The INFILE/FILE User Exit Facility provides an interface
for accessing user exit modules during the processing of external
files in a SAS DATA step. A user exit module (or user exit) consists
of several functions that you write in order to perform special processing
on external files. For example, you can write user exits that inspect,
modify, delete, or insert records. Here are some more specific examples
of how user exits can be used:
-
encrypting and decrypting data
-
compressing and decompressing data
-
translating data from one character
encoding to another
If a user exit is active,
SAS invokes it at various points during the processing of an external
file.
Note: The INFILE/FILE User Exit
Facility is provided for host access methods only. These methods include
BSAM, BPAM, VSAM, and VTOC. Portable access methods, such as FTP,
HTTP, e-mail, socket, and so on, do not use this facility.