shell [ here 文档的用法初步 ]

#!/bin/bash

cat << !HER!
hello
this is a here
document

!HER!

62.txt

this is line 1
this is line 2
this is line 3
this is line 4

62.sh

#!/bin/bash

ed 62.txt << !HER!
3
d
.,\$s/is/was/
w
q
!HER!

exit 0