Deleting Data¶
Since SAS operates on a row-by-row basis, we often have to make several intermediate datasets in the process of creating a clean dataset for analysis. To keep our project space clean we want to delete these files at the end of our scripts. To do this, we make use of the DELETE statement of PROC DATASETS.
Deleting Files with PROC DATASETS¶
The general syntax to delete a file or list of files is
proc datasets lib = (noprint);
delete /* list files here */;
quit;
run;
lib specifies the library where the files are located. noprint (optional) supresses printing to the log. After the delete we specify the files we want to delete. Here is an example to delete the files clean_data_pre and clean_data_merge located in the out library
proc datasets lib = out;
delete clean_data_pre clean_data_merge;
quit;
run;
We can also make use of the SAS wildcard character : to delete many files with a common prefix
proc datasets lib = out;
delete clean_data_:;
quit;
run;
Deleting All Files in a Library with KILL¶
Often times we use certain folders in our project space to store intermediate files that are byproducts of the build process (sometimes called dump). These folders can be filled with many files during a build process and it can be annoying to list them all out in the DELETE statement. In SAS we can delete all the files in a library using the KILL option to PROC DATASETS. For instance, to delete all the files in the library out we would write
proc datasets lib = out kill;
quit;
run;
We recommend using this sparingly to avoid accidently deleting important files.