diff options
Diffstat (limited to 'lib/read.c')
-rw-r--r-- | lib/read.c | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/lib/read.c b/lib/read.c new file mode 100644 index 0000000..a0bdf06 --- /dev/null +++ b/lib/read.c @@ -0,0 +1,95 @@ +/* POSIX compatible read() function. + Copyright (C) 2008-2023 Free Software Foundation, Inc. + Written by Bruno Haible <bruno@clisp.org>, 2011. + + 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/>. */ + +#include <config.h> + +/* Specification. */ +#include <unistd.h> + +#if defined _WIN32 && ! defined __CYGWIN__ + +# include <errno.h> +# include <io.h> + +# define WIN32_LEAN_AND_MEAN /* avoid including junk */ +# include <windows.h> + +# if HAVE_MSVC_INVALID_PARAMETER_HANDLER +# include "msvc-inval.h" +# endif +# if GNULIB_MSVC_NOTHROW +# include "msvc-nothrow.h" +# else +# include <io.h> +# endif + +/* Don't assume that UNICODE is not defined. */ +# undef GetNamedPipeHandleState +# define GetNamedPipeHandleState GetNamedPipeHandleStateA + +# undef read + +# if HAVE_MSVC_INVALID_PARAMETER_HANDLER +static ssize_t +read_nothrow (int fd, void *buf, size_t count) +{ + ssize_t result; + + TRY_MSVC_INVAL + { + result = _read (fd, buf, count); + } + CATCH_MSVC_INVAL + { + result = -1; + errno = EBADF; + } + DONE_MSVC_INVAL; + + return result; +} +# else +# define read_nothrow _read +# endif + +ssize_t +rpl_read (int fd, void *buf, size_t count) +{ + ssize_t ret = read_nothrow (fd, buf, count); + +# if GNULIB_NONBLOCKING + if (ret < 0 + && GetLastError () == ERROR_NO_DATA) + { + HANDLE h = (HANDLE) _get_osfhandle (fd); + if (GetFileType (h) == FILE_TYPE_PIPE) + { + /* h is a pipe or socket. */ + DWORD state; + if (GetNamedPipeHandleState (h, &state, NULL, NULL, NULL, NULL, 0) + && (state & PIPE_NOWAIT) != 0) + /* h is a pipe in non-blocking mode. + Change errno from EINVAL to EAGAIN. */ + errno = EAGAIN; + } + } +# endif + + return ret; +} + +#endif |