sleep — Pause shell execution for a fixed duration across all 5 shells

Equivalents in every shell

sleep 5

sleep 5

sleep 5

Start-Sleep -Seconds 5

timeout /t 5 /nobreak

Worked examples

sleep 0.5

sleep 0.5

Start-Sleep -Milliseconds 500

timeout /t 1 /nobreak >NUL

while ! curl -fs http://app/health; do sleep 5; done

while not curl -fs http://app/health; sleep 5; end

while ($true) { try { Invoke-RestMethod http://app/health; break } catch { Start-Sleep -Seconds 5 } }

:loop\r\ncurl -fs http://app/health || (timeout /t 5 /nobreak >NUL & goto loop)

sleep 2m

sleep 2m

Start-Sleep -Seconds 120

timeout /t 120 /nobreak >NUL

Gotchas

• BusyBox `sleep` (Alpine, embedded Linux, many Docker images) accepts ONLY integer seconds — `sleep 0.5` errors with `sleep: invalid number \'0.5\'`. If your image is `alpine:3`, every sub-second wait needs a workaround like `sleep 1` rounded up, or installing `coreutils`.
• `Start-Sleep -Seconds 0.5` does NOT error — pwsh silently floors to 0 (the parameter is `[int]`). The bug: a script meant to retry every 500ms instead retries with no delay, hammering the endpoint. Always use `-Milliseconds 500` for sub-second pauses.
• cmd `timeout /t N` without `/nobreak` is interactive — pressing any key aborts. A `for` loop with `timeout` inside `for /l %i in (1,1,10) do timeout /t 60` lets ANY keypress short-circuit the entire batch. Always pair `/t` with `/nobreak` in scripts.
• `timeout /t 5` only works in a real cmd console — under SSH, in Jenkins agents, or in MSYS terminals, `timeout` errors with `ERROR: Input redirection is not supported, exiting the process immediately.` Workaround: `ping -n 6 127.0.0.1 >NUL` (no terminal dependency), or detect interactive shell first.
• Inside `while true; do work; sleep 1; done`, the `sleep` runs as a separate process — Ctrl-C kills the `sleep` and the loop continues to the next iteration's `work`. To make the WHOLE loop interruptible, trap SIGINT: `trap "exit 0" INT; while true; ...`. Same wart applies to pwsh — Ctrl-C in `while ($true) { Start-Sleep 1 }` only kills the current Start-Sleep call.

WSL & PowerShell Core notes

Common tasks using sleep

• Retry a command on failure

  Re-run a command until it succeeds or a retry cap is hit — useful for flaky network calls and CI race conditions.

• Run a command at a specific time

  Schedule a one-shot command to run at a given clock time — `at` on Unix, Task Scheduler on Windows.

• Run a command every N seconds

  Repeat a command on a fixed-interval polling loop — useful for live dashboards, healthcheck-watching, and tail-style log monitoring.

• Run a command with a timeout

  Kill a command if it has not finished within N seconds — the standard hedge against hung network calls, runaway scripts, and tests that should never block forever.

• Wait for a process to finish

  Block until a given process exits — useful for sequencing, dependency-management scripts, and orchestrated shutdowns.