The use of automated scripts have made it extremely important to understand error conditions in a programmatic way. Here are a couple of the ways you can check for errors in your automated SAS scripts.
SYSERR - This macro variable should have a value of 0 (zero) if the data or proc step completed successfully.
put something here;
%put NOTE: This step returned a value of $SYSERR;
SYSCC - This is the value that SAS would return to the operating system if it were to exit at that point. You can use this to see if there were errors in your script up until this point. The value of SYSERR is reset upon each data or proc step. However, SYSCC doesn't reset unless the user resets it within the script. This can be useful if you want to force SAS to exit in a success or fail status.
NOTE - It is important to know that it is well documented that both of these variables have flaws. There are conditions that don't trigger errors that might not be intuitive. If you are relying heavily on these variables for code success, you should take a minute to read the SAS documentation around what does and doesn't constitute an error.