X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;ds=sidebyside;f=lib%2Fsafe-read.h;h=7174de7e125945c03de0754c88f13628195b8bb4;hb=cbfeef01ad4ed6d3f68c3deb3c05d3b8102c84ff;hp=be957a6696f3fb5d9d7aee857459d45c94699d18;hpb=c965104eef36ec67974dc365b38a32ad21010853;p=gnulib.git diff --git a/lib/safe-read.h b/lib/safe-read.h index be957a669..7174de7e1 100644 --- a/lib/safe-read.h +++ b/lib/safe-read.h @@ -1,10 +1,47 @@ -#ifndef PARAMS -# if defined PROTOTYPES || (defined __STDC__ && __STDC__) -# define PARAMS(Args) Args -# else -# define PARAMS(Args) () -# endif +/* An interface to read() that retries after interrupts. + Copyright (C) 2002, 2006, 2009-2011 Free Software Foundation, Inc. + + 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 3 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, see . */ + +/* Some system calls may be interrupted and fail with errno = EINTR in the + following situations: + - The process is stopped and restarted (signal SIGSTOP and SIGCONT, user + types Ctrl-Z) on some platforms: MacOS X. + - The process receives a signal for which a signal handler was installed + with sigaction() with an sa_flags field that does not contain + SA_RESTART. + - The process receives a signal for which a signal handler was installed + with signal() and for which no call to siginterrupt(sig,0) was done, + on some platforms: AIX, HP-UX, IRIX, OSF/1, Solaris. + + This module provides a wrapper around read() that handles EINTR. */ + +#include + +#ifdef __cplusplus +extern "C" { #endif -ssize_t -safe_read PARAMS ((int desc, char *ptr, size_t len)); + +#define SAFE_READ_ERROR ((size_t) -1) + +/* Read up to COUNT bytes at BUF from descriptor FD, retrying if interrupted. + Return the actual number of bytes read, zero for EOF, or SAFE_READ_ERROR + upon error. */ +extern size_t safe_read (int fd, void *buf, size_t count); + + +#ifdef __cplusplus +} +#endif