/* * pread function * * Copyright 1996 Alexandre Julliard * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA */ #include "config.h" #include "wine/port.h" #include <errno.h> #include <stdio.h> #ifdef HAVE_UNISTD_H # include <unistd.h> #endif #ifdef HAVE_IO_H # include <io.h> #endif /* FIXME: this is not thread-safe */ #ifndef HAVE_PREAD ssize_t pread( int fd, void *buf, size_t count, off_t offset ) { ssize_t ret; off_t old_pos; if ((old_pos = lseek( fd, 0, SEEK_CUR )) == -1) return -1; if (lseek( fd, offset, SEEK_SET ) == -1) return -1; if ((ret = read( fd, buf, count )) == -1) { int err = errno; /* save errno */ lseek( fd, old_pos, SEEK_SET ); errno = err; return -1; } if (lseek( fd, old_pos, SEEK_SET ) == -1) return -1; return ret; } #endif /* HAVE_PREAD */