[Comprehensive explanation of Linux commands] 084. Analysis of common Linux commands: dpkg-trigger, iptraf and lsattr

dpkg-trigger

Package triggers under Debian Linux

Additional information

dpkg-triggerCommand is a package trigger under Debian Linux.

grammar

dpkg-trigger [选项] [参数]

options

• --check-supporteddpkg: Check whether the running program supports triggers. If the return value is 0, it means triggers are supported.
• --help: Display help information;
• --admindir=<目录>: Set dpkgthe directory where the database is located;
• --no-act: Only for testing, does not perform any operation;
• --by-package=<软件包>: Override trigger waiter.

parameter

Trigger name: Specify the trigger name.

iptraf

Monitor network card traffic in real time

Additional information

iptrafThe command can monitor network card traffic in real time and generate information such as network protocol packet information, Ethernet information, network node status, and IP checksum errors.

grammar

iptraf [选项]

options

• -i 网络接口: Immediately enable IP traffic monitoring on the specified network interface;
• -g: Start generating summary status information of the network interface immediately;
• -d 网络接口: Immediately start monitoring detailed network traffic information on the specified network interface;
• -s 网络接口: Immediately start monitoring TCP and UDP network traffic information on the specified network interface;
• -z 网络接口: Display packet count on the specified network interface;
• -l 网络接口: Immediately start monitoring LAN workstation information on the specified network interface;
• -t 时间: Specify iptrafthe time for command monitoring;
• -B: Redirect the annotation output to /dev/null, close the annotation input, and run the program as a background process;
• -f:Clear all counters;
• -h: Display help information.

lsattr

View the second extended file system attribute of a file

Additional information

lsattrCommand is used to view the second extended file system attributes of a file.

grammar

lsattr [选项] [参数]

options

• -E: Can display the current value of the device attribute, but this current value is obtained from the user device database, not directly from the device.
• -D: Displays the name of the attribute, the attribute's default value, description and a flag indicating whether the user can modify the attribute value.
• -R: Recursive operation mode;
• -V: Display the version information of the command;
• -a: List all files in the directory, including hidden files.

lsattrSeveral frequently used options -D, -E, and -Rthese three options cannot be used together. They are mutually exclusive. Frequently used options include -l, -H. When using lsattrit, you must point out the specific device name and use -lthe option to indicate the logical name of the device to be displayed. Otherwise, you need to use -c, -s, -tand other options to uniquely determine an existing device.

parameter

File: Specifies the file name that displays the file system attributes.

example

lsattr -E -l rmt0 -H
lsattr -EO -l rmt0

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