The filename statement’s pipe option allows you to direct the output of operating system commands into SAS for further processing. Usefully, the Windows dir command (with its /s switch) and the UNIX equivalent ls allow you get a file listing into SAS. For example, here’s how you extract the list of files in your UNIX home directory into SAS:
filename DIRLIST pipe ‘ls ~’;
data dirlist;
length filename $200;
infile dirlist length=reclen;
input buffer $varying200. reclen;
run;
Using the ftp option on the filename statement allows you to get a list of the files in a directory on a remote server, even one with a different operating system to that used on the client (PC or server), very useful for cases where cross-platform systems are involved. Here’s some example code:
filename dirlist ftp ‘ ‘ ls user=’user’ host=’host’ prompt;
data _null_;
length filename $200;
infile dirlist length=reclen;
input buffer $varying200. reclen;
run;
The PROMPT option will cause SAS to ask you for a password and the null string is where you would otherwise specify the name of a file.