source: downloads/tcl8.5.2/unix/installManPage @ 45

#!/bin/sh

ZIP=:
while true; do
    case $1 in
        -s | --symlinks  )      S="-s ";;
        -z | --compress  )    ZIP=$2;  shift ;;
        -e | --extension )      Z=$2;  shift ;;
        -s | --suffix    ) SUFFIX=$2;  shift ;;
        *)  break ;;
    esac
    shift
done
if test "$#" != 2; then
    echo "Usage: installManPages <options> file dir"
    exit 1
fi

MANPAGE=$1
DIR=$2
test -z "$S" && S="$DIR/"

# A sed script to parse the alternative names out of a man page.
#
# Backslashes are trippled in the sed script, because it is in
# backticks which doesn't pass backslashes literally.
#
NAMES=`sed -n '
#                               Look for a line, that starts with .SH NAME
#                               optionally allow NAME to be surrounded
#                               by quotes.
    /^\.SH NAME/{
#                               Read next line
        n
#                               Remove all commas ...
        s/,//g
#                               ... and backslash-escaped spaces.
        s/\\\ //g
#                               Delete from \- to the end of line
        s/ \\\-.*//
#                               print the result and exit
        p;q
    }' $MANPAGE`

case $MANPAGE in
    *.1) SECTION=1 ;;
    *.3) SECTION=3 ;;
    *.n) SECTION=n ;;
esac

SRCDIR=`dirname $MANPAGE`

FIRST=""
for f in $NAMES; do
    f=$f.$SECTION$SUFFIX
    if test -z "$FIRST" ; then
        FIRST=$f
        rm -f $DIR/$FIRST $DIR/$FIRST.*
        sed -e "/man\.macros/r $SRCDIR/man.macros" -e "/man\.macros/d" \
            $MANPAGE > $DIR/$FIRST
        chmod 444 $DIR/$FIRST
        $ZIP $DIR/$FIRST
    else
        rm -f $DIR/$f $DIR/$f.*
        ln $S$FIRST$Z $DIR/$f$Z
    fi
done