Shell scripts periodically empty log files larger than 1G _linux shell

A question about how to automatically delete a specified file after it is larger than 1GB.
The batch code is as follows:

Copy Code code as follows:

#!/bin/bash
# when the/var/log/syslog is greater than 1GB
# automatically back it up and empty
# Note the use of awk here
if! [-f/var/log/syslog]
Then
echo "File not exist!"
Exit 1
Fi
If [' Ls-l/var/log/syslog|awk ' {print $} '-gt $ ((1024*1024))]
Then
Cat/var/log/syslog >> ~/log/history # Log backup
echo >> ~/log/history # Add a blank line
Date >> ~/log/history # record time
echo "-------------------------------------" >> ~/log/history
echo >/var/log/syslog # Empty
Fi