To truncate a UNIX binary log file, you can use the truncate command. This command allows you to shrink or extend the size of a file to a specified length.
Here is the basic syntax for using truncate:
truncate -s SIZE file
Where SIZE is the size that you want the file to be, and file is the path to the file that you want to truncate.
For example, to truncate a file called log.bin to a size of 100 bytes, you would use the following command:
truncate -s 100 log.bin
Note that truncate does not modify the contents of the file, it simply changes the size of the file. If you want to clear the contents of the file, you can use the echo command to write an empty string to the file, like this:
echo -n "" > log.bin
This will overwrite the contents of the file with an empty string, effectively clearing the file.