Get a tidy representation of disk usage

disk_use.R

library(tidyverse)

rm_rownames <- function(z) {
  rownames(z) <- NULL
  z
}

sz_message <- function(sz, p_nm, ttl, bs) {
  p_mn <- round(mean(sz[[p_nm]], na.rm = T))
  message(
    paste(
      "It appears you're using ", 
      p_mn, "% of a total ", ttl, bs, " of dev-level blocks", 
      sep = ""
      )
  )
}

# test <- 
#   system("sudo -kS df -h /", input = rstudioapi::askForPassword())
tidy_sys_df <- function(blocksize) {
  stopifnot(blocksize %in% c("K", "M", "G", "T", "P", "E", "Z", "Y"))
  the_command <- paste("df -B", blocksize, sep = "")
  p_bs <- function(the_x) paste(tolower(blocksize), the_x, sep = "_")
  bs_nm <- p_bs("blocks")
  pu_nm <- p_bs("used")
  system(the_command, intern = T) %>% 
    map(~ strsplit(.x, "\\ {1,}")) %>% 
    (function(a) {
      nms <- a[[1]][[1]]
      #nms <- nms[-length(nms)]
      a[1] <- NULL
      #list(nm = nms, rws = a)
      # THERES A SAFER WAY TO SELECT FOR THE CORRECT NAME
      map(a, ~ set_names(flatten_chr(.x), nm = nms[-7])) %>% 
        reduce(rbind) %>% 
        rm_rownames()
    }) %>% 
  as.data.frame(stringsAsFactors = FALSE) %>%  
  rename_all(tolower) %>% 
  rename_all(
    function(x) {
      reduce2(
        c("%",     "^[^a-z]", "[^a-z]", "^used$"), 
        c("_perc", "",           "_",    pu_nm), 
        function(a, b, d) gsub(b, d, a), 
        .init = x
      )
   }) %>% 
  mutate(
    u_units  = str_extract(!!pu_nm, "[A-Za-z]"),
    bs_units = str_extract(!!bs_nm, "[A-Za-z]"),
    a_units  = str_extract(available, "[A-Za-z]")
    ) %>%
  modify_at(c(bs_nm, pu_nm, "available", "use_perc"), ~ as.numeric(gsub("[^0-9]", "", .x))) %>% 
  filter(grepl("dev", filesystem)) %>% 
  (function(a) {
    message(paste("Using", bs_nm, "as the blocksize variable name and", pu_nm, "as the used blocksize name"))
    sz_message(a, "use_perc", round(sum(a[["available"]]) / mean(a[["use_perc"]] / 100)), blocksize)
    a
    })
}