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10.1335 write

POSIX specification:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/write.html

Gnulib module: write, nonblocking, sigpipe

Portability problems fixed by Gnulib module write:

• This function is declared in a different header file (namely, <io.h>) on some platforms: mingw, MSVC 14.
• This function crashes when invoked with invalid arguments on some platforms: MSVC 14.

Portability problems fixed by Gnulib module stdio, together with module nonblocking:

• When writing to a non-blocking pipe whose buffer is full, this function fails with errno being set to ENOSPC instead of EAGAIN on some platforms: mingw, MSVC 14.
• When writing to a non-blocking pipe on which no reader is currently waiting an amount of bytes that exceeds the pipe buffer’s size, then—even if the pipe’s buffer is empty—this function fails, instead of performing a partial write into the pipe buffer, on some platforms: mingw, MSVC 14.

Portability problems fixed by Gnulib module stdio, together with module sigpipe:

• When writing to a pipe with no readers, this function fails with error EINVAL, instead of obeying the current SIGPIPE handler, on some platforms: mingw, MSVC 14.

Portability problems not fixed by Gnulib:

• This function may fail with error EINTR, even in programs that don’t install any signal handlers, on some platforms: macOS 14.

For handling EINTR, Gnulib provides a module ‘safe-write’ with a function safe_write.