X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=fd.c;h=86a1f10541f8ca64ffb659d2fc637ea61865e7ff;hp=a04232f84b3fd239249c866cb5a109551ad2b926;hb=e8d5da94efd6cbb0aa75f57290c76d9992ff8f47;hpb=f0e41e36c3f1a3a5bb6ff66d92d2814391d8f908 diff --git a/fd.c b/fd.c index a04232f8..86a1f105 100644 --- a/fd.c +++ b/fd.c @@ -1,8 +1,4 @@ -/* - * Copyright (C) 2006-2012 Andre Noll - * - * Licensed under the GPL v2. For licencing details see COPYING. - */ +/* Copyright (C) 2006 Andre Noll , see file COPYING. */ /** \file fd.c Helper functions for file descriptor handling. */ @@ -10,14 +6,36 @@ #include #include #include -#include -#include #include "para.h" #include "error.h" #include "string.h" #include "fd.h" +/** + * Change the name or location of a file. + * + * \param oldpath File to be moved. + * \param newpath Destination. + * + * This is just a simple wrapper for the rename(2) system call which returns a + * paraslash error code and prints an error message on failure. + * + * \return Standard. + * + * \sa rename(2). + */ +int xrename(const char *oldpath, const char *newpath) +{ + int ret = rename(oldpath, newpath); + + if (ret >= 0) + return 1; + ret = -ERRNO_TO_PARA_ERROR(errno); + PARA_ERROR_LOG("failed to rename %s -> %s\n", oldpath, newpath); + return ret; +} + /** * Write an array of buffers to a file descriptor. * @@ -146,6 +164,7 @@ __printf_2_3 int write_va_buffer(int fd, const char *fmt, ...) va_start(ap, fmt); ret = xvasprintf(&msg, fmt, ap); + va_end(ap); ret = write_all(fd, msg, ret); free(msg); return ret; @@ -162,13 +181,13 @@ __printf_2_3 int write_va_buffer(int fd, const char *fmt, ...) * * If \a rfds is not \p NULL and the (non-blocking) file descriptor \a fd is * not set in \a rfds, this function returns early without doing anything. - * Otherwise The function tries to read up to \a sz bytes from \a fd. As for - * xwrite(), EAGAIN is not considered an error condition. However, EOF - * is. + * Otherwise The function tries to read up to \a sz bytes from \a fd, where \a + * sz is the sum of the lengths of all vectors in \a iov. As for xwrite(), + * \p EAGAIN is not considered an error condition. However, \p EOF is. * * \return Zero or a negative error code. If the underlying call to readv(2) * returned zero (indicating an end of file condition) or failed for some - * reason other than \p EAGAIN, a negative return value is returned. + * reason other than \p EAGAIN, a negative error code is returned. * * In any case, \a num_bytes contains the number of bytes that have been * successfully read from \a fd (zero if the first readv() call failed with @@ -297,9 +316,9 @@ out: * * \param fn The file name. * - * \return Non-zero iff file exists. + * \return True iff file exists. */ -int file_exists(const char *fn) +bool file_exists(const char *fn) { struct stat statbuf; @@ -382,7 +401,7 @@ __must_check int mark_fd_nonblocking(int fd) * This wrapper for FD_SET() passes its first two arguments to \p FD_SET. Upon * return, \a max_fileno contains the maximum of the old_value and \a fd. * - * \sa para_select. + * \sa \ref para_select. */ void para_fd_set(int fd, fd_set *fds, int *max_fileno) { @@ -436,22 +455,20 @@ again: * 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. * \param map Result pointer. * * \return Standard. * * \sa mmap(2). */ -int para_mmap(size_t length, int prot, int flags, int fd, off_t offset, - void *map) +int para_mmap(size_t length, int prot, int flags, int fd, void *map) { void **m = map; errno = EINVAL; if (!length) goto err; - *m = mmap(NULL, length, prot, flags, fd, offset); + *m = mmap(NULL, length, prot, flags, fd, (off_t)0); if (*m != MAP_FAILED) return 1; err: @@ -526,6 +543,7 @@ static int para_opendir(const char *dirname, DIR **dir, int *cwd) { int ret; + *dir = NULL; if (cwd) { ret = para_open(".", O_RDONLY, 0); if (ret < 0) @@ -549,20 +567,6 @@ close_cwd: return ret; } -/** - * A wrapper for fchdir(). - * - * \param fd An open file descriptor. - * - * \return Standard. - */ -static int para_fchdir(int fd) -{ - if (fchdir(fd) < 0) - return -ERRNO_TO_PARA_ERROR(errno); - return 1; -} - /** * A wrapper for mkdir(2). * @@ -617,7 +621,23 @@ int mmap_full_file(const char *path, int open_mode, void **map, goto out; } *size = file_status.st_size; - ret = para_mmap(*size, mmap_prot, mmap_flags, fd, 0, map); + /* + * If the file is empty, *size is zero and mmap() would return EINVAL + * (Invalid argument). This error is common enough to spend an extra + * error code which explicitly states the problem. + */ + ret = -E_EMPTY; + if (*size == 0) + goto out; + /* + * If fd refers to a directory, mmap() returns ENODEV (No such device), + * at least on Linux. "Is a directory" seems to be more to the point. + */ + ret = -ERRNO_TO_PARA_ERROR(EISDIR); + if (S_ISDIR(file_status.st_mode)) + goto out; + + ret = para_mmap(*size, mmap_prot, mmap_flags, fd, map); out: if (ret < 0 || !fd_ptr) close(fd); @@ -634,7 +654,7 @@ out: * * \return Standard. * - * \sa munmap(2), mmap_full_file(). + * \sa munmap(2), \ref mmap_full_file(). */ int para_munmap(void *start, size_t length) { @@ -676,8 +696,6 @@ int write_ok(int fd) * * Common approach that opens /dev/null until it gets a file descriptor greater * than two. - * - * \sa okir's Black Hats Manual. */ void valid_fd_012(void) { @@ -711,7 +729,7 @@ int for_each_file_in_dir(const char *dirname, { DIR *dir; struct dirent *entry; - int cwd_fd, ret2, ret = para_opendir(dirname, &dir, &cwd_fd); + int cwd_fd, ret = para_opendir(dirname, &dir, &cwd_fd); if (ret < 0) return ret == -ERRNO_TO_PARA_ERROR(EACCES)? 1 : ret; @@ -747,9 +765,8 @@ int for_each_file_in_dir(const char *dirname, ret = 1; out: closedir(dir); - ret2 = para_fchdir(cwd_fd); - if (ret2 < 0 && ret >= 0) - ret = ret2; + if (fchdir(cwd_fd) < 0 && ret >= 0) + ret = -ERRNO_TO_PARA_ERROR(errno); close(cwd_fd); return ret; }