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Diffstat (limited to '')
-rw-r--r-- | lib/safe-read.h | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/lib/safe-read.h b/lib/safe-read.h new file mode 100644 index 0000000..d087447 --- /dev/null +++ b/lib/safe-read.h @@ -0,0 +1,47 @@ +/* An interface to read() that retries after interrupts. + Copyright (C) 2002, 2006, 2009-2023 Free Software Foundation, Inc. + + This file 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 file 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 program. If not, see <https://www.gnu.org/licenses/>. */ + +/* 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: Mac OS 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 <stddef.h> + +#ifdef __cplusplus +extern "C" { +#endif + + +#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 |