path: root/include/apr_file_io.h

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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 */
#define APR_SHARELOCK  1024        /* Platform dependent support for higher
                                      level locked read/write access to support
                                      writes across process/machines */

/* 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);

/**
 * 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);

/**
 * open standard input as an apr file pointer.
 * @param thefile The apr file to use as stdin.
 * @param cont The pool to allocate the file out of.
 * @deffunc apr_status_t apr_file_open_stdin(apr_file_t **thefile, apr_pool_t *cont)
 */
APR_DECLARE(apr_status_t) apr_file_open_stdin(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 not 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.
 * @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, 
 *      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 not 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_full(apr_file_t *thefile, void *buf, apr_size_t nbytes, apr_size_t *bytes_read)
 */
APR_DECLARE(apr_status_t) apr_file_read_full(apr_file_t *thefile, void *buf,
                                        apr_size_t nbytes,
                                        apr_size_t *bytes_read);

/**
 * Write data to the specified file, ensuring that all of the data is
 * written before returning.
 * @param thefile The file descriptor to write to.
 * @param buf The buffer which contains the data.
 * @param nbytes The number of bytes to write.
 * @param bytes_written If non-NULL, this will contain 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, 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.
 *
 *      APR_EINTR is never returned.
 * @deffunc apr_status_t apr_file_write_full(apr_file_t *thefile, const void *buf, apr_size_t nbytes, apr_size_t *bytes_written)
 */
APR_DECLARE(apr_status_t) apr_file_write_full(apr_file_t *thefile, const void *buf,
                                         apr_size_t nbytes, 
                                         apr_size_t *bytes_written);

/**
 * put a character into the specified file.
 * @param ch The character to write.
 * @param thefile The file descriptor to write to
 * @deffunc apr_status_t apr_file_putc(char ch, apr_file_t *thefile)
 */
APR_DECLARE(apr_status_t) apr_file_putc(char ch, apr_file_t *thefile);

/**
 * get a character from the specified file.
 * @param ch The character to write.
 * @param thefile The file descriptor to write to
 * @deffunc apr_status_t apr_file_getc(char *ch, apr_file_t *thefile)
 */
APR_DECLARE(apr_status_t) apr_file_getc(char *ch, apr_file_t *thefile);

/**
 * put a character back onto a specified stream.
 * @param ch The character to write.
 * @param thefile The file descriptor to write to
 * @deffunc apr_status_t apr_file_ungetc(char ch, apr_file_t *thefile)
 */
APR_DECLARE(apr_status_t) apr_file_ungetc(char ch, apr_file_t *thefile);

/**
 * Get a string from a specified file.
 * @param str The buffer to store the string in. 
 * @param len The length of the string
 * @param thefile The file descriptor to read from
 * @deffunc apr_status_t apr_file_gets(char *str, int len, apr_file_t *thefile)
 */
APR_DECLARE(apr_status_t) apr_file_gets(char *str, int len, apr_file_t *thefile);

/**
 * Put the string into a specified file.
 * @param str The string to write. 
 * @param thefile The file descriptor to write to
 * @deffunc apr_status_t apr_file_puts(const char *str, apr_file_t *thefile)
 */
APR_DECLARE(apr_status_t) apr_file_puts(const char *str, apr_file_t *thefile);

/**
 * Flush the file's buffer.
 * @param thefile The file descriptor to flush
 * @deffunc apr_status_t apr_file_flush(apr_file_t *thefile)
 */
APR_DECLARE(apr_status_t) apr_file_flush(apr_file_t *thefile);

/**
 * duplicate the specified file descriptor.
 * @param new_file The structure to duplicate into. 
 * @param old_file The file to duplicate.
 * @param p The pool to use for the new file.
 * @tip *arg1 must point to a valid apr_file_t, or point to NULL
 * @deffunc apr_status_t apr_file_dup(apr_file_t **new_file, apr_file_t *old_file, apr_pool_t *p)
 */         
APR_DECLARE(apr_status_t) apr_file_dup(apr_file_t **new_file,
                                      apr_file_t *old_file,
                                      apr_pool_t *p);

/**
 * Move the read/write file offset to a specified byte within a file.
 * @param thefile The file descriptor
 * @param where How to move the pointer, one of:
 * <PRE>
 *            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 
 * </PRE>
 * @param offset The offset to move the pointer to.
 * @tip The third argument is modified to be the offset the pointer
          was actually moved to.
 * @deffunc apr_status_t apr_file_seek(apr_file_t *thefile, apr_seek_where_t where, apr_off_t *offset)
 */
APR_DECLARE(apr_status_t) apr_file_seek(apr_file_t *thefile, 
                                   apr_seek_where_t where,
                                   apr_off_t *offset);

/**
 * Create an anonymous pipe.
 * @param in The file descriptor to use as input to the pipe.
 * @param out The file descriptor to use as output from the pipe.
 * @param cont The pool to operate on.
 * @deffunc apr_status_t apr_file_pipe_create(apr_file_t **in, apr_file_t **out, apr_pool_t *cont)
 */
APR_DECLARE(apr_status_t) apr_file_pipe_create(apr_file_t **in, apr_file_t **out,
                                          apr_pool_t *cont);

/**
 * Create a named pipe.
 * @param filename The filename of the named pipe
 * @param perm The permissions for the newly created pipe.
 * @param cont The pool to operate on.
 * @deffunc apr_status_t apr_file_namedpipe_create(const char *filename, apr_fileperms_t perm, apr_pool_t *cont)
 */
APR_DECLARE(apr_status_t) apr_file_namedpipe_create(const char *filename, 
                                               apr_fileperms_t perm, 
                                               apr_pool_t *cont);

