在Linux操作系统下，如何以类似格式的结构列出目录的内容？您需要使用名为tree的命令。它将以树状格式列出目录的内容。这是一个递归目录列表程序，可生成深度缩进的文件列表。给定目录参数后，树将依次列出在给定目录中找到的所有文件和/或者目录。 完成列出所有找到的文件/目录后，tree返回列出的文件和/或者目录的总数。

在Linux上安装tree命令

缺省情况下，未安装tree命令。
执行以下命令，使用yum命令在RHEL/CentOS/Fedora Linux上安装相同的命令：

# yum install tree

如果您使用的是Debian/Mint/Ubuntu Linux，请执行以下apt-get命令/apt命令以安装tree命令：

$ sudo apt-get install tree

如果您使用的是Apple OS X/macOS，请输入brew命令：

brew install tree

Linux查看目录树结构的语法

语法为：

tree
tree /path/to/directory
tree [options]
tree [options] /path/to/directory

以树状格式列出/etc的内容：

tree /etc

应该传递-a选项以查看所有文件。
默认情况下，tree不打印隐藏文件(以点开头的文件)。
树决不会打印文件系统构造。

.(当前目录)和..(上一个目录)。

tree -a

要仅列出目录，请运行：

tree -d

使用内置颜色默认值，传递-C选项以查看彩色输出：

tree -C

这是tree程序支持的所有选项的列表：

------- Listing options ------
  -a            All files are listed.
  -d            List directories only.
  -l            Follow symbolic links like directories.
  -f            Print the full path prefix for each file.
  -x            Stay on current filesystem only.
  -L level      Descend only level directories deep.
  -R            Rerun tree when max dir level reached.
  -P pattern    List only those files that match the pattern given.
  -I pattern    Do not list files that match the given pattern.
  --ignore-case Ignore case when pattern matching.
  --matchdirs   Include directory names in -P pattern matching.
  --noreport    Turn off file/directory count at end of tree listing.
  --charset X   Use charset X for terminal/HTML and indentation line output.
  --filelimit # Do not descend dirs with more than # files in them.
  --timefmt <f> Print and format time according to the format <f>.
  -o filename   Output to file instead of stdout.
  -------- File options --------
  -q            Print non-printable characters as '?'.
  -N            Print non-printable characters as is.
  -Q            Quote filenames with double quotes.
  -p            Print the protections for each file.
  -u            Displays file owner or UID number.
  -g            Displays file group owner or GID number.
  -s            Print the size in bytes of each file.
  -h            Print the size in a more human readable way.
  --si          Like -h, but use in SI units (powers of 1000).
  -D            Print the date of last modification or (-c) status change.
  -F            Appends '/', '=', '*', '@', '|' or '>' as per ls -F.
  --inodes      Print inode number of each file.
  --device      Print device ID number to which each file belongs.
  ------- Sorting options ------
  -v            Sort files alphanumerically by version.
  -t            Sort files by last modification time.
  -c            Sort files by last status change time.
  -U            Leave files unsorted.
  -r            Reverse the order of the sort.
  --dirsfirst   List directories before files (-U disables).
  --sort X      Select sort: name,version,size,mtime,ctime.
  ------- Graphics options -----
  -i            Don't print indentation lines.
  -A            Print ANSI lines graphic indentation lines.
  -S            Print with CP437 (console) graphics indentation lines.
  -n            Turn colorization off always (-C overrides).
  -C            Turn colorization on always.
  ------- XML/HTML/JSON options ------
  -X            Prints out an XML representation of the tree.
  -J            Prints out an JSON representation of the tree.
  -H baseHREF   Prints out HTML format with baseHREF as top directory.
  -T string     Replace the default HTML title and H1 header with string.
  --nolinks     Turn off hyperlinks in HTML output.
  ---- Miscellaneous options ---
  --version     Print version and exit.
  --help        Print usage and this help message and exit.
  --            Options processing terminator.