For example:
```bash
-root@libreCMC:~# logread | grep 'kern\.warn'
+root@libreCMC:~$ logread | grep 'kern\.warn'
Mon Jan 15 20:22:01 2018 kern.warn kernel: [ 0.000000] No valid device tree found, continuing without
Mon Jan 15 20:22:01 2018 kern.warn kernel: [ 0.000000] Primary instruction cache 64kB, VIPT, 4-way, linesize 32 bytes.
Mon Jan 15 20:22:01 2018 kern.warn kernel: [ 0.000000] Primary data cache 32kB, 4-way, VIPT, cache aliases, linesize 32 bytes
that not all the same regular expressions work for both:
```bash
-root@libreCMC:~# logread -e 'kern\.warn' # and other similar variations
+root@libreCMC:~$ logread -e 'kern\.warn' # and other similar variations
(no output)
```