X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=fd.c;h=398bf2ce818345a6cc3d98648953fa05096a8b48;hp=637884b4b895a9279c5c928ea4028dbddb1a74c7;hb=a8509af9116e9a045ace70ff312e40569c5ace16;hpb=dc3bbfa529d9eb9151fdc4119983e8bdf23f751d diff --git a/fd.c b/fd.c index 637884b4..398bf2ce 100644 --- a/fd.c +++ b/fd.c @@ -1,28 +1,18 @@ /* * Copyright (C) 2006-2007 Andre Noll * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA. + * Licensed under the GPL v2. For licencing details see COPYING. */ /** \file fd.c helper functions for file descriptor handling */ -#include "para.h" - +#include +#include +#include #include #include +#include "para.h" #include "error.h" /** * check whether a file exists @@ -118,28 +108,6 @@ void para_fd_set(int fd, fd_set *fds, int *max_fileno) *max_fileno = PARA_MAX(*max_fileno, fd); } -/** - * paraslash's wrapper for fread(3) - * - * \param dest destination pointer - * \param nbytes size of one element - * \param nmemb number of elements to write - * \param stream the input stream - * - * \return negative on errors, zero on end of file, and the number of bytes - * (not elements) read on success. - * - * \sa fread(3) - */ -__must_check int para_fread(void *dest, size_t nbytes, size_t nmemb, FILE *stream) -{ - size_t res = fread(dest, nbytes, nmemb, stream); - if (res == nmemb) - return nbytes * nmemb; - if (feof(stream)) - return 0; - return -E_FREAD; -} /** * paraslash's wrapper for fgets(3) * \param line pointer to the buffer to store the line @@ -168,18 +136,152 @@ again: } /** - * paralash's wrapper for fseek(3) + * Paraslash's wrapper for mmap. * - * \param stream stream to seek - * \param offset added to the position specified by whence - * \param whence \p SEEK_SET, \p SEEK_CUR, or \p SEEK_END + * \param length number of bytes to mmap + * \param prot either PROT_NONE or the bitwise OR of one or more of + * PROT_EXEC PROT_READ PROT_WRITE + * \param flags exactly one of MAP_SHARED and MAP_PRIVATE + * \param fd the file to mmap from + * \param offset mmap start * - * \return positive on success, -E_FSEEK on errors. + * \return This function either returns a valid pointer to the mapped area + * or calls exit() on errors. + */ +void *para_mmap(size_t length, int prot, int flags, int fd, off_t offset) +{ + void *ret = mmap(NULL, length, prot, flags, fd, offset); + if (ret != MAP_FAILED) + return ret; + PARA_EMERG_LOG("mmap failed: %s\n", strerror(errno)); + PARA_EMERG_LOG("length: %zu, flags: %d, fd: %d, offset: %zu\n", + length, flags, fd, (size_t)offset); + exit(EXIT_FAILURE); +} + +/** + * Wrapper for the open(2) system call. + * + * \param path The filename. + * \param flags The usual open(2) flags. + * \param mode Specifies the permissions to use. + * + * The mode parameter must be specified when O_CREAT is in the flags, and is ignored + * otherwise. * - * \sa fseek(3) + * \return Positive on success, negative on errors. + * + * \sa open(2). */ -int para_fseek(FILE *stream, long offset, int whence) +int para_open(const char *path, int flags, mode_t mode) { - int ret = fseek(stream, offset, whence); - return ret < 0? -E_FSEEK : 1; + int ret = open(path, flags, mode); + + if (ret >= 0) + return ret; + switch (errno) { + case EEXIST: + ret = -E_EXIST; + break; + case EISDIR: + ret = -E_ISDIR; + break; + case ENOENT: + ret = -E_NOENT; + break; + case EPERM: + ret = -E_OPEN_PERM; + break; + }; + PARA_ERROR_LOG("failed to open %s: %s\n", path, strerror(errno)); + return ret; +} + +/** + * Save the cwd and open a given directory. + * + * \param dirname Path to the directory to open. + * \param dir Result pointer. + * \param cwd File descriptor of the current working directory. + * + * \return Positive on success, negative on errors. + * + * Opening the current directory (".") and calling fchdir() to return is + * usually faster and more reliable than saving cwd in some buffer and calling + * chdir() afterwards. + * + * If \a cwd is not \p NULL "." is opened and the resulting file descriptor is + * stored in \a cwd. If the function returns success, and \a cwd is not \p + * NULL, the caller must close this file descriptor (probably after calling + * fchdir(*cwd)). + * + * On errors, the function undos everything, so the caller needs neither close + * any files, nor change back to the original working directory. + * + * \sa getcwd(3). + * + */ +int para_opendir(const char *dirname, DIR **dir, int *cwd) +{ + int ret; + + if (cwd) { + ret = para_open(".", O_RDONLY, 0); + if (ret < 0) + return ret; + *cwd = ret; + } + ret = -E_CHDIR; + if (chdir(dirname) < 0) + goto close_cwd; + ret = -E_OPENDIR; + *dir = opendir("."); + if (!*dir) + goto change_to_orig_dir; + return 1; +/* Ignore return value of fchdir() and close(). We're busted anyway. */ +change_to_orig_dir: + if (cwd) + fchdir(*cwd); +close_cwd: + if (cwd) + close(*cwd); + return ret; +} + +/** + * A wrapper for fchdir(). + * + * \param fd An open file descriptor + * + * \return Positive on success, negative on errors. + */ +int para_fchdir(int fd) +{ + if (fchdir(fd) < 0) + return -E_FCHDIR; + return 1; +} + +/** + * A wrapper for mkdir(2). + * + * \param path Name of the directory to create. + * \param mode The permissions to use. + * + * \return positive on success, negative on errors. + */ +int para_mkdir(const char *path, mode_t mode) +{ + if (!mkdir(path, mode)) + return 1; + if (errno == EEXIST) + return -E_EXIST; + if (errno == ENOSPC) + return -E_NOSPC; + if (errno == ENOTDIR) + return -E_NOTDIR; + if (errno == EPERM) + return -E_MKDIR_PERM; + return -E_MKDIR; }