/*
- * Copyright (C) 2006 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2006-2007 Andre Noll <maan@systemlinux.org>
*
- * 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 <sys/types.h>
+#include <dirent.h>
+#include <sys/mman.h>
#include <fcntl.h>
#include <sys/select.h>
+#include "para.h"
#include "error.h"
/**
* check whether a file exists
* \param n the highest-numbered descriptor in any of the two sets, plus 1
* \param readfds fds that should be checked for readability
* \param writefds fds that should be checked for writablility
- * \param timeout upper bound on the amount of time elapsed before select()
- * returns
+ * \param timeout_tv upper bound on the amount of time elapsed before select()
+ * returns
*
* \return The return value of the underlying select() call.
*
}
/**
- * paraslash's wrapper for fread(3)
+* paraslash's wrapper for fgets(3)
+* \param line pointer to the buffer to store the line
+* \param size the size of the buffer given by \a line
+* \param f the stream to read from
+*
+* \return Unlike the standard fgets() function, an integer value
+* is returned. On success, this function returns 1. On errors, -E_FGETS
+* is returned. A zero return value indicates an end of file condition.
+*/
+__must_check int para_fgets(char *line, int size, FILE *f)
+{
+again:
+ if (fgets(line, size, f))
+ return 1;
+ if (feof(f))
+ return 0;
+ if (!ferror(f))
+ return -E_FGETS;
+ if (errno != EINTR) {
+ PARA_ERROR_LOG("%s\n", strerror(errno));
+ return -E_FGETS;
+ }
+ clearerr(f);
+ goto again;
+}
+
+/**
+ * Paraslash's wrapper for mmap.
*
- * \param dest destination pointer
- * \param nbytes size of one element
- * \param nmemb number of elements to write
- * \param stream the input stream
+ * \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 negative on errors, zero on end of file, and the number of bytes
- * (not elements) read on success.
+ * \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.
*
- * \sa fread(3)
+ * The mode parameter must be specified when O_CREAT is in the flags, and is ignored
+ * otherwise.
+ *
+ * \return Positive on success, negative on errors.
+ *
+ * \sa open(2).
*/
-__must_check int para_fread(void *dest, size_t nbytes, size_t nmemb, FILE *stream)
+int para_open(const char *path, int flags, mode_t mode)
{
- size_t res = fread(dest, nbytes, nmemb, stream);
- if (res == nmemb)
- return nbytes * nmemb;
- if (feof(stream))
- return 0;
- return -E_FREAD;
+ 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;
}
projects / paraslash.git / blobdiff