#/etc/autofs.master
/home/.5a       /etc/auto.home5a
/home/.5b       /etc/auto.home5b

#cat  /etc/auto.home5b
#! /bin/sh

key="$1"

suffix=${key#?}
prefix=${key%$suffix}

echo "-rw,nosuid,nodev,nfsvers=3,rsize=32768,wsize=32768,intr,tcp home5b-505.nfs.xs4all.net:/vol/home5b/home2/home/$prefix/$key"
###############################
# ps axuw |grep auto
root      4253  0.0  0.0  16228   752 ?        Ss   01:30   0:00 /usr/sbin/automount --pid-file=/var/run/autofs/_home_.5b.pid --timeout=300 /home/.5b program /etc/auto.home5b