Question

What I want to do is run a process on my server that acts like an FTP server. So people can upload things through “FTP” but really it’s a program I’m running that lets me put information about that file in a database and not really put the files where they say they’re going.

E.g. Website Templates. A user of my service wants to put up the template they are working on for a client of theirs, but wants to upload it through the FTP in their text editor. But I want to store that templates data in a database, process it to find out things about it then store it where I want to but still display it as being where the person put it for them.

Probably going to be very difficult but does anyone know if it’s possible?

Answer 1

FTP only defines the specifics of the transfer operation. How the actual storage is handled is up to whoever’s writing the server. This allows it to be filesystem-agnostic, so that the same protocol can be used against Unix, Windows, VMS, TRS-DOS, etc.

One option would be to find the source for an existing server that runs on your platform of choice and just “replace” the calls that deal with the file I/O.

dbfs.h:

#define open db_open
#define write db_write
#define close db_close

dbfs.c:

int open(...)
{
    /* create a memory buffer */
}

ssize_t write(...)
{
    /* write data to memory buffer */
}

int close(...)
{
    /* execute SQL insert statement to save memory buffer to db */
}

Existing server code:

#include <fcntl.h>
#include <unistd.h>
#include "dbfs.h" /* "replaces" system-defined file I/O routines */