ru.md

I wrote this because /usr/bin/time is very low time resolution (10 ms) with a very hard to read default format and for a very long time (early 90s?) various OSes have provided better. When faced with the question "What is CPU?", perhaps the getrusage/wait4 answer of ru can be a first step.

Usage: (***NOT*** a cligen utility)

  ru [-whatiscpu] <prog> [prog args...]

No options => as if -hit; else selected subset.

Flags all in arg 1 & mean:
  w  w)rapped output without row labels (to get fields by row, e.g. grep)
  h  h)uman readable formats with (h)our:minute:seconds, MiB, etc. units
  a  a)ll of the below, in the same order
  t  t)ime,mem (wall, user, system time, CPU utilization, max Resident)
  i  i)o (inBlocks, outBlocks, swaps, majorFaults, minorFaults)
  s  s)witch/stack/sharing (volCtxSw, involSw, stack, txtResShr, datResShr)
  c  interprocess (c)ommunications (signals, IPC sent, IPC received)
  p  p)lain output (no ANSI SGR color escapes)
  u  u)nwrapped output with field labels (to get fields by column, e.g. awk)

man getrusage | man time give more details on the various stats this small Nim program can print.

You can put options in the RU environment variable. Compared to time(1), this is higher precision with more modern and controlled units.