefile The file descriptor to read from.
 * @param buf The buffer to store the data to.
 * @param nbytes On entry, the number of bytes to read; on exit, the number of bytes read.
 * @tip 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 possible for both bytes to be read and an APR_EOF or other 
 *      error to be returned.
 *
 *      APR_EINTR is never returned.
 * @deffunc apr_status_t apr_file_read(apr_file_t *thefile, void *buf, apr_size_t *nbytes)
 */
APR_DECLARE(apr_status_t) apr_file_read(apr_file_t *thefile, void *buf,
                                   apr_size_t *nbytes);

/**
 * Write data to the specified file.
 * @param thefile The file descriptor to write to.
 * @param buf The buffer which contains the data.
 * @param nbytes On entry, the number of bytes to write; on exit, the number 
 *               of bytes written.
 * @tip 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.
 * @deffunc apr_status_t apr_file_write(apr_file_t *thefile, const void *buf, apr_size_t *nbytes)
 */
APR_DECLARE(apr_status_t) apr_file_write(apr_file_t *thefile, const void *buf,
                                    apr_size_t *nbytes);

/**
 * Write data from iovec array to the specified file.
 * @param thefile The file descriptor to write to.
 * @param vec The array from which to get the data to write to the file.
 * @param nvec The 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.
 * @param nbytes The number of bytes written.
 * @tip 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().
 * @deffunc apr_status_t apr_file_writev(apr_file_t *thefile, const struct iovec *vec, apr_size_t nvec, apr_size_t *nbytes)
 */
APR_DECLARE(apr_status_t) apr_file_writev(apr_file_t *thefile,
                                     const struct iovec *vec,
                                     apr_size_t nvec, apr_size_t *nbytes);

/**
 * Read data from the specified file, ensuring that the buffer is filled
 * before returning.
 * @param thefile The file descriptor to read from.
 * @param buf The buffer to store the data to.
 * @param nbytes The number of bytes to read.
 * @param bytes_read If non-NULL, this will contain the number of bytes read.