dated

Add a timestamp to every line of a stream:

... | dated [-f format]

Description

dated copies standard input to standard output, prepending the date and time to every line.

The -f option changes the prefix format string to format, which is passed to strftime(3). The default is "%x %X ": the local date notation, a space, the local time notation, and another space.

Note: there is no way to get subsecond precision, a limitation of strftime(3).

Examples

Watch a file with tail(1) and see when lines were added:

$ tail -f test.txt | dated
11/07/18 21:28:31 Hello
11/07/18 21:28:40 World!

Change the output format:

$ tail -f test.txt | dated -f "[%H:%M] "
[21:32] Hello
[21:33] World!

Running

Should work on any Unix, including Linux and macOS.

Mac users can install from my Homebrew tap

brew install sjmulder/tap/dated

To compile, install and uninstal from source:

make
make install   [DESTDIR=] [PREFIX=/usr/local] [MANPREFIX=PREFIX/man]
make uninstall [DESTDIR=] [PREFIX=/usr/local] [MANPREFIX=PREFIX/man]

Authors

Sijmen J. Mulder (ik@sjmulder.nl)