输出文件内容到终端

输出一个文件：

cat file1

输出多个文件：

cat file1 file2

输出文件内容，显示行号：

cat -n song.txt

1  "Heal The World"
2  There's A Place In
3  Your Heart
4  And I Know That It Is Love
5  And This Place Could

行尾和空行显示 $:

cat -e test

hello everyone, how do you do?$
$
Hey, am fine.$
How's your training going on?$
$

新建文件：

新建空文件：

cat /dev/null > file

将文件复制到新文件：

cat file1 > file2

将文件复制添加到文件末尾：

cat file1 >> file2

将多个文件合并到一个文件：

cat file1 file2 file3 > file_new
cat file* > file_new