print-netstat.R

library(stringi)
library(data.table)
library(ggplot2)
library(scales)

Sys.setlocale(category="LC_TIME", "en_US.UTF-8")  # strptime

STRPTIME <- "%a %b %d %H:%M:%S EST %Y"

ARGS <- commandArgs(trail = TRUE)

readKernel <- function(line) {
  timestamp.s <- substr(line, 1, 28)  # "Tue Jan 12 15:25:08 EST 2016"
  timestamp <- strptime(timestamp.s, STRPTIME, tz="America/New_York") # EST

  drops <- as.numeric(stri_extract_first_regex(line, "\\d+(?= packet receive errors)"))  # number preceding a text
  data.frame(Time=timestamp, PktDropAtRcvr=drops)
}

dropA.df <- rbindlist( Map(readKernel, readLines(ARGS[1])) )
dropB.df <- rbindlist( Map(readKernel, readLines(ARGS[2])) )
# nrow(drop.df)
# ncol(drop.df)
# dropA.df[1:3, ]

g <- ggplot()
svg("r01.svg", width=20, height=8)
# png("r01.png", width=2000, height=800)
g +
  geom_point(data=dropA.df, aes(Time, PktDropAtRcvr), color="red") +
  geom_point(data=dropB.df, aes(Time, PktDropAtRcvr), color="blue") +
  scale_x_datetime(labels=date_format("%b%d %H:%M", tz="America/New_York"), breaks=date_breaks("3 hour"), minor_breaks=date_breaks("30 min"))
dev.off()