Linux将顶部输出存储到文件中

Question

I wanted to execute the top command as shown below and store the output to a file.

xyz.sh

#!/bin/sh 
while :
do
top -n 1 
sleep 5
done

when I run the code, It executes and produces the output fine:

sh xyz.sh 

but when I try to execute the code in background its getting killed.

sh xyz.sh > xyz.log &

any ideas how can I capture top output?

Answer 1

The top cli command behaves different to what you might be used to from other utilities. This is because it does not work in a typical filter like way reading from stdin and writing to stdout. Instead it emulates a terminal. This means that you cannot simply redirect its output, because there is no output written to standard out.

Check the man page (which you should always do...). You will notice the -b flag which changes that behaviour. This will allow you to do what you try.