Linux command explanation: [7] Get command Help

In the maintenance and use of the Linux system, often forget how to use the command, if there is no corresponding data, then how to do? Do not worry, the system itself provides a detailed manual for users to query, the following small series on the CentOS6.4 system as an example of how to get command Help.

Tools/Materials

• CentOS6.4

Method/Step

2. When you encounter a strange command, or want to know what the command is, you can enter the type command name at the prompt to see the command explanation given by the system. The three commands in the example explain that the first is the command interpretation of type: It is the shell's internal command, the second is the command explanation of CP: It is the command alias of Cp-i, and the third is the command explanation of LS: it is the command alias of LS--color=auto.

4. If you want to know the location of the executable can use the command which, the use of the which command name , the example uses the which command to see the CP command and the exact location of the LS command, but the location of the CD command is not queried, The reason is that the CD command is the shell's internal command, which cannot be queried.

6. If you are not sure how to use the command, you can use the Help command name to get a helping document. The diagram shows a help document for the CD command obtained using the command assist CD , which shows that the CD command can contain the L or P parameters, as well as the parameter "dir".

8. Many systems also support a --help option that allows you to view the parameter descriptions supported by the command, such as the parameter description of the LS command you want to see, and the command LS--help can be used . The diagram shows the option description for some LS, which shows that the LS command contains a, a, B, b and other parameters, each of which has a detailed description of the use.

10. Finally, a command man is introduced, which allows you to view the official document of the command, using the command name . The figure lists some of the official documents that you see Using the command man ls , which contains a lot of content and is interesting to study carefully.

Linux command explanation: [7] Get command Help