timestamp

timestamp

Prefix each line of stdout and stderr with elapsed seconds since the command started ([seconds.mmm]). Useful for profiling commands that do not log timing themselves, such as podman build, minikube start, or long CI steps.

Build

make

The binary is timestamp in this directory (gitignored).

Test

make test

Builds timestamp first, then runs the tests.

Usage

./timestamp <command> [arguments...]

Example:

$ ./timestamp bash -c 'echo first; echo second; sleep 1.234; echo last'
[    0.000] bash -c "echo first; echo second; sleep 1.234; echo last"
[    0.020] first
[    0.020] second
[    1.259] last

The first line is printed at 0.000 with the command being timed. Without it, the first timestamp appears only when the command prints output, hiding startup time.

Exit status matches the wrapped command.

Notes

• Timestamps are per line (\n). Output without a newline is stamped when the process exits. Elapsed time is measured from when the child process starts, with millisecond precision.

• The child uses pipes, not a TTY, so programs may buffer output. Timestamps reflect when this tool reads a line, not when the child wrote it.

• Stdin is passed through so the command can consume stdin. When a command stops to wait for input, a plain wall-clock timer includes the wait; with timestamp you can see exactly when output resumes after the prompt.

• Arguments are quoted when needed so the line is copy-pasteable in a shell.