gimme.sh

#! /bin/sh
# GIMME - "gimme' a file"
# Demonstrate rdist's ability to give me permission to access anything.
#
# gimme  [ []]
#        is the target file.
#        is the octal mode to which the file access permission
#               should be set.  Note that this may not be effective unless
#               either the SUID (4000) or SGID (2000) bits are also requested.
#        is the target directory for rdist to use if a hard
#               link is desired.  Note that the user must have permission
#               to create this directory, it must be on the same filesystem
#               as the target file, and the target file must not be a
#               directory.  This option is necessary to change the ownership
#               of the target if chown() of a symbolic link modifies the
#               link itself, and not the file it refers to.
#

dirname=gimme$$
deftemp=/tmp
defperm=6777

if [ $1x = x ]; then
        echo "Usage: $0  [ []]" >&2
        exit 1
fi

if [ $2x != x ]; then
        perm=$2
else
        perm=$defperm
fi

if [ $3x != x ]; then
        link="ln"
        temp=$3/$dirname
        target=$1
else
        link="ln -s"
        temp=$deftemp/$dirname
        case $1 in
        /*)
                target=$1
                ;;
        *)
                target=`pwd`/$1
                ;;
        esac
fi

trap "rm -fr $temp; exit 1"  1 2 15
umask 66
mkdir $temp; if [ $? != 0 ]; then
        exit 1
fi

set `whoami` $LOGNAME
user=$1
set daemon `groups`
while [ $# != 1 ]; do
        shift
done
group=$1

(
        echo "t$temp/something"
        echo "R0 $perm 1 0 $user $group "

        while [ ! -f $temp/rdist* ]; do
                sleep 1
        done

        set $temp/rdist*
        rm -f $1
        if $link $target $1 >&2; then
                echo "" | dd bs=3 conv=sync 2>/dev/null
                echo ""

                echo 0 > $temp/status
        else
                echo 1 > $temp/status
        fi

        exit
) | rdist -Server

dUmMy=`cat $temp/status`
rm -fr $temp
exit $status