`get` command creates non-existent files

[GoldBinocle]

How to reproduce

1. Compile using make
2. Start the server: ./bin/server/server_ftp.out
3. Start the client: ./bin/client/client_ftp.out
4. Type command on the client side
   4.1 First list the existing file in the project

CLIENT=> FTP Client started up. Attempting communication with server @ 127.0.0.1:8487...

        > ls
        FILE:   Makefile
        FILE:   TODO
        DIR:    .git
        FILE:   client_ftp_functions.c
        FILE:   server_ftp_functions.c
        DIR:    ..
        FILE:   client_ftp.h
        FILE:   commons.c
        FILE:   file_transfer_functions.c
        FILE:   server_ftp.h
        FILE:   commons.h
        FILE:   server_ftp.c
        DIR:    bin
        FILE:   README
        DIR:    .
        FILE:   .gitignore
        DIR:    obj
        FILE:   file_transfer_functions.h
        FILE:   .vimrc.custom.FTP
        FILE:   client_ftp.c

4.2 Then try to get a file that does not exist (file_not_exist)

        > get file_not_exist
        File found; processing
        1 data packet(s) received.
        0 byte(s) written.

4.3 List the file after the get command

        > ls
        FILE:   Makefile
        FILE:   TODO
        DIR:    .git
        FILE:   client_ftp_functions.c
        FILE:   file_not_exist
        FILE:   server_ftp_functions.c
        DIR:    ..
        FILE:   client_ftp.h
        FILE:   commons.c
        FILE:   file_transfer_functions.c
        FILE:   server_ftp.h
        FILE:   commons.h
        FILE:   server_ftp.c
        DIR:    bin
        FILE:   README
        DIR:    .
        FILE:   .gitignore
        DIR:    obj
        FILE:   file_transfer_functions.h
        FILE:   .vimrc.custom.FTP
        FILE:   client_ftp.c
        > 

We can see that file_not_exist is created.

Analysis

FTP/server_ftp_functions.c

Lines 51 to 69 in 96c1a35

	void command_get(struct packet* shp, struct packet* data, int sfd_client)
	{
	int x;
	FILE* f = fopen(shp->buffer, "rb"); // Yo!
	shp->type = INFO;
	shp->comid = GET;
	strcpy(shp->buffer, f ? "File found; processing" : "Error opening file.");
	//printpacket(shp, HP);
	data = htonp(shp);
	if((x = send(sfd_client, data, size_packet, 0)) != size_packet)
	er("send()", x);
	if(f)
	{
	shp->type = DATA;
	send_file(shp, data, sfd_client, f);
	fclose(f);
	}
	send_EOT(shp, data, sfd_client);
	}

The command_get function should first check the existence of the file to transfer.