posixWriteCommand function

String posixWriteCommand(
  1. String path
)

The POSIX command that writes its stdin to file path: into a temporary file first, and onto path only once all of it has arrived — copied into the existing file (not moved over it), so its mode and owner stay.

Implementation

String posixWriteCommand(String path) =>
    't=\$(mktemp) || exit 1; cat > "\$t" && cat < "\$t" > ${posixQuote(path)}; '
    's=\$?; rm -f "\$t"; exit \$s';