Shell script Application (i) case

Case One

• Write a login welcome script for ROOT to report the number of processes in the current host, the number of logged-in users, and the disk usage of the root file system.

1. Using the VIM command in the /root directory is a new script file welcome.sh, which reads as follows:

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Note: ' {print $} ' is used here as a single quote, not a reverse apostrophe.

2. Add the Execute (x) permission to the welcome.sh file using the chmod command

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3. Modify the/root/.bash_profile file to invoke the welcome.sh script every time the root user logs on to the system

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4. Verify: Log back in with the root user to verify the output information of the Welcome script

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Case Two

• Write start, stop, status three script programs to start and stop various system services.

1. use the VIM command to Create a new script file in the/bin directory start.sh

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2. Set x permissions

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3. Modify aliases

Alias start= ' start.sh '//To enter start direct execution need to create a new alias (this alias is temporary, the system restarts after the failure, if the permanent effect, also need to modify the/ROOT/.BASHRC configuration file, add this line command)

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4. Test scripts

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The script file stop and status are similar to start and are no longer described here.

Case Three

• Filter out the MAC address of the ETH0 network card and assign a value to the variable hwaddr.

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Case Four

• Write a small script sumsquare.sh to calculate the sum of squares of two integers.

1. Create a script

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2. Assigning Script Execution permissions

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3. Testing

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Case Five

• Write a small script memusage.sh to settle the memory usage based on the results of the free command.

1. Create a script

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Note: In a Linux system, the actual memory usage is recommended to calculate the ratio of total memory space, whichever is the used Buffers/cache. Also, because the bash shell does not support decimal operations, and the usage percentage is less than 1, you need to multiply the numerator by 100 before calculating the result.

2. Give script x permission

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3. Test scripts

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This article is from the "Network Technology" blog, please be sure to keep this source http://fjc365.blog.51cto.com/11891287/1874752

Shell script Application (i) case