filemerge: split the logic for finding an external tool to its own function
This will be used by extdiff in an subsequent patch.
#!/bin/rc
# 9mail - Mercurial email wrapper for upas/marshal
fn usage {
echo >[1=2] usage: mercurial/9mail -f from to [cc]
exit usage
}
from=()
cc=()
to=()
switch($1){
case -f
from=$2
case *
usage
}
to=($3)
if(~ $#* 4)
cc=(-C $4)
upasname=$from
upas/marshal $cc $to