Linux scripts delete files larger than the specified size

A question about how to automatically delete a specified file larger than 1 GB.

The batch processing code is as follows:

#! /Bin/bash
# When/var/log/syslog is greater than 1 GB
# Automatically back up and clear
# Note the usage of awk
If! [-F/var/log/syslog]
Then
Echo "file not exist! "
Exit 1
Fi
If ['LS-l/var/log/syslog | awk' {print $5} ''-gt $ (1024*1024)]
Then
Cat/var/log/syslog> ~ /Log/history # Back up logs
Echo >> ~ /Log/history # Add an empty line
Date> ~ /Log/history # record time
Echo "-------------------------------------"> ~ /Log/history
Echo>/var/log/syslog # Clear
Fi