Technology Tales

Automating FTP I: UNIX and Linux

11^th April 2008

Having got tired of repeated typing in everything at the prompt of an interactive command line FTP session and doing similar things via the GUI route, I started to wonder if there was a scripting alternative and, lo and behold, I found it after a spot of googling. There are various opportunities for its extension such as prompting for username and password instead of the risky approach of including them in a script or cycling through a directory structure but here's the foundation stone for such tinkering anyway:

HOSTNAME='ftp.server.host'
USER='user'
PSSWD='password'
REP_SRC='source_directory'
REP__DEST='destination_directory'
FILENAME='*'

rm -rf log_file.tmp

cd "${REP_DEST}"

ftp -i -n -v <<EndFTP >>log_file.tmp 2>>log_file.tmp
open ${HOSTNAME}
user ${USER} ${PSSWD}
prompt
cd "${REP_SRC}"
mget "${FILENAME}"
EndFTP

cd ~

Using SAS FILENAME statement to extract directory file listings into SAS

30^th May 2007

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 and Linux equivalent ls allow you to get a file listing into SAS. For example, here's how you extract the list of files in your UNIX or Linux 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.