Defines a function that plays the Mario theme while an experssion is executing (Linux only)

mario_beep

# The code below will probably only work on Linux and requires VLC on the path.
library(beepr)
library(stringr)

# Plays a file with vlc and returns the vlc instance's PID
play_vlc_pid <- function(fname) {
  system(paste("vlc -Idummy --no-loop --no-repeat --playlist-autostart --no-media-library --play-and-exit", fname), 
         ignore.stdout = TRUE, ignore.stderr=TRUE,wait = FALSE)
  ps_out <- system("ps -eo pid,comm,etime| grep vlc", intern=TRUE)
  
  # Find the pid
  pid_df <- read.table(textConnection(paste(ps_out, collapse="\n")), header=FALSE, 
                       stringsAsFactors=FALSE, col.names= c("pid", "command", "time"))
  vlc_pid <- pid_df$pid[ # Find the pid that is connected to a vlc
    str_detect(pid_df$time, "00:0\\d") & # that is less that 10 seconds old and
      which.min(as.numeric(str_extract(pid_df$time, "[0-9]+$"))) # youngest old.
    ]
  vlc_pid
}

# Plays the mario theme while expr is executing, plays the flag pole jingle when the execution have finished.
# The file "main-theme-overworld.mp3" has to be on the path.
# It can be downloaded from here: https://dl.dropboxusercontent.com/u/5304231/main-theme-overworld.mp3
mario_beep <- function(expr) {
  pid <-  play_vlc_pid("main-theme-overworld.mp3")
  expr
  system(paste("kill", pid))
  #system("pkill vlc")
  beep(8)
}

# Use it like this:
# mario_beep(Sys.sleep(10))