псевдофайловая система информации о процессе (process information pseudo-filesystem)
Примечание (Note)
Many files contain strings (e.g., the environment and command
line) that are in the internal format, with subfields terminated
by null bytes ('\0'). When inspecting such files, you may find
that the results are more readable if you use a command of the
following form to display them:
$ cat
file | tr '\000' '\n'
This manual page is incomplete, possibly inaccurate, and is the
kind of thing that needs to be updated very often.