/**
 * Get the timeout value for a pipe or manipulate the blocking state.
 * @param thepipe The pipe we are getting a timeout for.
 * @param timeout The current timeout value in microseconds. 
 * @deffunc apr_status_t apr_file_pipe_timeout_get(apr_file_t *thepipe, apr_interval_time_t *timeout)
 */
APR_DECLARE(apr_status_t) apr_file_pipe_timeout_get(apr_file_t *thepipe, 
                                               apr_interval_time_t *timeout);

/**
 * Set the timeout value for a pipe or manipulate the blocking state.
 * @param thepipe The pipe we are setting a timeout on.
 * @param timeout The timeout value in microseconds.  Values < 0 mean wait 
 *        forever, 0 means do not wait at all.
 * @deffunc apr_status_t apr_file_pipe_timeout_set(apr_file_t *thepipe, apr_interval_time_t timeout)
 */
APR_DECLARE(apr_status_t) apr_file_pipe_timeout_set(apr_file_t *thepipe, 
                                               apr_interval_time_t timeout);

/** 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.
 * @param thefile The file to lock.
 * @param type The type of lock to establish on the file.
 * @deffunc apr_status_t apr_file_lock(apr_file_t *thefile, int type)
 */
APR_DECLARE(apr_status_t) apr_file_lock(apr_file_t *thefile, int type);

/**
 * Remove any outstanding locks on the file.
 * @param thefile The file to unlock.
 * @deffunc apr_status_t apr_file_unlock(apr_file_t *thefile)
 */
APR_DECLARE(apr_status_t) apr_file_unlock(apr_file_t *thefile);

/**accessor and general file_io functions. */

/**
 * return the file name of the current file.
 * @param new_path The path of the file.  
 * @param thefile The currently open file.
 * @deffunc apr_status_t apr_file_name_get(const char **new_path, apr_file_t *thefile)
 */                     
APR_DECLARE(apr_status_t) apr_file_name_get(const char **new_path, 
                                           apr_file_t *thefile);

/**
 * Return the data associated with the current file.
 * @param data The user data associated with the file.  
 * @param key The key to use for retreiving data associated with this file.
 * @param file The currently open file.
 * @deffunc apr_status_t apr_file_data_get(void **data, const char *key, apr_file_t *file)
 */                     
APR_DECLARE(apr_status_t) apr_file_data_get(void **data, const char *key, 
                                           apr_file_t *file);

/**
 * Set the data associated with the current file.
 * @param file The currently open file.
 * @param data The user data to associate with the file.  
 * @param key The key to use for assocaiteing data with the file.
 * @param cleanup The cleanup routine to use when the file is destroyed.
 * @deffunc apr_status_t apr_file_data_set(apr_file_t *file, void *data, const char *key, apr_status_t (*cleanup)(void *))
 */                     
APR_DECLARE(apr_status_t) apr_file_data_set(apr_file_t *file, void *data,
                                           const char *key,
                                           apr_status_t (*cleanup)(void *));

/**
 * Write a string to a file using a printf format.
 * @param fptr The file to write to.
 * @param format The format string
 * @param ... The values to substitute in the format string
 * @return The number of bytes written
 * @deffunc int apr_file_printf(apr_file_t *fptr, const char *format, ...)
 */ 
APR_DECLARE_NONSTD(int) apr_file_printf(apr_file_t *fptr, const char *format, ...)
        __attribute__((format(printf,2,3)));

/**
 * set the specified file's permission bits.
 * @param fname The file (name) to apply the permissions to.
 * @param perms The permission bits to apply to the file.
 * @tip 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.
 * @deffunc apr_status_t apr_file_perms_set(const char *fname, apr_fileperms_t perms)
 */
APR_DECLARE(apr_status_t) apr_file_perms_set(const char *fname,
                                           apr_fileperms_t perms);

/**
 * Create a new directory on the file system.
 * @param path the path for the directory to be created.  (use / on all systems)
 * @param perm Permissions for the new direcoty.
 * @param cont the pool to use.
 * @deffunc apr_status_t apr_dir_make(const char *path, apr_fileperms_t perm, apr_pool_t *cont)
 */                        
APR_DECLARE(apr_status_t) apr_dir_make(const char *path, apr_fileperms_t perm, 
                        apr_pool_t *cont);

/**
 * Remove directory from the file system.
 * @param path the path for the directory to be removed.  (use / on all systems)
 * @param cont the pool to use.
 * @deffunc apr_status_t apr_dir_remove(const char *path, apr_pool_t *cont)
 */                        
APR_DECLARE(apr_status_t) apr_dir_remove(const char *path, apr_pool_t *cont);

/**
 * get the specified file's stats.
 * @param finfo Where to store the information about the file.
 * @param wanted The desired apr_finfo_t fields, as a bit flag of APR_FINFO_ values 
 * @param thefile The file to get information about.
 * @deffunc apr_status_t apr_file_info_get(apr_finfo_t *finfo, apr_int32_t wanted, apr_file_t *thefile)
 */ 
APR_DECLARE(apr_status_t) apr_file_info_get(apr_finfo_t *finfo, 
                                          apr_int32_t wanted,
                                          apr_file_t *thefile);


/**
 * Truncate the file's length to the specified offset
 * @param fp The file to truncate
 * @param offset The offset to truncate to.
 */
APR_DECLARE(apr_status_t) apr_file_trunc(apr_file_t *fp, apr_off_t offset);

/**
 * Get the pool used by the file.
 * @return apr_pool_t the pool
 * @deffunc apr_pool_t apr_file_pool_get(apr_file_t *f)
 */
APR_POOL_DECLARE_ACCESSOR(file);

#ifdef __cplusplus
}
#endif

#endif  /* ! APR_FILE_IO_H */