[iyunv@localhost test]# ll /test/
总用量 8
-rw-r--r--. 1 root root 43 8月 7 16:46 cat1
-rw-r--r--. 1 root root 19 8月 7 16:46 cat2
[iyunv@localhost test]# cat cat1
hi,everyone
now I will show how to use cat
[iyunv@localhost test]# cat -An cat1
1 hi,everyone$
2 now I will show how to use cat$
[iyunv@localhost test]# cat -nE cat1 cat2
1 hi,everyone$
2 now I will show how to use cat$
3 This is an example$
cat后面可以接多个文件,常用选项可以组合使用
tac cat的反向显示,按文本反向
tac - concatenate and print files in reverse
tac [OPTION]... [FILE]...
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[iyunv@localhost test]# tac cat1
now I will show how to use cat
hi,everyone
tac选项都不常用,因此不予介绍
rev 文件内容按行反向显示
rev - reverse lines of a file or files
rev [options] [file ...]
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[iyunv@localhost test]# rev cat1
enoyreve,ih
tac esu ot woh wohs lliw I won
rev无有价值可介绍选项
head
head - output the first part of files
head [OPTION]... [FILE]...
常用选项:
-c #:显示前多少个字节
-n #:显示前多少行,n可以省去
head file 默认显示文件前十行内容
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[iyunv@localhost test]# head -3 head
12345
67890
12
[iyunv@localhost test]# head -c 3 head
123[iyunv@localhost test]#
tail
tail - output the last part of files
tail [OPTION]... [FILE]...
常用选项:
-c #:显示后多少个字节
-n #:显示后多少行,n可以省去
-f :跟踪显示文件新追加的内容,常用日志监控
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[iyunv@localhost test]# tail -3 head
345
123
6
[iyunv@localhost test]# tail -c 5 head
23
6
[iyunv@localhost test]# tail -f /var/log/messages
Aug 7 17:15:04 localhost dhclient[9668]: DHCPDISCOVER on eno16777728 to 255.255.255.255 port 67 interval 11 (xid=0x7773726a)
Aug 7 17:15:05 localhost NetworkManager[916]: <warn> (eno16777728): DHCPv4 request timed out.
Aug 7 17:15:05 localhost NetworkManager[916]: <info> (eno16777728): DHCPv4 state changed unknown -> timeout
...
more 特点:翻屏至文件尾部后自动退出
more - file perusal filter for crt viewing
表达格式:more [options] file [...]
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[iyunv@localhost ~]# man /etc/init.d/functions
...
;; stop) s=$"Stopping
$prog (via systemctl): " ;; reload|try‐
reload) s=$"Reloading $prog configuration (via
systemctl): " ;; restart|try‐restart|con‐
drestart) s=$"Restarting $prog (via systemctl): "
;; esac
Manual page functions line 1 (press h for help or q to quit)
less
less - opposite of more
在less中可以使用之前在man里面的搜索功能,可以简单的认为less是more的加强版。