Re: pkg_alternatives does not allow for comments in ALTERNATIVES file (and the fix for this)

[Robert Elz <kre%munnari.OZ.AU@localhost>]

    Date:        Thu, 19 Sep 2019 11:51:13 +0200
    From:        "Aleksej Lebedev" <root%zta.lk@localhost>
    Message-ID:  <71ea2e59-0e04-4b08-9287-278127d36209%www.fastmail.com@localhost>

Assuming this is something that is wanted (

	not my call)...

  | $ git diff .
  | diff --git a/pkgtools/pkg_alternatives/files/pkg_alternatives.sh b/pkgtools/pkg_alternatives/files/pkg_alternatives.sh
  | index 56a19b10524..3d794ee83d2 100644
  | --- a/pkgtools/pkg_alternatives/files/pkg_alternatives.sh
  | +++ b/pkgtools/pkg_alternatives/files/pkg_alternatives.sh
  | @@ -56,7 +56,7 @@ action_auto_package() {
  |      validate_package ${1}
  |      pkg=${PKG_DBDIR}/${1}*/+ALTERNATIVES
  |  
  | -    set -- $(cat ${pkg} | sed -e 's# #__dE/lImIt/Er__#g')
  | +    set -- $(grep -v -e '^[[:space:]]*#' ${pkg} | sed -e 's# #__dE/lImIt/Er__#g')
  |      while [ ${#} -gt 0 ]; do
  |          action_auto_wrapper ${1%%__dE/lImIt/Er__*}
  |          shift

grep | sed is kind of insane unless there's a very good reason for it.

(So is the current "cat file | sed" where "sed < file" would do as well,
except that here "file" contains a glob expression, which doesn't work
(portably) with redirections, so the current method is correct.)

It seems possible that the glob might expand into more than one file,
in which case the grep | sed would end up having grep put file names
in its output
	file1:line without a comment
	file1:another
	file2:line without comment
or similar, which doesn't seem ideal, so as a mininum you'd need -h
as an extra option to avoid that (and I have no idea how portable that
option is).

So, keep the cat, and let sed do the work instead of adding grep.

Something like (untested)

	set -- $( cat $pkg |
			sed -e '/^[[:space:]]*#/d' \
			    -e 's# #__dE/lImIt/Er__#g'  )

kre