当前位置:网站首页>redirect action
redirect action
2022-08-09 20:15:00 【Sun Xiaoshen】
一、将输出重定向到文件或程序.
用法 | 说明 |
---|---|
> file | 重定向标准输出(stdout);以覆盖文件 |
>> file | 重定向标准输出(stdout);To attached to the file |
2> file | 重定向标准输入(stderr);以覆盖文件 |
2> /dev/null | 将标准输入(stderr)错误消息重定向到/dev/null,Thus will be discarded him |
&> file 或 > file 2>&1 | 重定向标准输出(stdout)和标准输入(stderr)To cover the same file |
&>> file 或 >> file 2>&1 | 重定向标准输出(stdout)和标准输入(stderr)In additional to the same file |
注意:Redirect file sequence of operation is very important
> file 2>&1
将标准输出重定向到file,Then the standard error as a standard output to the same place(file).
2>&1 > file
In contrast to the above,The standard error is redirected to standard output the default location(终端窗口,因此没有任何更改),Only will then standard output redirectionfile.
示例
1、使用dateCommand to view the timestamp saved to/tmp/dateback中,供日后参考.
[[email protected] ~]$ date > /tmp/dateback
[[email protected] ~]$ cat /tmp/dateback
Wed 3 Aug 19:55:43 CST 2022
2、To a log file finally100Line to another file.
[[email protected] ~]$ sudo tail -n 100 /var/log/messages > /tmp/end-100
[[email protected] ~]$ wc -l /tmp/end-100
100 /tmp/end-100
3、将4A file link as1个文件.
[[email protected] log]$ sudo cat lastlog maillog tallylog > /tmp/old-log
4、Hide home directory of the file name and file name list to a file.
[[email protected] ~]$ ls -a > /tmp/my-file
5、Attach the output to the existing file.
[[email protected] ~]$ echo "new line of information" >> /tmp/many-lines
[[email protected] log]$ sudo diff lastlog tallylog >> /tmp/tracking-mode
6、When checking in on ordinary command output terminal,The error is redirected to the file.
[[email protected] ~]$ find /etc -name passwd 2> /tmp/errors
/etc/pam.d/passwd
/etc/passwd
[[email protected] ~]$ cat /tmp/errors
find: ‘/etc/lvm/archive’: Permission denied
find: ‘/etc/lvm/backup’: Permission denied
find: ‘/etc/lvm/cache’: Permission denied
find: ‘/etc/pki/rsyslog’: Permission denied
find: ‘/etc/pki/pesign’: Permission denied
find: ‘/etc/ssh/sshd_config.d’: Permission denied
find: ‘/etc/grub.d’: Permission denied
find: ‘/etc/sssd’: Permission denied
find: ‘/etc/polkit-1/rules.d’: Permission denied
find: ‘/etc/polkit-1/localauthority’: Permission denied
find: ‘/etc/cups/ssl’: Permission denied
find: ‘/etc/cni/net.d’: Permission denied
find: ‘/etc/nftables’: Permission denied
find: ‘/etc/audit’: Permission denied
find: ‘/etc/sudoers.d’: Permission denied
find: ‘/etc/libvirt’: Permission denied
find: ‘/etc/containers/networks’: Permission denied
find: ‘/etc/sos/cleaner’: Permission denied
find: ‘/etc/ipsec.d’: Permission denied
find: ‘/etc/firewalld’: Permission denied
7、Save the process output to/tmp/output文件中,To save the error message to/tmp/errors文件中.
[[email protected] ~]$ find /etc -name passwd > /tmp/output 2> /tmp/errors
[[email protected] ~]$ cat /tmp/output
/etc/pam.d/passwd
/etc/passwd
[[email protected] ~]$ cat /tmp/errors
find: ‘/etc/lvm/archive’: Permission denied
find: ‘/etc/lvm/backup’: Permission denied
find: ‘/etc/lvm/cache’: Permission denied
find: ‘/etc/pki/rsyslog’: Permission denied
find: ‘/etc/pki/pesign’: Permission denied
find: ‘/etc/ssh/sshd_config.d’: Permission denied
find: ‘/etc/grub.d’: Permission denied
find: ‘/etc/sssd’: Permission denied
find: ‘/etc/polkit-1/rules.d’: Permission denied
find: ‘/etc/polkit-1/localauthority’: Permission denied
find: ‘/etc/cups/ssl’: Permission denied
find: ‘/etc/cni/net.d’: Permission denied
find: ‘/etc/nftables’: Permission denied
find: ‘/etc/audit’: Permission denied
find: ‘/etc/sudoers.d’: Permission denied
find: ‘/etc/libvirt’: Permission denied
find: ‘/etc/containers/networks’: Permission denied
find: ‘/etc/sos/cleaner’: Permission denied
find: ‘/etc/ipsec.d’: Permission denied
find: ‘/etc/firewalld’: Permission denied
8、忽略并丢弃错误消息,But save the process output message.
