Apache Portable Runtime
apr_file_io.h
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00001 /* Licensed to the Apache Software Foundation (ASF) under one or more
00002  * contributor license agreements.  See the NOTICE file distributed with
00003  * this work for additional information regarding copyright ownership.
00004  * The ASF licenses this file to You under the Apache License, Version 2.0
00005  * (the "License"); you may not use this file except in compliance with
00006  * the License.  You may obtain a copy of the License at
00007  *
00008  *     http://www.apache.org/licenses/LICENSE-2.0
00009  *
00010  * Unless required by applicable law or agreed to in writing, software
00011  * distributed under the License is distributed on an "AS IS" BASIS,
00012  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00013  * See the License for the specific language governing permissions and
00014  * limitations under the License.
00015  */
00016 
00017 #ifndef APR_FILE_IO_H
00018 #define APR_FILE_IO_H
00019 
00020 /**
00021  * @file apr_file_io.h
00022  * @brief APR File I/O Handling
00023  */
00024 
00025 #include "apr.h"
00026 #include "apr_pools.h"
00027 #include "apr_time.h"
00028 #include "apr_errno.h"
00029 #include "apr_file_info.h"
00030 #include "apr_inherit.h"
00031 
00032 #define APR_WANT_STDIO          /**< for SEEK_* */
00033 #define APR_WANT_IOVEC          /**< for apr_file_writev */
00034 #include "apr_want.h"
00035 
00036 #ifdef __cplusplus
00037 extern "C" {
00038 #endif /* __cplusplus */
00039 
00040 /**
00041  * @defgroup apr_file_io File I/O Handling Functions
00042  * @ingroup APR 
00043  * @{
00044  */
00045 
00046 /**
00047  * @defgroup apr_file_open_flags File Open Flags/Routines
00048  * @{
00049  */
00050 
00051 /* Note to implementors: Values in the range 0x00100000--0x80000000
00052    are reserved for platform-specific values. */
00053 
00054 #define APR_FOPEN_READ       0x00001  /**< Open the file for reading */
00055 #define APR_FOPEN_WRITE      0x00002  /**< Open the file for writing */
00056 #define APR_FOPEN_CREATE     0x00004  /**< Create the file if not there */
00057 #define APR_FOPEN_APPEND     0x00008  /**< Append to the end of the file */
00058 #define APR_FOPEN_TRUNCATE   0x00010  /**< Open the file and truncate
00059                                          to 0 length */
00060 #define APR_FOPEN_BINARY     0x00020  /**< Open the file in binary mode
00061                                          (This flag is ignored on UNIX 
00062                                          because it has no meaning)*/
00063 #define APR_FOPEN_EXCL       0x00040  /**< Open should fail if #APR_FOPEN_CREATE
00064                                          and file exists. */
00065 #define APR_FOPEN_BUFFERED   0x00080  /**< Open the file for buffered I/O */
00066 #define APR_FOPEN_DELONCLOSE 0x00100  /**< Delete the file after close */
00067 #define APR_FOPEN_XTHREAD    0x00200  /**< Platform dependent tag to open
00068                                          the file for use across multiple
00069                                          threads */
00070 #define APR_FOPEN_SHARELOCK  0x00400  /**< Platform dependent support for
00071                                          higher level locked read/write
00072                                          access to support writes across
00073                                          process/machines */
00074 #define APR_FOPEN_NOCLEANUP  0x00800  /**< Do not register a cleanup
00075                                          when the file is opened. The
00076                                          apr_os_file_t handle in apr_file_t
00077                                          will not be closed when the pool
00078                                          is destroyed. */
00079 #define APR_FOPEN_SENDFILE_ENABLED 0x01000 /**< Advisory flag that this
00080                                              file should support
00081                                              apr_socket_sendfile operation */
00082 #define APR_FOPEN_LARGEFILE   0x04000 /**< Platform dependent flag to enable
00083                                        * large file support, see WARNING below
00084                                        */
00085 #define APR_FOPEN_SPARSE      0x08000 /**< Platform dependent flag to enable
00086                                        * sparse file support, see WARNING below
00087                                        */
00088 #define APR_FOPEN_NONBLOCK    0x40000 /**< Platform dependent flag to enable
00089                                        * non blocking file io */
00090 
00091 
00092 /* backcompat */
00093 #define APR_READ             APR_FOPEN_READ       /**< @deprecated @see APR_FOPEN_READ */
00094 #define APR_WRITE            APR_FOPEN_WRITE      /**< @deprecated @see APR_FOPEN_WRITE */   
00095 #define APR_CREATE           APR_FOPEN_CREATE     /**< @deprecated @see APR_FOPEN_CREATE */   
00096 #define APR_APPEND           APR_FOPEN_APPEND     /**< @deprecated @see APR_FOPEN_APPEND */   
00097 #define APR_TRUNCATE         APR_FOPEN_TRUNCATE   /**< @deprecated @see APR_FOPEN_TRUNCATE */   
00098 #define APR_BINARY           APR_FOPEN_BINARY     /**< @deprecated @see APR_FOPEN_BINARY */   
00099 #define APR_EXCL             APR_FOPEN_EXCL       /**< @deprecated @see APR_FOPEN_EXCL */   
00100 #define APR_BUFFERED         APR_FOPEN_BUFFERED   /**< @deprecated @see APR_FOPEN_BUFFERED */   
00101 #define APR_DELONCLOSE       APR_FOPEN_DELONCLOSE /**< @deprecated @see APR_FOPEN_DELONCLOSE */   
00102 #define APR_XTHREAD          APR_FOPEN_XTHREAD    /**< @deprecated @see APR_FOPEN_XTHREAD */   
00103 #define APR_SHARELOCK        APR_FOPEN_SHARELOCK  /**< @deprecated @see APR_FOPEN_SHARELOCK */   
00104 #define APR_FILE_NOCLEANUP   APR_FOPEN_NOCLEANUP  /**< @deprecated @see APR_FOPEN_NOCLEANUP */   
00105 #define APR_SENDFILE_ENABLED APR_FOPEN_SENDFILE_ENABLED /**< @deprecated @see APR_FOPEN_SENDFILE_ENABLED */   
00106 #define APR_LARGEFILE        APR_FOPEN_LARGEFILE  /**< @deprecated @see APR_FOPEN_LARGEFILE */   
00107 
00108 /** @def APR_FOPEN_LARGEFILE 
00109  * @warning APR_FOPEN_LARGEFILE flag only has effect on some
00110  * platforms where sizeof(apr_off_t) == 4.  Where implemented, it
00111  * allows opening and writing to a file which exceeds the size which
00112  * can be represented by apr_off_t (2 gigabytes).  When a file's size
00113  * does exceed 2Gb, apr_file_info_get() will fail with an error on the
00114  * descriptor, likewise apr_stat()/apr_lstat() will fail on the
00115  * filename.  apr_dir_read() will fail with #APR_INCOMPLETE on a
00116  * directory entry for a large file depending on the particular
00117  * APR_FINFO_* flags.  Generally, it is not recommended to use this
00118  * flag.
