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R : readBin and writeBin ( for storing/retrieving MySQL BLOBs or LONGBLOBs )
plot_binary <- paste(readBin("temp.png", what="raw", n=1e6), collapse="")

> f = file ( "backIntoFile.png", "wb")
> writeBin(object = plot_binary, con = f )
> close(f)

plot_binary <- readBin("temp.png", what="raw", n=1e6)

> f = file ( "backIntoFile.png", "wb")
> writeBin(object = plot_binary, con = f )
> close(f)

binary.string <- paste(readBin("temp.png", what="raw", n=1e6), collapse="-")

> split = strsplit ( binaryString, split = "-" )
> split = unlist ( split )
> back.to.binary = as.raw ( as.hexmode ( split ) )
> f = file ( "backIntoFile.png", "wb")
> writeBin(object = back.to.binary, con = f )
> close(f)

sz <- as.integer(system("stat --format %s temp.png", intern=T))

plot_binary <- paste(readBin("temp.png", what="raw", n=1e6), collapse="")
theBinary <- unlist(lapply((1:(nchar(plot_binary)/2))*2, function(i)return(as.raw(as.hexmode(substr(plot_binary,i-1,i))))))

# Helper function I use
Paste <- function(string, vals)
{
    string <- gsub(x = string, pattern = '\?', replacement = "%s")
    result <- do.call(sprintf, as.list(c(string,vals)))
    return(result)
}
# conn is a RMySQL connection object
DbInsertImage <- function( conn, link.to.file )
{

        binary = readBin ( link.to.file , what = "raw", n = 1e6 )
        binary.str = paste ( binary, collapse = "" )
        statement = Paste ( "CALL InsertImage('?')" , c(binary.str))
        dbSendQuery(conn, statement )
        return(GetIdentity(conn)) # one of my helper functions ;
            # it returns the "LAST INSERT ID"
}

#conn is a RMySQL connection object
DbDownloadImage <- function( conn, id, destination)
{

    query = "SELECT Data FROM Image WHERE Id = ? LIMIT 1"
    query = Paste( query, c( id ) )
    result = dbGetQuery(conn, query )$Data[1]

    sst <- strsplit(result, "")[[1]]
    result <- paste0(sst[c(TRUE, FALSE)], sst[c(FALSE, TRUE)])
    result <- as.raw ( as.hexmode ( result ) )

    f = file ( destination, "wb")

    writeBin(object = result, con = f )
    close(f)
}