Editing: file.h
/* * Copyright (C) Internet Systems Consortium, Inc. ("ISC") * * This Source Code Form is subject to the terms of the Mozilla Public * License, v. 2.0. If a copy of the MPL was not distributed with this * file, you can obtain one at https://mozilla.org/MPL/2.0/. * * See the COPYRIGHT file distributed with this work for additional * information regarding copyright ownership. */ #ifndef ISC_FILE_H #define ISC_FILE_H 1 /*! \file isc/file.h */ #include <stdbool.h> #include <stdio.h> #include <isc/lang.h> #include <isc/stat.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_mode(const char *file, mode_t *modep); isc_result_t isc_file_getmodtime(const char *file, isc_time_t *time); /*!< * \brief Get the time of last modification of a file. * * Notes: *\li The time that is set is relative to the (OS-specific) epoch, as are * all isc_time_t structures. * * Requires: *\li file != NULL. *\li time != NULL. * * Ensures: *\li If the file could not be accessed, 'time' is unchanged. * * Returns: *\li #ISC_R_SUCCESS * Success. *\li #ISC_R_NOTFOUND * No such file exists. *\li #ISC_R_INVALIDFILE * The path specified was not usable by the operating system. *\li #ISC_R_NOPERM * The file's metainformation could not be retrieved because * permission was denied to some part of the file's path. *\li #ISC_R_IOERROR * Hardware error interacting with the filesystem. *\li #ISC_R_UNEXPECTED * Something totally unexpected happened. * */ isc_result_t isc_file_mktemplate(const char *path, char *buf, size_t buflen); /*!< * \brief Generate a template string suitable for use with isc_file_openunique(). * * Notes: *\li This function is intended to make creating temporary files * portable between different operating systems. * *\li 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: *\li buf != NULL. * * Ensures: *\li If result == #ISC_R_SUCCESS: * buf contains a string suitable for use as the template argument * to isc_file_openunique(). * *\li If result != #ISC_R_SUCCESS: * buf is unchanged. * * Returns: *\li #ISC_R_SUCCESS Success. *\li #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); isc_result_t isc_file_openuniqueprivate(char *templet, FILE **fp); isc_result_t isc_file_openuniquemode(char *templet, int mode, FILE **fp); isc_result_t isc_file_bopenunique(char *templet, FILE **fp); isc_result_t isc_file_bopenuniqueprivate(char *templet, FILE **fp); isc_result_t isc_file_bopenuniquemode(char *templet, int mode, FILE **fp); /*!< * \brief Create and open a file with a unique name based on 'templet'. * isc_file_bopen*() open the file in binary mode in Windows. * isc_file_open*() open the file in text mode in Windows. * * Notes: *\li '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/) * *\li 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. * *\li isc_file_mktemplate is a good, portable way to get a template. * * Requires: *\li 'fp' is non-NULL and '*fp' is NULL. * *\li 'template' is non-NULL, and of a form suitable for use by * the system as described above. * * Ensures: *\li If result is #ISC_R_SUCCESS: * *fp points to an stream opening in stdio's "w+" mode. * *\li 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. * *\li This function does *not* ensure that the template string has not been * modified, even if the operation was unsuccessful. * * Returns: *\li #ISC_R_SUCCESS * Success. *\li #ISC_R_EXISTS * No file with a unique name could be created based on the * template. *\li #ISC_R_INVALIDFILE * The path specified was not usable by the operating system. *\li #ISC_R_NOPERM * The file could not be created because permission was denied * to some part of the file's path. *\li #ISC_R_IOERROR * Hardware error interacting with the filesystem. *\li #ISC_R_UNEXPECTED * Something totally unexpected happened. */ isc_result_t isc_file_remove(const char *filename); /*!< * \brief Remove the file named by 'filename'. */ isc_result_t isc_file_rename(const char *oldname, const char *newname); /*!< * \brief Rename the file 'oldname' to 'newname'. */ bool isc_file_exists(const char *pathname); /*!< * \brief Return #true if 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. */ bool isc_file_isabsolute(const char *filename); /*!< * \brief Return #true if the given file name is absolute. */ isc_result_t isc_file_isplainfile(const char *name); isc_result_t isc_file_isplainfilefd(int fd); /*!