00119  *
00120  * @def APR_FOPEN_SPARSE
00121  * @warning APR_FOPEN_SPARSE may, depending on platform, convert a
00122  * normal file to a sparse file.  Some applications may be unable
00123  * to decipher a sparse file, so it's critical that the sparse file
00124  * flag should only be used for files accessed only by APR or other
00125  * applications known to be able to decipher them.  APR does not
00126  * guarantee that it will compress the file into sparse segments
00127  * if it was previously created and written without the sparse flag.
00128  * On platforms which do not understand, or on file systems which
00129  * cannot handle sparse files, the flag is ignored by apr_file_open().
00130  *
00131  * @def APR_FOPEN_NONBLOCK
00132  * @warning APR_FOPEN_NONBLOCK is not implemented on all platforms.
00133  * Callers should be prepared for it to fail with #APR_ENOTIMPL.
00134  */
00135 
00136 /** @} */
00137 
00138 /**
00139  * @defgroup apr_file_seek_flags File Seek Flags
00140  * @{
00141  */
00142 
00143 /* flags for apr_file_seek */
00144 /** Set the file position */
00145 #define APR_SET SEEK_SET
00146 /** Current */
00147 #define APR_CUR SEEK_CUR
00148 /** Go to end of file */
00149 #define APR_END SEEK_END
00150 /** @} */
00151 
00152 /**
00153  * @defgroup apr_file_attrs_set_flags File Attribute Flags
00154  * @{
00155  */
00156 
00157 /* flags for apr_file_attrs_set */
00158 #define APR_FILE_ATTR_READONLY   0x01          /**< File is read-only */
00159 #define APR_FILE_ATTR_EXECUTABLE 0x02          /**< File is executable */
00160 #define APR_FILE_ATTR_HIDDEN     0x04          /**< File is hidden */
00161 /** @} */
00162 
00163 /**
00164  * @defgroup apr_file_writev{_full} max iovec size
00165  * @{
00166  */
00167 #if defined(DOXYGEN)
00168 #define APR_MAX_IOVEC_SIZE 1024                /**< System dependent maximum 
00169                                                     size of an iovec array */
00170 #elif defined(IOV_MAX)
00171 #define APR_MAX_IOVEC_SIZE IOV_MAX
00172 #elif defined(MAX_IOVEC)
00173 #define APR_MAX_IOVEC_SIZE MAX_IOVEC
00174 #else
00175 #define APR_MAX_IOVEC_SIZE 1024
00176 #endif
00177 /** @} */
00178 
00179 /** File attributes */
00180 typedef apr_uint32_t apr_fileattrs_t;
00181 
00182 /** Type to pass as whence argument to apr_file_seek. */
00183 typedef int       apr_seek_where_t;
00184 
00185 /**
00186  * Structure for referencing files.
00187  */
00188 typedef struct apr_file_t         apr_file_t;
00189 
00190 /* File lock types/flags */
00191 /**
00192  * @defgroup apr_file_lock_types File Lock Types
00193  * @{
00194  */
00195 
00196 #define APR_FLOCK_SHARED        1       /**< Shared lock. More than one process
00197                                            or thread can hold a shared lock
00198                                            at any given time. Essentially,
00199                                            this is a "read lock", preventing
00200                                            writers from establishing an
00201                                            exclusive lock. */
00202 #define APR_FLOCK_EXCLUSIVE     2       /**< Exclusive lock. Only one process
00203                                            may hold an exclusive lock at any
00204                                            given time. This is analogous to
00205                                            a "write lock". */
00206 
00207 #define APR_FLOCK_TYPEMASK      0x000F  /**< mask to extract lock type */
00208 #define APR_FLOCK_NONBLOCK      0x0010  /**< do not block while acquiring the
00209                                            file lock */
00210 /** @} */
00211 
00212 /**
00213  * Open the specified file.
00214  * @param newf The opened file descriptor.
