questions on sas formating issue

In the following sas code segment, what do the "lib=sasuser " and "select" mean here? Thanks.

proc f开发者_StackOverflowormat lib=sasuser cntlout = sasuser.fmtdata;
     select $airport;
run;

The code you posted will read the formats catalog from the sasuser library (sasuser.formats), selecting only the custom character format $airport (out of the many other possible formats that might also be contained in the catalog) and write its definition to a SAS table (sasuser.fmtdata).

Once the format definition is in a SAS table you can use it to generate a report on the definition of the format. You can also modify the definition of the format by modifying the table contents and feeding it back into proc format using the cntlin option to create or update a format in a format catalog by reading its definition from an input SAS table.

You can find out more about the various proc format options on the SAS support site at http://support.sas.com/documentation/cdl/en/proc/61895/HTML/default/a000063536.htm