< * \brief Check that the file is a plain file * * Returns: *\li #ISC_R_SUCCESS * Success. The file is a plain file. *\li #ISC_R_INVALIDFILE * The path specified was not usable by the operating system. *\li #ISC_R_FILENOTFOUND * The file does not exist. This return code comes from * errno=ENOENT when stat returns -1. This code is mentioned * here, because in logconf.c, it is the one rcode that is * permitted in addition to ISC_R_SUCCESS. This is done since * the next call in logconf.c is to isc_stdio_open(), which * will create the file if it can. *\li other ISC_R_* errors translated from errno * These occur when stat returns -1 and an errno. */ isc_result_t isc_file_isdirectory(const char *name); /*!< * \brief Check that 'name' exists and is a directory. * * Returns: *\li #ISC_R_SUCCESS * Success, file is a directory. *\li #ISC_R_INVALIDFILE * File is not a directory. *\li #ISC_R_FILENOTFOUND * File does not exist. *\li other ISC_R_* errors translated from errno * These occur when stat returns -1 and an errno. */ bool isc_file_iscurrentdir(const char *filename); /*!< * \brief Return #true if the given file name is the current directory ("."). */ bool isc_file_ischdiridempotent(const char *filename); /*%< * Return #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); /*!< * \brief 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: *\li #ISC_R_SUCCESS *\li #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_result_t isc_file_truncate(const char *filename, isc_offset_t size); /*%< * Truncate/extend the file specified to 'size' bytes. */ isc_result_t isc_file_safecreate(const char *filename, FILE **fp); /*%< * Open 'filename' for writing, truncating if necessary. Ensure that * if it existed it was a normal file. If creating the file, ensure * that only the owner can read/write it. */ isc_result_t isc_file_splitpath(isc_mem_t *mctx, const char *path, char **dirname, char const **basename); /*%< * Split a path into dirname and basename. If 'path' contains no slash * (or, on windows, backslash), then '*dirname' is set to ".". * * Allocates memory for '*dirname', which can be freed with isc_mem_free(). * * Returns: * - ISC_R_SUCCESS on success * - ISC_R_INVALIDFILE if 'path' is empty or ends with '/' * - ISC_R_NOMEMORY if unable to allocate memory */ isc_result_t isc_file_getsize(const char *file, off_t *size); /*%< * Return the size of the file (stored in the parameter pointed * to by 'size') in bytes. * * Returns: * - ISC_R_SUCCESS on success */ isc_result_t isc_file_getsizefd(int fd, off_t *size); /*%< * Return the size of the file (stored in the parameter pointed * to by 'size') in bytes. * * Returns: * - ISC_R_SUCCESS on success */ void * isc_file_mmap(void *addr, size_t len, int prot, int flags, int fd, off_t offset); /*%< * Portable front-end to mmap(). If mmap() is not defined on this * platform, then we simulate it by calling malloc() and read(). * (In this event, the addr, prot, and flags parameters are ignored). */ int isc_file_munmap(void *addr, size_t len); /*%< * Portable front-end to munmap(). If munmap() is not defined on * this platform, then we simply free the memory. */ isc_result_t isc_file_sanitize(const char *dir, const char *base, const char *ext, char *path, size_t length); /*%< * Generate a sanitized filename, such as for MKEYS or NZF files. * * Historically, MKEYS and NZF files used SHA256 hashes of the view * name for the filename; this was to deal with the possibility of * forbidden characters such as "/" being in a view name, and to * avoid problems with case-insensitive file systems. * * Given a basename 'base' and an extension 'ext', this function checks * for the existence of file using the old-style name format in directory * 'dir'. If found, it returns the path to that file. If there is no * file already in place, a new pathname is generated; if the basename * contains any excluded characters, then a truncated SHA256 hash is * used, otherwise the basename is used. The path name is copied * into 'path', which must point to a buffer of at least 'length' * bytes. * * Requires: * - base != NULL * - path != NULL * * Returns: * - ISC_R_SUCCESS on success * - ISC_R_NOSPACE if the resulting path would be longer than 'length' */ bool isc_file_isdirwritable(const char *path); /*%< * Return true if the path is a directory and is writable */ ISC_LANG_ENDDECLS #endif /* ISC_FILE_H */
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