#!/bin/sh
# getmac - get a *roff macro definition
# Usage: getmac -package macro

case $1 in
 -mm) file="/usr/lib/macros/mmt";;
 -ms) file="/usr/lib/tmac/tmac.s";;
 -me) file="/usr/lib/tmac/tmac.e";;
 -man) file="/usr/lib/tmac/tmac.an";;
 *) echo "Usage: getmac -package macro" 1>&2; exit 1;;
esac
mac=$2

# Have sed search text without printing until it finds a line starting with
# ".de", optional spaces, and the macro name (passed in from the $mac shell
# variable, which is outside the quotes).  From there until the closing
# "..", do the commands inside the braces:
# - the first command happens at the .de line; it prints a three-line *roff
#   comment with the macro package and filename (which the shell inserts
#   because they're outside quotes).
# - print all lines of the macro definition
# - make sed quit after the closing ".." is printed.  This won't show
#   any subsequent re-definition of the macro in the same file.  But
#   that isn't likely to happen, so this saves time because sed doesn't
#   have to waste time reading the rest of the macro file.
sed -n '
/^\.de *'$mac'/,/^\.\.$/ {
	/^\.de/i\
.\\"\
.\\" The following definition of '$mac' was found in '$file':\
.\\"
	p
	/^\.\.$/q
}' $file