Shell递归程序设计-目录列表

UNIXShell脚本类似DOS的批处理命令，但比较起来UNIXShell的功能更强大，在某些方面，Shell甚至超过了一些高级语言。
下边的Shell脚本演示了如何用Shell脚本编写递归程序。

运行前先执行下述预备命令
lntree.sh/usr/bin/tree
lntree.sh/usr/bin/wtree
lntree.sh/usr/bin/dtree
rmtree.sh


#tree.sh

#DepthfirstDirectorylist
dtree(){
PWD=`pwd|sed's/\/\$//`
fordin$*
do
echo"${PWD}/$d"
[-d"$d"-a-x"$d"]%26%26{
cd"$d"
dtree*
cd..
PWD=`pwd|sed's/\/\$//`#restorePWD
}
done
}

#DepthfirstDirectorylist
wtree(){
PWD=`pwd|sed's/\/\$//`
fordin$*
do
echo${PWD}/$d
done
fordin$*
do
[-d"$d"-a-x"$d"]%26%26{
cd$d
wtree*
cd..
}
done
}

#Directorylist
tree(){
PWD=`pwd|sed's/\/\$//`
fordin$*
do
echo${PWD}/$d
done
}

#main
TREE=`basename$0`
if["$1"]
thenDIR="$1"
elseDIR="."
fi
ifcd$DIR
then$TREE*
elseecho"$0:Directory$1readfail."
fi

#(End)