/* io.c - light wrappers for POSIX i/o functions * Time-stamp: <2010-11-13 08:22:53 njk> * * (c) 2010 Nicholas J. Kain * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * - Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * - Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. */ #include #include /* returns -1 on error, >= 0 and equal to # chars read on success */ int safe_read(int fd, char *buf, int len) { int r, s = 0; while (s < len) { r = read(fd, buf + s, len - s); if (r == 0) break; if (r == -1) { if (errno == EINTR) continue; else return -1; } s += r; } return s; } /* returns -1 on error, >= 0 and equal to # chars written on success */ int safe_write(int fd, const char *buf, int len) { int r, s = 0; while (s < len) { r = write(fd, buf + s, len - s); if (r == -1) { if (errno == EINTR) continue; else return -1; } s += r; } return s; }