[[email protected] ~]$ find /etc -name passwd > /tmp/export 2> /dev/null
[[email protected] ~]$ cat /tmp/export
/etc/pam.d/passwd
/etc/passwd
[[email protected] ~]$ cat /dev/null
9、The output and generate error messages stored together.
[[email protected] ~]$ find /etc -name passwd &> /tmp/save-both
[[email protected] ~]$ cat /tmp/save-both
find: ‘/etc/lvm/archive’: Permission denied
find: ‘/etc/lvm/backup’: Permission denied
find: ‘/etc/lvm/cache’: Permission denied
find: ‘/etc/pki/rsyslog’: Permission denied
find: ‘/etc/pki/pesign’: Permission denied
find: ‘/etc/ssh/sshd_config.d’: Permission denied
/etc/pam.d/passwd
find: ‘/etc/grub.d’: Permission denied
/etc/passwd
find: ‘/etc/sssd’: Permission denied
find: ‘/etc/polkit-1/rules.d’: Permission denied
find: ‘/etc/polkit-1/localauthority’: Permission denied
find: ‘/etc/cups/ssl’: Permission denied
find: ‘/etc/cni/net.d’: Permission denied
find: ‘/etc/nftables’: Permission denied
find: ‘/etc/audit’: Permission denied
find: ‘/etc/sudoers.d’: Permission denied
find: ‘/etc/libvirt’: Permission denied
find: ‘/etc/containers/networks’: Permission denied
find: ‘/etc/sos/cleaner’: Permission denied
find: ‘/etc/ipsec.d’: Permission denied
find: ‘/etc/firewalld’: Permission denied
10、The output and the generated error attached to an existing file.
[[email protected] ~]$ find /etc -name passwd >> /tmp/save-both 2>&1
[[email protected] ~]$ cat /tmp/save-both
find: ‘/etc/lvm/archive’: Permission denied
find: ‘/etc/lvm/backup’: Permission denied
find: ‘/etc/lvm/cache’: Permission denied
find: ‘/etc/pki/rsyslog’: Permission denied
find: ‘/etc/pki/pesign’: Permission denied
find: ‘/etc/ssh/sshd_config.d’: Permission denied
/etc/pam.d/passwd
find: ‘/etc/grub.d’: Permission denied
/etc/passwd
find: ‘/etc/sssd’: Permission denied
find: ‘/etc/polkit-1/rules.d’: Permission denied
find: ‘/etc/polkit-1/localauthority’: Permission denied
find: ‘/etc/cups/ssl’: Permission denied
find: ‘/etc/cni/net.d’: Permission denied
find: ‘/etc/nftables’: Permission denied
find: ‘/etc/audit’: Permission denied
find: ‘/etc/sudoers.d’: Permission denied
find: ‘/etc/libvirt’: Permission denied
find: ‘/etc/containers/networks’: Permission denied
find: ‘/etc/sos/cleaner’: Permission denied
find: ‘/etc/ipsec.d’: Permission denied
find: ‘/etc/firewalld’: Permission denied
find: ‘/etc/lvm/archive’: Permission denied
find: ‘/etc/lvm/backup’: Permission denied
find: ‘/etc/lvm/cache’: Permission denied
find: ‘/etc/pki/rsyslog’: Permission denied
find: ‘/etc/pki/pesign’: Permission denied
find: ‘/etc/ssh/sshd_config.d’: Permission denied
/etc/pam.d/passwd
find: ‘/etc/grub.d’: Permission denied
/etc/passwd
find: ‘/etc/sssd’: Permission denied
find: ‘/etc/polkit-1/rules.d’: Permission denied
find: ‘/etc/polkit-1/localauthority’: Permission denied
find: ‘/etc/cups/ssl’: Permission denied
find: ‘/etc/cni/net.d’: Permission denied
find: ‘/etc/nftables’: Permission denied
find: ‘/etc/audit’: Permission denied
find: ‘/etc/sudoers.d’: Permission denied
find: ‘/etc/libvirt’: Permission denied
find: ‘/etc/containers/networks’: Permission denied
find: ‘/etc/sos/cleaner’: Permission denied
find: ‘/etc/ipsec.d’: Permission denied
find: ‘/etc/firewalld’: Permission denied
二、构建管道
说明:Pipeline is a sequence of one or more orders,用竖线字符“|”分隔;Pipeline will be the first command of the standard output connected to the next command's standard input.想象一下:Data is through the pipe flow from one process to another process,Every command slightly in its flow through the pipe to do some changes.
