Support non-blocking pipe I/O in write() on native Windows. * lib/unistd.in.h (write): Enable replacement also if GNULIB_UNISTD_H_NONBLOCKING is 1. * lib/write.c: Enable replacement also if GNULIB_NONBLOCKING. (rpl_write): When failing to write on a non-blocking pipe, change errno from ENOSPC to EAGAIN. * lib/stdio.in.h (fprintf, fputc, fputs, fwrite, printf, putc, putchar, puts, vfprintf, vprintf): Enable replacement also if GNULIB_STDIO_H_NONBLOCKING is 1. * lib/stdio-write.c: Enable replacements also if GNULIB_NONBLOCKING. (CLEAR_ERRNO, HANDLE_ENOSPC): New macros. (CLEAR_LastError, HANDLE_ERROR_NO_DATA): New macros, extracted from CALL_WITH_SIGPIPE_EMULATION. (CALL_WITH_SIGPIPE_EMULATION): Use them. * m4/nonblocking.m4: New file. * m4/write.m4 (gl_FUNC_WRITE): Enable REPLACE_WRITE also if required for non-blocking I/O support. * m4/unistd_h.m4 (gl_UNISTD_H_DEFAULTS): Initialize GNULIB_UNISTD_H_NONBLOCKING. * m4/stdio_h.m4 (gl_STDIO_H): Enable REPLACE_STDIO_WRITE_FUNCS also if required for non-blocking I/O support. (gl_STDIO_H_DEFAULTS): Initialize GNULIB_STDIO_H_NONBLOCKING. * modules/nonblocking (Files): Add m4/nonblocking.m4, lib/stdio-write.c, m4/asm-underscore.m4. (Depends-on): Add stdio, unistd. (configure.ac): Invoke gl_NONBLOCKING_IO. Define GNULIB_NONBLOCKING. Set GNULIB_STDIO_H_NONBLOCKING, GNULIB_UNISTD_H_NONBLOCKING. * modules/unistd (Makefile.am): Substitute GNULIB_UNISTD_H_NONBLOCKING. * modules/stdio (Makefile.am): Substitute GNULIB_STDIO_H_NONBLOCKING. * doc/posix-functions/fprintf.texi: Mention 'nonblocking' module and problem with non-blocking pipes. * doc/posix-functions/fputc.texi: Likewise. * doc/posix-functions/fputs.texi: Likewise. * doc/posix-functions/fwrite.texi: Likewise. * doc/posix-functions/printf.texi: Likewise. * doc/posix-functions/putc.texi: Likewise. * doc/posix-functions/putchar.texi: Likewise. * doc/posix-functions/puts.texi: Likewise. * doc/posix-functions/vfprintf.texi: Likewise. * doc/posix-functions/vprintf.texi: Likewise. * doc/posix-functions/write.texi: Likewise.

#include <stdio.h>
int close_stream (FILE *stream);