[[email protected] eric ~]# ls /etc > /tmp/list.out  (覆蓋輸出)   ls /etc >> /tmp/list.out  (追加輸出) 
 

[[email protected] eric ~]# cat /tmp/list.out 
abrt
acpi
adjtime
aliases
aliases.db

 tr - translate or delete characters
[[email protected] eric ~]# tr ‘a-z‘ ‘A-Z‘
abc
ABC
^C
[[email protected]

[[email protected] eric ~]# cat <<END(結束符)
> The first line
> The Second line
> END
The first line
The Second line
[[email protected] eric ~]# cat >> /tmp/myfile.txt <<EOF（End of Line）
> hello
> my dear
> EOF
[[email protected] eric ~]# cat /tmp/myfile.txt 
hello
my dear
[[email protected] eric ~]# 

管道：（從一端輸入東西，從另一端出來）命令也可以使用管道

命令1 | 命令2 | 命令3 |...前一個命令的輸出作為後一個命令的輸入

[[email protected] eric ~]# echo ‘hello‘ | tr ‘a-z‘ ‘A-Z‘
HELLO
[[email protected] eric ~]# echo ‘redhat‘|passwd --stdin hive
passwd: Unknown user name ‘hive‘.
[[email protected] eric ~]# echo ‘redhat‘|passwd --stdin cjy
Changing password for user cjy.
passwd: all authentication tokens updated successfully.
[[email protected] eric ~]# cut -d: f1 /etc/passwd |sort
cut: you must specify a list of bytes, characters, or fields
Try `cut --help‘ for more information.
[[email protected] eric ~]# cut -d: -f1 /etc/passwd |sort
abrt
adm
apache
avahi-autoipd
bin
cjy
daemon

[[email protected] eric ~]# wc -l /etc/passwd
36 /etc/passwd
[[email protected] eric ~]# wc -l /etc/passwd | cut -d‘ ‘ -f1
36
[[email protected] eric ~]# 

tee： - read from standard input and write to
standard output and files

linux筆記_day09