You can also set up for the system to do it for you. Read the docs for the ftp command and the netrc file.

Here's a sample netrc:

machine foo.network-lynx.net
login don
password zebra
macdef init
cd /usr/local/test_data/reports
binary
mget *599*
exit
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and the command that invokes it:

system("ftp -in -N /var/web/scripts/netrc don@foo.network-lynx.net") 
       && die "Couldn't complete netrc ftp! $!\n";
[download]

Note that the netrc file MUST ONLY be readable by the user that invokes the script.