bind9/lib/isc/include/isc/file.h
2004-03-09 06:12:49 +00:00

246 lines
7.1 KiB
C

/*
* Copyright (C) 2004 Internet Systems Consortium, Inc. ("ISC")
* Copyright (C) 2000, 2001 Internet Software Consortium.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: file.h,v 1.24.2.1 2004/03/09 06:11:55 marka Exp $ */
#ifndef ISC_FILE_H
#define ISC_FILE_H 1
#include <stdio.h>
#include <isc/lang.h>
#include <isc/types.h>
ISC_LANG_BEGINDECLS
isc_result_t
isc_file_settime(const char *file, isc_time_t *time);
isc_result_t
isc_file_getmodtime(const char *file, isc_time_t *time);
/*
* Get the time of last modication of a file.
*
* Notes:
* The time that is set is relative to the (OS-specific) epoch, as are
* all isc_time_t structures.
*
* Requires:
* file != NULL.
* time != NULL.
*
* Ensures:
* If the file could not be accessed, 'time' is unchanged.
*
* Returns:
* ISC_R_SUCCESS
* Success.
* ISC_R_NOTFOUND
* No such file exists.
* ISC_R_INVALIDFILE
* The path specified was not usable by the operating system.
* ISC_R_NOPERM
* The file's metainformation could not be retrieved because
* permission was denied to some part of the file's path.
* ISC_R_EIO
* Hardware error interacting with the filesystem.
* ISC_R_UNEXPECTED
* Something totally unexpected happened.
*
*/
isc_result_t
isc_file_mktemplate(const char *path, char *buf, size_t buflen);
/*
* Generate a template string suitable for use with isc_file_openunique.
*
* Notes:
* This function is intended to make creating temporary files
* portable between different operating systems.
*
* The path is prepended to an implementation-defined string and
* placed into buf. The string has no path characters in it,
* and its maximum length is 14 characters plus a NUL. Thus
* buflen should be at least strlen(path) + 15 characters or
* an error will be returned.
*
* Requires:
* buf != NULL.
*
* Ensures:
* If result == ISC_R_SUCCESS:
* buf contains a string suitable for use as the template argument
* to isc_file_openunique.
*
* If result != ISC_R_SUCCESS:
* buf is unchanged.
*
* Returns:
* ISC_R_SUCCESS Success.
* ISC_R_NOSPACE buflen indicates buf is too small for the catenation
* of the path with the internal template string.
*/
isc_result_t
isc_file_openunique(char *templet, FILE **fp);
/*
* Create and open a file with a unique name based on 'templet'.
*
* Notes:
* 'template' is a reserved work in C++. If you want to complain
* about the spelling of 'templet', first look it up in the
* Merriam-Webster English dictionary. (http://www.m-w.com/)
*
* This function works by using the template to generate file names.
* The template must be a writable string, as it is modified in place.
* Trailing X characters in the file name (full file name on Unix,
* basename on Win32 -- eg, tmp-XXXXXX vs XXXXXX.tmp, respectively)
* are replaced with ASCII characters until a non-existent filename
* is found. If the template does not include pathname information,
* the files in the working directory of the program are searched.
*
* isc_file_mktemplate is a good, portable way to get a template.
*
* Requires:
* 'fp' is non-NULL and '*fp' is NULL.
*
* 'template' is non-NULL, and of a form suitable for use by
* the system as described above.
*
* Ensures:
* If result is ISC_R_SUCCESS:
* *fp points to an stream opening in stdio's "w+" mode.
*
* If result is not ISC_R_SUCCESS:
* *fp is NULL.
*
* No file is open. Even if one was created (but unable
* to be reopened as a stdio FILE pointer) then it has been
* removed.
*
* This function does *not* ensure that the template string has not been
* modified, even if the operation was unsuccessful.
*
* Returns:
* ISC_R_SUCCESS
* Success.
* ISC_R_EXISTS
* No file with a unique name could be created based on the
* template.
* ISC_R_INVALIDFILE
* The path specified was not usable by the operating system.
* ISC_R_NOPERM
* The file could not be created because permission was denied
* to some part of the file's path.
* ISC_R_EIO
* Hardware error interacting with the filesystem.
* ISC_R_UNEXPECTED
* Something totally unexpected happened.
*/
isc_result_t
isc_file_remove(const char *filename);
/*
* Remove the file named by 'filename'.
*/
isc_result_t
isc_file_rename(const char *oldname, const char *newname);
/*
* Rename the file 'oldname' to 'newname'.
*/
isc_boolean_t
isc_file_exists(const char *pathname);
/*
* Return ISC_TRUE iff the calling process can tell that the given file exists.
* Will not return true if the calling process has insufficient privileges
* to search the entire path.
*/
isc_boolean_t
isc_file_isabsolute(const char *filename);
/*
* Return ISC_TRUE iff the given file name is absolute.
*/
isc_boolean_t
isc_file_iscurrentdir(const char *filename);
/*
* Return ISC_TRUE iff the given file name is the current directory (".").
*/
isc_boolean_t
isc_file_ischdiridempotent(const char *filename);
/*
* Return ISC_TRUE if calling chdir(filename) multiple times will give
* the same result as calling it once.
*/
const char *
isc_file_basename(const char *filename);
/*
* Return the final component of the path in the file name.
*/
isc_result_t
isc_file_progname(const char *filename, char *buf, size_t buflen);
/*
* Given an operating system specific file name "filename"
* referring to a program, return the canonical program name.
* Any directory prefix or executable file name extension (if
* used on the OS in case) is stripped. On systems where program
* names are case insensitive, the name is canonicalized to all
* lower case. The name is written to 'buf', an array of 'buflen'
* chars, and null terminated.
*
* Returns:
* ISC_R_SUCCESS
* ISC_R_NOSPACE The name did not fit in 'buf'.
*/
isc_result_t
isc_file_template(const char *path, const char *templet, char *buf,
size_t buflen);
/*
* Create an OS specific template using 'path' to define the directory
* 'templet' to describe the filename and store the result in 'buf'
* such that path can be renamed to buf atomically.
*/
isc_result_t
isc_file_renameunique(const char *file, char *templet);
/*
* Rename 'file' using 'templet' as a template for the new file name.
*/
isc_result_t
isc_file_absolutepath(const char *filename, char *path, size_t pathlen);
/*
* Given a file name, return the fully qualified path to the file.
*/
/*
* XXX We should also have a isc_file_writeeopen() function
* for safely open a file in a publicly writable directory
* (see write_open() in BIND 8's ns_config.c).
*/
ISC_LANG_ENDDECLS
#endif /* ISC_FILE_H */