如果文本文件 bash 脚本中有多个列

Question

How to detect multiple columns inside if statement for bash scripting? I want to do something if there are multiple columns inside the text file.

Example:

I will output one command to file device.txt

If there is only one device, I will have just that name inside the document:

Device1:

If I have multiple devices I will have this inside the device.txt file:

Device1: Device2: Device3: 

I want to create if statement inside my bash script that will be triggered if there are multiple devices.

Answer 1

if [[ `awk 'NF > 1' device.txt` ]]; then
    command
fi

awk while start printing anything whenever the number of fields of a line exceeds one.

You could make it more elegant by using {exit 1} as the awk command to execute whenever the condition applies, but it does make it harder to understand what's going on, as than there is 'false' exit code when the condition applied, since finding no columns results in a 'successful` execution of the awk program.

Answer 2

最后我使用这个命令wc -w它做我需要的