I am connecting to an FTP server to download some gzipped files and I noticed something a bit disconcerting about the SIZE command and my google-fu has failed me.
ftp> size file0001.xml.gz 213 2524751 ftp> nlist -ltr ... -rw-r--r-- 1 anon anons 2515727 Jan 30 00:00 file0001.xml.gz ...
The file sizes are different, (2524751 != 2515727), as you can see. Why?
I've briefly read the RCF0959 FILE TRANSFER PROTOCOL (FTP) and there's no mention of the SIZE command, which I later found out to be a non-standard addition to the protocol.
Here's the bit about byte size, for convenience, from the RFC:
byte size There are two byte sizes of interest in FTP: the logical byte size of the file, and the transfer byte size used for the transmission of the data. The transfer byte size is always 8 bits. The transfer byte size is not necessarily the byte size in which data is to be stored in a system, nor the logical byte size for interpretation of the structure of the data.
What am I missing here?