00215  * @param fname The full path to the file (using / on all systems)
00216  * @param flag Or'ed value of:
00217  * @li #APR_FOPEN_READ           open for reading
00218  * @li #APR_FOPEN_WRITE          open for writing
00219  * @li #APR_FOPEN_CREATE         create the file if not there
00220  * @li #APR_FOPEN_APPEND         file ptr is set to end prior to all writes
00221  * @li #APR_FOPEN_TRUNCATE       set length to zero if file exists
00222  * @li #APR_FOPEN_BINARY         not a text file
00223  * @li #APR_FOPEN_BUFFERED       buffer the data.  Default is non-buffered
00224  * @li #APR_FOPEN_EXCL           return error if #APR_FOPEN_CREATE and file exists
00225  * @li #APR_FOPEN_DELONCLOSE     delete the file after closing
00226  * @li #APR_FOPEN_XTHREAD        Platform dependent tag to open the file
00227  *                               for use across multiple threads
00228  * @li #APR_FOPEN_SHARELOCK      Platform dependent support for higher
00229  *                               level locked read/write access to support
00230  *                               writes across process/machines
00231  * @li #APR_FOPEN_NOCLEANUP      Do not register a cleanup with the pool 
00232  *                               passed in on the @a pool argument (see below)
00233  * @li #APR_FOPEN_SENDFILE_ENABLED  Open with appropriate platform semantics
00234  *                               for sendfile operations.  Advisory only,
00235  *                               apr_socket_sendfile does not check this flag
00236  * @li #APR_FOPEN_LARGEFILE      Platform dependent flag to enable large file
00237  *                               support, see WARNING below 
00238  * @li #APR_FOPEN_SPARSE         Platform dependent flag to enable sparse file
00239  *                               support, see WARNING below
00240  * @li #APR_FOPEN_NONBLOCK       Platform dependent flag to enable
00241  *                               non blocking file io
00242  * @param perm Access permissions for file.
00243  * @param pool The pool to use.
00244  * @remark If perm is #APR_FPROT_OS_DEFAULT and the file is being created,
00245  * appropriate default permissions will be used.
00246  * @remark By default, the returned file descriptor will not be
00247  * inherited by child processes created by apr_proc_create().  This
00248  * can be changed using apr_file_inherit_set().
00249  */
00250 APR_DECLARE(apr_status_t) apr_file_open(apr_file_t **newf, const char *fname,
00251                                         apr_int32_t flag, apr_fileperms_t perm,
00252                                         apr_pool_t *pool);
00253 
00254 /**
00255  * Close the specified file.
00256  * @param file The file descriptor to close.
00257  */
00258 APR_DECLARE(apr_status_t) apr_file_close(apr_file_t *file);
00259 
00260 /**
00261  * Delete the specified file.
00262  * @param path The full path to the file (using / on all systems)
00263  * @param pool The pool to use.
00264  * @remark If the file is open, it won't be removed until all
00265  * instances are closed.
00266  */
00267 APR_DECLARE(apr_status_t) apr_file_remove(const char *path, apr_pool_t *pool);
00268 
00269 /**
00270  * Rename the specified file.
00271  * @param from_path The full path to the original file (using / on all systems)
00272  * @param to_path The full path to the new file (using / on all systems)
00273  * @param pool The pool to use.
00274  * @warning If a file exists at the new location, then it will be
00275  * overwritten.  Moving files or directories across devices may not be
00276  * possible.
00277  */
00278 APR_DECLARE(apr_status_t) apr_file_rename(const char *from_path, 
00279                                           const char *to_path,
00280                                           apr_pool_t *pool);
00281 
00282 /**
00283  * Create a hard link to the specified file.
00284  * @param from_path The full path to the original file (using / on all systems)
00285  * @param to_path The full path to the new file (using / on all systems)
00286  * @remark Both files must reside on the same device.
00287  */
00288 APR_DECLARE(apr_status_t) apr_file_link(const char *from_path, 
00289                                           const char *to_path);
00290 
00291 /**
00292  * Copy the specified file to another file.
00293  * @param from_path The full path to the original file (using / on all systems)
00294  * @param to_path The full path to the new file (using / on all systems)
00295  * @param perms Access permissions for the new file if it is created.
00296  *     In place of the usual or'd combination of file permissions, the
00297  *     value #APR_FPROT_FILE_SOURCE_PERMS may be given, in which case the source
00298  *     file's permissions are copied.
00299  * @param pool The pool to use.
00300  * @remark The new file does not need to exist, it will be created if required.
00301  * @warning If the new file already exists, its contents will be overwritten.
00302  */
00303 APR_DECLARE(apr_status_t) apr_file_copy(const char *from_path, 
00304                                         const char *to_path,
00305                                         apr_fileperms_t perms,
00306                                         apr_pool_t *pool);
00307 
00308 /**
00309  * Append the specified file to another file.
00310  * @param from_path The full path to the source file (use / on all systems)
00311  * @param to_path The full path to the destination file (use / on all systems)
00312  * @param perms Access permissions for the destination file if it is created.
00313  *     In place of the usual or'd combination of file permissions, the
00314  *     value #APR_FPROT_FILE_SOURCE_PERMS may be given, in which case the source
00315  *     file's permissions are copied.
00316  * @param pool The pool to use.
00317  * @remark The new file does not need to exist, it will be created if required.
00318  */
00319 APR_DECLARE(apr_status_t) apr_file_append(const char *from_path, 
00320                                           const char *to_path,
00321                                           apr_fileperms_t perms,
00322                                           apr_pool_t *pool);
00323 
00324 /**
00325  * Are we at the end of the file
00326  * @param fptr The apr file we are testing.
00327  * @remark Returns #APR_EOF if we are at the end of file, #APR_SUCCESS otherwise.
00328  */
00329 APR_DECLARE(apr_status_t) apr_file_eof(apr_file_t *fptr);
00330 
00331 /**
00332  * Open standard error as an apr file pointer.
00333  * @param thefile The apr file to use as stderr.
00334  * @param pool The pool to allocate the file out of.
