This evening, by checking the data, I learned that to make the docker container run in the background, you should add tail - f /dev/null after the command. However, I don't understand the meaning of each letter in the command tail - f /dev/null. I only know that it can make the docker container run in the background. I want to know the meaning of each letter in the command tail - f /dev/null,Thanks in advance.
CodePudding user response：
there is an typo in your command. Remove the whitespace between - and f then it should work.
tail is responsible to read the last 10 lines of a file -f parameter means follow all lines which will be added to the file.
This is the reason why the terminal will stay open.
/dev/null is an linux device.
BR Sebastian
CodePudding user response：
I think you mean tail -f /dev/null
From man tail:
DESCRIPTION
Print the last 10 lines of each FILE to standard output.
.
.
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-f, --follow[={name|descriptor}]
output appended data as the file grows;
an absent option argument means 'descriptor'
/dev/null is a virtual device file that will appear to tail as if it were a "normal" file.
In plain English, this will make tail keep waiting for new data in /dev/null, but there will never be any since it's a special type of device (essentially a black hole).