% which touch
/usr/bin/touch

##</code><code>##

`echo "#!/usr/bin/env touch $file" > tmp.sh`;

##</code><code>##

`echo "#!\$(which touch) $file" > tmp.sh`;

##</code><code>##

`echo "#!/usr/bin/env perl -e 'system \"\$(which touch) $file\"'" > tmp.pl`;
system './tmp.pl';