Linux Quote

反斜杠
你可以将一个 \ 放到一个字符的前面起转义作用。

$ echo hello world!
hello world!
$ rm file\ with\ spaces.txt
$ echo This could be \
a very \
long line.
This could be a very long line.

单引号

$ echo a       b
a b
$ echo a\ \ \ \ \ \ \ b
a       b
$ echo 'a       b'
a       b
$ echo 'can-quote*any $meta#chars'
can-quote*any $meta#chars

双引号

$ echo 'Is your home directory $HOME?'
Is your home directory $HOME?
$ echo "Is your home directory $HOME?"
Is your home directory /home/mitnk?
$ echo "Current path is `pwd`"
Current path is /home/mitnk/projects

点号（`）

$ echo "Current path is `pwd`"
Current path is /home/mitnk/projects
$ echo `pwd`
/home/mitnk/projects
$ echo "Today is `date`"
Today is Wed Mar  2 00:51:50 CST 2011

在文件名中使用引号

1. cp /dev/null 'a file with spaces in the name'
2. mv a\ file a_file
3. mv a 'a?'
(use "?" and "*" in a filename is playing with fire.)

在引号中使用引号

1. echo "Don't do that"
2. echo 'The quote of the day is: "TGIF"'

看看你引号是不是用错了
当你不确定引号是不是用对时
可以在命令的前面加上echo试试
（虽然echo不是总合适）
在引号中使用引用相同的引号

1. echo "The word is \"Friday\""
2. echo 'Don\'t quote me'
3. echo 'a'b'c'
3.1. echo 'a'$HOME'c'

HERE IS documents

% sort > file << EndOfSort
zygote
abacus
EndOfSort

详细解説见： www.grymoire.com