00335  * 
00336  * @remark The only reason that the apr_file_open_std* functions exist
00337  * is that you may not always have a stderr/out/in on Windows.  This
00338  * is generally a problem with newer versions of Windows and services.
00339  * 
00340  * @remark The other problem is that the C library functions generally work
00341  * differently on Windows and Unix.  So, by using apr_file_open_std*
00342  * functions, you can get a handle to an APR struct that works with
00343  * the APR functions which are supposed to work identically on all
00344  * platforms.
00345  */
00346 APR_DECLARE(apr_status_t) apr_file_open_stderr(apr_file_t **thefile,
00347                                                apr_pool_t *pool);
00348 
00349 /**
00350  * open standard output as an apr file pointer.
00351  * @param thefile The apr file to use as stdout.
00352  * @param pool The pool to allocate the file out of.
00353  * 
00354  * @remark See remarks for apr_file_open_stderr().
00355  */
00356 APR_DECLARE(apr_status_t) apr_file_open_stdout(apr_file_t **thefile,
00357                                                apr_pool_t *pool);
00358 
00359 /**
00360  * open standard input as an apr file pointer.
00361  * @param thefile The apr file to use as stdin.
00362  * @param pool The pool to allocate the file out of.
00363  * 
00364  * @remark See remarks for apr_file_open_stderr().
00365  */
00366 APR_DECLARE(apr_status_t) apr_file_open_stdin(apr_file_t **thefile,
00367                                               apr_pool_t *pool);
00368 
00369 /**
00370  * open standard error as an apr file pointer, with flags.
00371  * @param thefile The apr file to use as stderr.
00372  * @param flags The flags to open the file with. Only the 
00373  *              @li #APR_FOPEN_EXCL
00374  *              @li #APR_FOPEN_BUFFERED
00375  *              @li #APR_FOPEN_XTHREAD
00376  *              @li #APR_FOPEN_SHARELOCK 
00377  *              @li #APR_FOPEN_SENDFILE_ENABLED
00378  *              @li #APR_FOPEN_LARGEFILE
00379  *
00380  *              flags should be used. The #APR_FOPEN_WRITE flag will
00381  *              be set unconditionally.
00382  * @param pool The pool to allocate the file out of.
00383  * 
00384  * @remark See remarks for apr_file_open_stderr().
00385  */
00386 APR_DECLARE(apr_status_t) apr_file_open_flags_stderr(apr_file_t **thefile,
00387                                                      apr_int32_t flags,
00388                                                      apr_pool_t *pool);
00389 
00390 /**
00391  * open standard output as an apr file pointer, with flags.
00392  * @param thefile The apr file to use as stdout.
00393  * @param flags The flags to open the file with. Only the 
00394  *              @li #APR_FOPEN_EXCL
00395  *              @li #APR_FOPEN_BUFFERED
00396  *              @li #APR_FOPEN_XTHREAD
00397  *              @li #APR_FOPEN_SHARELOCK 
00398  *              @li #APR_FOPEN_SENDFILE_ENABLED
00399  *              @li #APR_FOPEN_LARGEFILE
00400  *
00401  *              flags should be used. The #APR_FOPEN_WRITE flag will
00402  *              be set unconditionally.
00403  * @param pool The pool to allocate the file out of.
00404  * 
00405  * @remark See remarks for apr_file_open_stderr().
00406  */
00407 APR_DECLARE(apr_status_t) apr_file_open_flags_stdout(apr_file_t **thefile,
00408                                                      apr_int32_t flags,
00409                                                      apr_pool_t *pool);
00410 
00411 /**
00412  * open standard input as an apr file pointer, with flags.
00413  * @param thefile The apr file to use as stdin.
00414  * @param flags The flags to open the file with. Only the 
00415  *              @li #APR_FOPEN_EXCL
00416  *              @li #APR_FOPEN_BUFFERED
00417  *              @li #APR_FOPEN_XTHREAD
00418  *              @li #APR_FOPEN_SHARELOCK 
00419  *              @li #APR_FOPEN_SENDFILE_ENABLED
00420  *              @li #APR_FOPEN_LARGEFILE
00421  *
00422  *              flags should be used. The #APR_FOPEN_WRITE flag will
00423  *              be set unconditionally.
00424  * @param pool The pool to allocate the file out of.
00425  * 
00426  * @remark See remarks for apr_file_open_stderr().
00427  */
00428 APR_DECLARE(apr_status_t) apr_file_open_flags_stdin(apr_file_t **thefile,
00429                                                      apr_int32_t flags,
00430                                                      apr_pool_t *pool);
00431 
00432 /**
00433  * Read data from the specified file.
00434  * @param thefile The file descriptor to read from.
00435  * @param buf The buffer to store the data to.
00436  * @param nbytes On entry, the number of bytes to read; on exit, the number
00437  * of bytes read.
00438  *
00439  * @remark apr_file_read() will read up to the specified number of
00440  * bytes, but never more.  If there isn't enough data to fill that
00441  * number of bytes, all of the available data is read.  The third
00442  * argument is modified to reflect the number of bytes read.  If a
00443  * char was put back into the stream via ungetc, it will be the first
00444  * character returned.
00445  *
00446  * @remark It is not possible for both bytes to be read and an #APR_EOF
00447  * or other error to be returned.  #APR_EINTR is never returned.
00448  */
00449 APR_DECLARE(apr_status_t) apr_file_read(apr_file_t *thefile, void *buf,
00450                                         apr_size_t *nbytes);
00451 
00452 /**
00453  * Write data to the specified file.
00454  * @param thefile The file descriptor to write to.
00455  * @param buf The buffer which contains the data.
00456  * @param nbytes On entry, the number of bytes to write; on exit, the number 
00457  *               of bytes written.
