user_loc2rem.c

// user_loc2rem.c (rclient1)
// Andrew Mauragis
// Due 4/25/13
//
// This is a sample client program for linking with rclient.
// This program copies a remote file specified by the argument array to the
// local machine in the current working directory.
//
// Note, because there are no provisions for a remote Stat command, file
// permissions are not perserved.

#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>

#include "rclient.h"
#include "rpcdefs.h"

#define BUFFER_SIZE 512

// entry function
//
// To be called from rclient's main function, argc and argv are trimmed
// in rclient to remove the host address and port number
//
// returns an error code like a main() would.
int entry(int argc, char* argv[])
{
    // first we pull in the file name from the argument array
    if (argc < 2)
    {
        fprintf(stderr,"Not enough arguments.  Specify a filename\n");
        return ARGS_ERROR;
    }
    char* filename = argv[1];

    // open up the file to copy remotely
    int locfd = open(filename, O_RDONLY, 0000);
    if (locfd < 0)
    {
        perror("[Local] Open Error");
        return OPEN_ERROR;
    }
    // get permissions of local file
    struct stat s;
    if (0 > fstat(locfd, &s))
    {
        perror("[Local] Stat Error");
        return STAT_ERROR;
    }

    // open/create the remote copy
    int remfd = Open(filename, O_CREAT | O_WRONLY, s.st_mode);
    if (remfd < 0)
    {
        perror("[Remote] Open Error");
        return OPEN_ERROR;
    }

    // now we read locally and write remotely
    int bytesRead;
    unsigned char buf[BUFFER_SIZE];
    while ((bytesRead = read(locfd, &buf, BUFFER_SIZE)) > 0)
    {
        if (0 >= Write(remfd, &buf, bytesRead))
        {
            perror("[Remote] Write Error");
            return WRITE_ERROR;
        }

    }
    if (bytesRead < 0)
    {
        perror("[Local] Read Error");
        return READ_ERROR;
    }

    // now we close the local and remote fds
    if (0 > close(locfd))
    {
        perror("[Local] Close Error");
        return CLOSE_ERROR;
    }
    if (0 > Close(remfd))
    {
        perror("[Remote] Close Error");
        return CLOSE_ERROR;
    }

    return 0;
}

// This is code that was used for debugging during the development of the
// client and server.

// TESTING CODE: 

// int rslt = Open("BULLETS", O_CREAT | O_WRONLY, 0644);
// // printf("I opened fd: %d\n", rslt);
// // perror("Open");

// // printf("I'm going to try to write 'dicks dicks dicks\\n' to a file\n");
// int writeval = Write(rslt,"dicks dicks dicks\n", 19);
// perror("Write");

// // printf("Write return: %d\n", writeval);

// int closeval = Close(rslt);
// perror("Close");
// // printf("Close return: %d\n",closeval);


// // now lets try to read it back and print it out
// int fd = Open("BULLETS", O_RDONLY, 0000);
// perror("Open");
// // printf("I opened fd %d for reading.\n", fd);
// char buf[18];
// int readval = Read(fd, &buf, 17);
// perror("Read");
// // printf("I read %d bytes.\n", readval);
// buf[17] = 0;

// closeval = Close(fd);
// perror("Close");
// // printf("I closed with return val %d\n", closeval);

// // printf("The buffer I read was:<%s>\n", buf);

// fd = Open("BULLETS", O_WRONLY, 0644);
// perror("Open");
// Lseek(fd, 0, SEEK_SET);
// perror("Lseek");
// Write(fd, "DICK", 4);
// perror("Write");
// Close(fd);
// perror("Close");