On 05/10/2010 02:19 PM, Eric Blake wrote:
Some shells warn about missing programs before redirection; the idiomatic way to silence them is to run the program check inside a subshell, with the redirections outside the subshell.
+++ b/cfg.mk @@ -252,7 +252,7 @@ sc_prohibit_trailing_blank_lines: preprocessor_exempt = (remote_(driver|protocol)\.h)$$ # Enforce recommended preprocessor indentation style. sc_preprocessor_indentation: - @if (cppi --version >/dev/null 2>&1); then \ + @if (cppi --version) >/dev/null 2>&1; then \
Offlist, Jim reminded me that cfg.mk is only for developers with nice environments, where we shouldn't need the subshell at all...
$(VC_LIST_EXCEPT) | grep '\.[ch]$$' \ | grep -vE '$(preprocessor_exempt)' | xargs cppi -a -c \ || { echo '$(ME): incorrect preprocessor indentation' 1>&2; \ diff --git a/src/Makefile.am b/src/Makefile.am index fe33cea..1542ab1 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -169,7 +169,7 @@ EXTRA_DIST += remote/remote_protocol.x remote/rpcgen_fix.pl # * remove white space at end of buffer .PHONY: remote_protocol-structs remote_protocol-structs: - $(AM_V_GEN)if pdwtags --help > /dev/null 2>&1; then \ + $(AM_V_GEN)if (pdwtags --help) > /dev/null 2>&1; then \
But here, not only is Solaris /bin/sh noisy (which we are starting to care less about these days, because it is so crufty), but so is FreeBSD 8.0 /bin/sh, which is a lot newer. And since it appears as part of the user's Makefile, rather than development-specific, it should be silent. Given that analysis, Jim gave the off-list ACK. So I've kept the second hunk as-is, modified the first to drop the subshell altogether, and pushed. -- Eric Blake eblake@redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org