00458  *
00459  * @remark apr_file_write() will write up to the specified number of
00460  * bytes, but never more.  If the OS cannot write that many bytes, it
00461  * will write as many as it can.  The third argument is modified to
00462  * reflect the * number of bytes written.
00463  *
00464  * @remark It is possible for both bytes to be written and an error to
00465  * be returned.  #APR_EINTR is never returned.
00466  */
00467 APR_DECLARE(apr_status_t) apr_file_write(apr_file_t *thefile, const void *buf,
00468                                          apr_size_t *nbytes);
00469 
00470 /**
00471  * Write data from iovec array to the specified file.
00472  * @param thefile The file descriptor to write to.
00473  * @param vec The array from which to get the data to write to the file.
00474  * @param nvec The number of elements in the struct iovec array. This must 
00475  *             be smaller than #APR_MAX_IOVEC_SIZE.  If it isn't, the function 
00476  *             will fail with #APR_EINVAL.
00477  * @param nbytes The number of bytes written.
00478  *
00479  * @remark It is possible for both bytes to be written and an error to
00480  * be returned.  #APR_EINTR is never returned.
00481  *
00482  * @remark apr_file_writev() is available even if the underlying
00483  * operating system doesn't provide writev().
00484  */
00485 APR_DECLARE(apr_status_t) apr_file_writev(apr_file_t *thefile,
00486                                           const struct iovec *vec,
00487                                           apr_size_t nvec, apr_size_t *nbytes);
00488 
00489 /**
00490  * Read data from the specified file, ensuring that the buffer is filled
00491  * before returning.
00492  * @param thefile The file descriptor to read from.
00493  * @param buf The buffer to store the data to.
00494  * @param nbytes The number of bytes to read.
00495  * @param bytes_read If non-NULL, this will contain the number of bytes read.
00496  *
00497  * @remark apr_file_read_full() will read up to the specified number of
00498  * bytes, but never more.  If there isn't enough data to fill that
00499  * number of bytes, then the process/thread will block until it is
00500  * available or EOF is reached.  If a char was put back into the
00501  * stream via ungetc, it will be the first character returned.
00502  *
00503  * @remark It is possible for both bytes to be read and an error to be
00504  * returned.  And if *bytes_read is less than nbytes, an accompanying
00505  * error is _always_ returned.
00506  *
00507  * @remark #APR_EINTR is never returned.
00508  */
00509 APR_DECLARE(apr_status_t) apr_file_read_full(apr_file_t *thefile, void *buf,
00510                                              apr_size_t nbytes,
00511                                              apr_size_t *bytes_read);
00512 
00513 /**
00514  * Write data to the specified file, ensuring that all of the data is
00515  * written before returning.
00516  * @param thefile The file descriptor to write to.
00517  * @param buf The buffer which contains the data.
00518  * @param nbytes The number of bytes to write.
00519  * @param bytes_written If non-NULL, set to the number of bytes written.
00520  * 
00521  * @remark apr_file_write_full() will write up to the specified number of
00522  * bytes, but never more.  If the OS cannot write that many bytes, the
00523  * process/thread will block until they can be written. Exceptional
00524  * error such as "out of space" or "pipe closed" will terminate with
00525  * an error.
00526  *
00527  * @remark It is possible for both bytes to be written and an error to
00528  * be returned.  And if *bytes_written is less than nbytes, an
00529  * accompanying error is _always_ returned.
00530  *
00531  * @remark #APR_EINTR is never returned.
00532  */
00533 APR_DECLARE(apr_status_t) apr_file_write_full(apr_file_t *thefile, 
00534                                               const void *buf,
00535                                               apr_size_t nbytes, 
00536                                               apr_size_t *bytes_written);
00537 
00538 
00539 /**
00540  * Write data from iovec array to the specified file, ensuring that all of the
00541  * data is written before returning.
00542  * @param thefile The file descriptor to write to.
00543  * @param vec The array from which to get the data to write to the file.
00544  * @param nvec The number of elements in the struct iovec array. This must 
00545  *             be smaller than #APR_MAX_IOVEC_SIZE.  If it isn't, the function 
00546  *             will fail with #APR_EINVAL.
00547  * @param nbytes The number of bytes written.
00548  *
00549  * @remark apr_file_writev_full() is available even if the underlying
00550  * operating system doesn't provide writev().
00551  */
00552 APR_DECLARE(apr_status_t) apr_file_writev_full(apr_file_t *thefile,
00553                                                const struct iovec *vec,
00554                                                apr_size_t nvec,
00555                                                apr_size_t *nbytes);
00556 /**
00557  * Write a character into the specified file.
00558  * @param ch The character to write.
00559  * @param thefile The file descriptor to write to
00560  */
00561 APR_DECLARE(apr_status_t) apr_file_putc(char ch, apr_file_t *thefile);
00562 
00563 /**
00564  * Read a character from the specified file.
00565  * @param ch The character to read into
00566  * @param thefile The file descriptor to read from
00567  */
00568 APR_DECLARE(apr_status_t) apr_file_getc(char *ch, apr_file_t *thefile);
00569 
00570 /**
00571  * Put a character back onto a specified stream.
00572  * @param ch The character to write.
00573  * @param thefile The file descriptor to write to
00574  */
00575 APR_DECLARE(apr_status_t) apr_file_ungetc(char ch, apr_file_t *thefile);
00576 
00577 /**
00578  * Read a line from the specified file
00579  * @param str The buffer to store the string in. 
00580  * @param len The length of the string
00581  * @param thefile The file descriptor to read from
00582  * @remark The buffer will be NUL-terminated if any characters are stored.
00583  *         The newline at the end of the line will not be stripped.
