Is there way to track progress on a mclapply?

Question

I love the setting .progress = \'text\' in plyr\'s llply. However, it causes my much anxiety to not know how far along an mclapp

Answer 1

Based on the answer of @fotNelson, using a progress bar instead of line by line printing and calling an external function with mclapply.

library('utils')
library('multicore')

prog.indic <- local({ #evaluates in local environment only
    f <- fifo(tempfile(), open="w+b", blocking=T) # open fifo connection
    assign(x='f',value=f,envir=.GlobalEnv)
    pb <- txtProgressBar(min=1, max=MC,style=3)

    if (inherits(fork(), "masterProcess")) { #progress tracker
        # Child
        progress <- 0.0
        while (progress < MC && !isIncomplete(f)){ 
            msg <- readBin(f, "double")
                progress <- progress + as.numeric(msg)

            # Updating the progress bar.
            setTxtProgressBar(pb,progress)
            } 


        exit()
        }
   MC <- 100
   result <- mclapply(1:MC, .mcfunc)

    cat('\n')
    assign(x='result',value=result,envir=.GlobalEnv)
    close(f)
    })

.mcfunc<-function(i,...){
        writeBin(1, f)
        return(i)
    }

Assigning the fifo connection to the .GlobalEnv is necessary to use it from a function outside of the mclapply call. Thanks for the questions and the previous replies, I had been wondering how to do this for a while.