# Cuts every media size except one out of a CUPS PPD.
#
# macOS and Windows add this printer driverless: they never see this PPD, they
# see the IPP media-supported list cupsd derives from it. Trimming here is
# therefore the only way to make 4x6 the single choice a client can offer --
# there is no lpadmin option that restricts the media list.
#
# Regenerated from the driver's own PPD on every deploy, so a driver version
# bump carries its new PPD through this filter rather than being pinned to a
# fork.
#
#   awk -v keep=w288h432 -f trim-ppd-media.awk tspl-label.ppd
#
# The four families below are keyed by the PPD page-size keyword in field 2,
# which reads as "w288h432/4 x 6 in:" -- hence the split on "/".
/^\*(PageSize|PageRegion|ImageableArea|PaperDimension) / {
    split($2, f, "/")
    if (f[1] != keep) next
}

# Custom sizes would put "Manage Custom Sizes" back in the client's paper menu
# and let a job arrive at any dimension, which is the thing being prevented.
/^\*(CustomPageSize|ParamCustomPageSize|MaxMediaWidth|MaxMediaHeight)/ { next }

{ print }