00584  */
00585 APR_DECLARE(apr_status_t) apr_file_gets(char *str, int len, 
00586                                         apr_file_t *thefile);
00587 
00588 /**
00589  * Write the string into the specified file.
00590  * @param str The string to write. 
00591  * @param thefile The file descriptor to write to
00592  */
00593 APR_DECLARE(apr_status_t) apr_file_puts(const char *str, apr_file_t *thefile);
00594 
00595 /**
00596  * Flush the file's buffer.
00597  * @param thefile The file descriptor to flush
00598  */
00599 APR_DECLARE(apr_status_t) apr_file_flush(apr_file_t *thefile);
00600 
00601 /**
00602  * Transfer all file modified data and metadata to disk.
00603  * @param thefile The file descriptor to sync
00604  */
00605 APR_DECLARE(apr_status_t) apr_file_sync(apr_file_t *thefile);
00606 
00607 /**
00608  * Transfer all file modified data to disk.
00609  * @param thefile The file descriptor to sync
00610  */
00611 APR_DECLARE(apr_status_t) apr_file_datasync(apr_file_t *thefile);
00612 
00613 /**
00614  * Duplicate the specified file descriptor.
00615  * @param new_file The structure to duplicate into. 
00616  * @param old_file The file to duplicate.
00617  * @param p The pool to use for the new file.
00618  * @remark *new_file must point to a valid apr_file_t, or point to NULL.
00619  */         
00620 APR_DECLARE(apr_status_t) apr_file_dup(apr_file_t **new_file,
00621                                        apr_file_t *old_file,
00622                                        apr_pool_t *p);
00623 
00624 /**
00625  * Duplicate the specified file descriptor and close the original
00626  * @param new_file The old file that is to be closed and reused
00627  * @param old_file The file to duplicate
00628  * @param p        The pool to use for the new file
00629  *
00630  * @remark new_file MUST point at a valid apr_file_t. It cannot be NULL.
00631  */
00632 APR_DECLARE(apr_status_t) apr_file_dup2(apr_file_t *new_file,
00633                                         apr_file_t *old_file,
00634                                         apr_pool_t *p);
00635 
00636 /**
00637  * Move the specified file descriptor to a new pool
00638  * @param new_file Pointer in which to return the new apr_file_t
00639  * @param old_file The file to move
00640  * @param p        The pool to which the descriptor is to be moved
00641  * @remark Unlike apr_file_dup2(), this function doesn't do an
00642  *         OS dup() operation on the underlying descriptor; it just
00643  *         moves the descriptor's apr_file_t wrapper to a new pool.
00644  * @remark The new pool need not be an ancestor of old_file's pool.
00645  * @remark After calling this function, old_file may not be used
00646  */
00647 APR_DECLARE(apr_status_t) apr_file_setaside(apr_file_t **new_file,
00648                                             apr_file_t *old_file,
00649                                             apr_pool_t *p);
00650 
00651 /**
00652  * Give the specified apr file handle a new buffer 
00653  * @param thefile  The file handle that is to be modified
00654  * @param buffer   The buffer
00655  * @param bufsize  The size of the buffer
00656  * @remark It is possible to add a buffer to previously unbuffered
00657  *         file handles, the #APR_FOPEN_BUFFERED flag will be added to
00658  *         the file handle's flags. Likewise, with buffer=NULL and
00659  *         bufsize=0 arguments it is possible to make a previously
00660  *         buffered file handle unbuffered.
00661  */
00662 APR_DECLARE(apr_status_t) apr_file_buffer_set(apr_file_t *thefile,
00663                                               char * buffer,
00664                                               apr_size_t bufsize);
00665 
00666 /**
00667  * Get the size of any buffer for the specified apr file handle 
00668  * @param thefile  The file handle 
00669  */
00670 APR_DECLARE(apr_size_t) apr_file_buffer_size_get(apr_file_t *thefile);
00671 
00672 /**
00673  * Move the read/write file offset to a specified byte within a file.
00674  * @param thefile The file descriptor
00675  * @param where How to move the pointer, one of:
00676  *              @li #APR_SET  --  set the offset to offset
00677  *              @li #APR_CUR  --  add the offset to the current position 
00678  *              @li #APR_END  --  add the offset to the current file size 
00679  * @param offset The offset to move the pointer to.
00680  * @remark The third argument is modified to be the offset the pointer
00681           was actually moved to.
00682  */
00683 APR_DECLARE(apr_status_t) apr_file_seek(apr_file_t *thefile, 
00684                                    apr_seek_where_t where,
00685                                    apr_off_t *offset);
00686 
00687 /**
00688  * Create an anonymous pipe.
00689  * @param in The newly created pipe's file for reading.
00690  * @param out The newly created pipe's file for writing.
00691  * @param pool The pool to operate on.
00692  * @remark By default, the returned file descriptors will be inherited
00693  * by child processes created using apr_proc_create().  This can be
00694  * changed using apr_file_inherit_unset().
00695  * @bug  Some platforms cannot toggle between blocking and nonblocking,
00696  * and when passing a pipe as a standard handle to an application which
00697  * does not expect it, a non-blocking stream will fluxor the client app.
00698  * @deprecated @see apr_file_pipe_create_ex()
00699  */
00700 APR_DECLARE(apr_status_t) apr_file_pipe_create(apr_file_t **in, 
00701                                                apr_file_t **out,
00702                                                apr_pool_t *pool);
00703 
00704 /**
00705  * Create an anonymous pipe which portably supports async timeout options.
00706  * @param in The newly created pipe's file for reading.
00707  * @param out The newly created pipe's file for writing.
00708  * @param blocking one of these values defined in apr_thread_proc.h;
00709  *                 @li #APR_FULL_BLOCK
00710  *                 @li #APR_READ_BLOCK
00711  *                 @li #APR_WRITE_BLOCK
00712  *                 @li #APR_FULL_NONBLOCK
00713  * @param pool The pool to operate on.