重定向:Will send file to standard output or standard input from a file.
管道:Will be a process of standard output is sent to another process standard input.
示例
1、使用lsThe output of the command and uselessOn the terminal display output in the form of a once.
[[email protected] ~]$ ls -l /usr/bin | less
2、lsThe output of the command towc -l,Statistics from the userlsReceive the number of lines,And the bank number displayed in the end.
[[email protected] ~]$ ls | wc -l
9
3、Input in the pipe out of the current query results before10行,And the final result is redirected to a file.
[[email protected] ~]$ ls -t | head -n 10 > /tmp/ten-last
[[email protected] ~]$ cat /tmp/ten-last
rhel-8.6-x86_64-dvd.iso
Downloads
Desktop
Documents
Music
Pictures
Public
Templates
Videos
三、管道、重定向和tee命令
When redirection and pipe combination,shellWill first set the whole pipeline,And then redirect input/输出.If in the middle of the pipe using the output redirection,The output will be transferred to file,Rather than heading to the pipeline of the next command.teeOrder to overcome this limitation;在管道中,teeCopies of its standard input to its standard output,And also to standard output is redirected to the designated command parameter file.Imagine if the data flowing through a pipe of water,那么可将teeVisual into pipesT形接头,Responsible for the flow of output in both directions.
示例
1、将ls命令的输出重定向到文件,And the output to aless,So that on the terminal display in the form of one screen at a time.
[[email protected] ~]$ ls -l | tee /tmp/save-both | less
2、If at the end of pipe to usetee,You can save the final output of the command and output to the terminal at the same time.
[[email protected] ~]$ ls -t | head -n 10 | tee /tmp/ten-lest
rhel-8.6-x86_64-dvd.iso
Downloads
Desktop
Documents
Music
Pictures
Public
Templates
Videos
[[email protected] ~]$ cat /tmp/ten-lest
rhel-8.6-x86_64-dvd.iso
Downloads
Desktop
Documents
Music
Pictures
Public
Templates
Videos
边栏推荐
猜你喜欢
论文解读:Deep-4MCW2V:基于序列的预测指标,以鉴定大肠杆菌中的N4-甲基环胞嘧啶位点
Wallys/QCA 9880/802.11ac Mini PCIe Wi-Fi Module, Dual Band, 2,4GHz / 5GHz advanced edition
Ark: Survival Evolved Open Server Port Mapping Tutorial
动手学深度学习_风格迁移
mysql如何查看所有复合主键的表名?
100+开箱即用的AI工具箱;程序员150岁长寿指南;『地理空间数据科学』课程资料;Graphic数据可视化图表库;前沿论文 | ShowMeAI资讯日报
Can't install the Vmware virtual machine on the Ark Kai server?
方舟开服务器Vmware虚拟机安装不上?
One-key login principle of local number
The strongest distributed lock tool: Redisson
随机推荐
Apache Doris 社区 PMC 杨政国:开源项目如何在自身和社区的需求中取得平衡?
win10 uwp 手动锁Bitlocker
JSDN blog system
How to play with container local storage through open-local? | Dragon Lizard Technology
ASP.NET Core依赖注入之旅:针对服务注册的验证
jmeter - record script
The senior told me that the MySQL of the big factory is connected through SSH
动手学深度学习_全卷积网络 FCN
动态RDLC报表(一)
2022秋招面试宝典,啃完面试稳了
艺术与科技的狂欢,云端XR支撑阿那亚2022砂之盒沉浸艺术季
动态RDLC报表(五)
【解决】虚拟机VMware通过局域网连接机器人no route to host
mysql如何查看所有复合主键的表名?
01 -- 钉钉机器人
Cortex-A7 MPCore Architecture
【ROS2原理9】 QoS - 截止日期、活跃度和寿命
好的架构是进化来的,不是设计来的
Can't install the Vmware virtual machine on the Ark Kai server?
那些关于DOM的常见Hook封装(二)