FTP is the most common means of moving files to and from a server. When the FTP specification was written, certain convenience features were recommended to client implementers. This was done through four data type definitions. With these definitions, the clients can perform transformations of the data to ease the burden of performing these transformations yourself every time you upload a file.
The data types are: ASCII, EBCDIC, Image, and Local. The first two are different character sets that the local file can be converted to during transmission to the other server. Image is now commonly known as “binary mode” and it transfers the data without changing it in any way. Local allows hosts to specify custom byte sizes for storage and transmission. For this article, I will be focusing on ASCII and Image and what can go wrong if you choose the incorrect transfer mode.
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