00714  * @remark By default, the returned file descriptors will be inherited
00715  * by child processes created using apr_proc_create().  This can be
00716  * changed using apr_file_inherit_unset().
00717  * @remark Some platforms cannot toggle between blocking and nonblocking,
00718  * and when passing a pipe as a standard handle to an application which
00719  * does not expect it, a non-blocking stream will fluxor the client app.
00720  * Use this function rather than apr_file_pipe_create() to create pipes 
00721  * where one or both ends require non-blocking semantics.
00722  */
00723 APR_DECLARE(apr_status_t) apr_file_pipe_create_ex(apr_file_t **in, 
00724                                                   apr_file_t **out, 
00725                                                   apr_int32_t blocking, 
00726                                                   apr_pool_t *pool);
00727 
00728 /**
00729  * Create a named pipe.
00730  * @param filename The filename of the named pipe
00731  * @param perm The permissions for the newly created pipe.
00732  * @param pool The pool to operate on.
00733  */
00734 APR_DECLARE(apr_status_t) apr_file_namedpipe_create(const char *filename, 
00735                                                     apr_fileperms_t perm, 
00736                                                     apr_pool_t *pool);
00737 
00738 /**
00739  * Get the timeout value for a pipe or manipulate the blocking state.
00740  * @param thepipe The pipe we are getting a timeout for.
00741  * @param timeout The current timeout value in microseconds. 
00742  */
00743 APR_DECLARE(apr_status_t) apr_file_pipe_timeout_get(apr_file_t *thepipe, 
00744                                                apr_interval_time_t *timeout);
00745 
00746 /**
00747  * Set the timeout value for a pipe or manipulate the blocking state.
00748  * @param thepipe The pipe we are setting a timeout on.
00749  * @param timeout The timeout value in microseconds.  Values < 0 mean wait 
00750  *        forever, 0 means do not wait at all.
00751  */
00752 APR_DECLARE(apr_status_t) apr_file_pipe_timeout_set(apr_file_t *thepipe, 
00753                                                   apr_interval_time_t timeout);
00754 
00755 /** file (un)locking functions. */
00756 
00757 /**
00758  * Establish a lock on the specified, open file. The lock may be advisory
00759  * or mandatory, at the discretion of the platform. The lock applies to
00760  * the file as a whole, rather than a specific range. Locks are established
00761  * on a per-thread/process basis; a second lock by the same thread will not
00762  * block.
00763  * @param thefile The file to lock.
00764  * @param type The type of lock to establish on the file.
00765  */
00766 APR_DECLARE(apr_status_t) apr_file_lock(apr_file_t *thefile, int type);
00767 
00768 /**
00769  * Remove any outstanding locks on the file.
00770  * @param thefile The file to unlock.
00771  */
00772 APR_DECLARE(apr_status_t) apr_file_unlock(apr_file_t *thefile);
00773 
00774 /**accessor and general file_io functions. */
00775 
00776 /**
00777  * return the file name of the current file.
00778  * @param new_path The path of the file.  
00779  * @param thefile The currently open file.
00780  */                     
00781 APR_DECLARE(apr_status_t) apr_file_name_get(const char **new_path, 
00782                                             apr_file_t *thefile);
00783     
00784 /**
00785  * Return the data associated with the current file.
00786  * @param data The user data associated with the file.  
00787  * @param key The key to use for retrieving data associated with this file.
00788  * @param file The currently open file.
00789  */                     
00790 APR_DECLARE(apr_status_t) apr_file_data_get(void **data, const char *key, 
00791                                             apr_file_t *file);
00792 
00793 /**
00794  * Set the data associated with the current file.
00795  * @param file The currently open file.
00796  * @param data The user data to associate with the file.  
00797  * @param key The key to use for associating data with the file.
00798  * @param cleanup The cleanup routine to use when the file is destroyed.
00799  */                     
00800 APR_DECLARE(apr_status_t) apr_file_data_set(apr_file_t *file, void *data,
00801                                             const char *key,
00802                                             apr_status_t (*cleanup)(void *));
00803 
00804 /**
00805  * Write a string to a file using a printf format.
00806  * @param fptr The file to write to.
00807  * @param format The format string
00808  * @param ... The values to substitute in the format string
00809  * @return The number of bytes written
00810  */ 
00811 APR_DECLARE_NONSTD(int) apr_file_printf(apr_file_t *fptr, 
00812                                         const char *format, ...)
00813         __attribute__((format(printf,2,3)));
00814 
00815 /**
00816  * set the specified file's permission bits.
00817  * @param fname The file (name) to apply the permissions to.
00818  * @param perms The permission bits to apply to the file.
00819  *
00820  * @warning Some platforms may not be able to apply all of the
00821  * available permission bits; #APR_INCOMPLETE will be returned if some
00822  * permissions are specified which could not be set.
00823  *
00824  * @warning Platforms which do not implement this feature will return
00825  * #APR_ENOTIMPL.
00826  */
00827 APR_DECLARE(apr_status_t) apr_file_perms_set(const char *fname,
00828                                              apr_fileperms_t perms);
00829 
00830 /**
00831  * Set attributes of the specified file.
00832  * @param fname The full path to the file (using / on all systems)
00833  * @param attributes Or'd combination of
00834  *            @li #APR_FILE_ATTR_READONLY   - make the file readonly
00835  *            @li #APR_FILE_ATTR_EXECUTABLE - make the file executable
00836  *            @li #APR_FILE_ATTR_HIDDEN     - make the file hidden
00837  * @param attr_mask Mask of valid bits in attributes.
00838  * @param pool the pool to use.
00839  * @remark This function should be used in preference to explicit manipulation
00840  *      of the file permissions, because the operations to provide these
00841  *      attributes are platform specific and may involve more than simply
00842  *      setting permission bits.
00843  * @warning Platforms which do not implement this feature will return
00844  *      #APR_ENOTIMPL.
00845  */
00846 APR_DECLARE(apr_status_t) apr_file_attrs_set(const char *fname,
00847                                              apr_fileattrs_t attributes,
00848                                              apr_fileattrs_t attr_mask,
00849                                              apr_pool_t *pool);
00850 
00851 /**
00852  * Set the mtime of the specified file.
00853  * @param fname The full path to the file (using / on all systems)
00854  * @param mtime The mtime to apply to the file.
00855  * @param pool The pool to use.
00856  * @warning Platforms which do not implement this feature will return
00857  *      #APR_ENOTIMPL.
00858  */
00859 APR_DECLARE(apr_status_t) apr_file_mtime_set(const char *fname,
00860                                              apr_time_t mtime,
00861                                              apr_pool_t *pool);
00862 
00863 /**
00864  * Create a new directory on the file system.
00865  * @param path the path for the directory to be created. (use / on all systems)
00866  * @param perm Permissions for the new directory.
00867  * @param pool the pool to use.
00868  */                        
00869 APR_DECLARE(apr_status_t) apr_dir_make(const char *path, apr_fileperms_t perm, 
00870                                        apr_pool_t *pool);
00871 
00872 /** Creates a new directory on the file system, but behaves like
00873  * 'mkdir -p'. Creates intermediate directories as required. No error
00874  * will be reported if PATH already exists.
00875  * @param path the path for the directory to be created. (use / on all systems)
00876  * @param perm Permissions for the new directory.
00877  * @param pool the pool to use.
00878  */
00879 APR_DECLARE(apr_status_t) apr_dir_make_recursive(const char *path,
00880                                                  apr_fileperms_t perm,
00881                                                  apr_pool_t *pool);
00882 
00883 /**
00884  * Remove directory from the file system.
00885  * @param path the path for the directory to be removed. (use / on all systems)
00886  * @param pool the pool to use.
00887  * @remark Removing a directory which is in-use (e.g., the current working
00888  * directory, or during apr_dir_read, or with an open file) is not portable.
00889  */                        
00890 APR_DECLARE(apr_status_t) apr_dir_remove(const char *path, apr_pool_t *pool);
00891 
00892 /**
00893  * get the specified file's stats.
00894  * @param finfo Where to store the information about the file.
00895  * @param wanted The desired apr_finfo_t fields, as a bit flag of APR_FINFO_* values 
00896  * @param thefile The file to get information about.
00897  */ 
00898 APR_DECLARE(apr_status_t) apr_file_info_get(apr_finfo_t *finfo, 
00899                                             apr_int32_t wanted,
00900                                             apr_file_t *thefile);
00901     
00902 
00903 /**
00904  * Truncate the file's length to the specified offset
00905  * @param fp The file to truncate
00906  * @param offset The offset to truncate to.
00907  * @remark The read/write file offset is repositioned to offset.
00908  */
00909 APR_DECLARE(apr_status_t) apr_file_trunc(apr_file_t *fp, apr_off_t offset);
00910 
00911 /**
00912  * Retrieve the flags that were passed into apr_file_open()
00913  * when the file was opened.
00914  * @return apr_int32_t the flags
00915  */
00916 APR_DECLARE(apr_int32_t) apr_file_flags_get(apr_file_t *f);
00917 
00918 /**
00919  * Get the pool used by the file.
00920  */
00921 APR_POOL_DECLARE_ACCESSOR(file);
00922 
00923 /**
00924  * Set a file to be inherited by child processes.
00925  *
00926  */
00927 APR_DECLARE_INHERIT_SET(file);
00928 
00929 /**
00930  * Unset a file from being inherited by child processes.
00931  */
00932 APR_DECLARE_INHERIT_UNSET(file);
00933 
00934 /**
00935  * Open a temporary file
00936  * @param fp The apr file to use as a temporary file.
00937  * @param templ The template to use when creating a temp file.
00938  * @param flags The flags to open the file with. If this is zero,
00939  *              the file is opened with 
00940  *              #APR_FOPEN_CREATE | #APR_FOPEN_READ | #APR_FOPEN_WRITE |
00941  *              #APR_FOPEN_EXCL | #APR_FOPEN_DELONCLOSE
00942  * @param p The pool to allocate the file out of.
00943  * @remark   
00944  * This function  generates  a unique temporary file name from template.  
00945  * The last six characters of template must be XXXXXX and these are replaced 
00946  * with a string that makes the filename unique. Since it will  be  modified,
00947  * template must not be a string constant, but should be declared as a character
00948  * array.  
00949  *
00950  */
00951 APR_DECLARE(apr_status_t) apr_file_mktemp(apr_file_t **fp, char *templ,
00952                                           apr_int32_t flags, apr_pool_t *p);
00953 
00954 
00955 /**
00956  * Find an existing directory suitable as a temporary storage location.
00957  * @param temp_dir The temp directory.
00958  * @param p The pool to use for any necessary allocations.
00959  * @remark   
00960  * This function uses an algorithm to search for a directory that an
00961  * an application can use for temporary storage.
00962  *
00963  */
00964 APR_DECLARE(apr_status_t) apr_temp_dir_get(const char **temp_dir, 
00965                                            apr_pool_t *p);
00966 
00967 /** @} */
00968 
00969 #ifdef __cplusplus
00970 }
00971 #endif
00972 
00973 #endif  /* ! APR_FILE_IO_H */
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