Unix 'file' command has a -0 option to output a null character after a filename. This is supposedly good for using with 'cut'.
From man file
:
-0, --print0
Output a null character ‘\0’ after the end of the filename. Nice
to cut(1) the output. This does not affect the separator which is
still printed.
(Note, on my Linux, the '-F' separator is NOT printed - which makes more sense to me.)
How can you use 'cut' to extract a filename from output of 'file'?
This is what I want to do:
find . "*" -type f | file -n0iNf - | cut -d<null> -f1
where <null>
is the NUL character.
Well, that is what I am trying to do, what I want to do is get all file names from a directory tree that have a particular MIME type. I use a grep (not shown).
I want to handle all legal file names and not get stuck on file names with colons, for example, in their name. Hence, NUL would be excellent.
I guess non-cut solutions are fine too, but I hate to give up on a simple idea.
Just specify an empty delimiter:
cut -d '' -f1
Notes:
-d
and the ''
is important, so that the -d
and the empty string get passed as separate arguments; if you write -d''
, then that will get passed as just -d
, and then cut
will think you're trying to use -f1
as the delimiter, which it will complain about, with an error message that "the delimiter must be a single character".cut
doesn't support using the null character as the delimiter. Fortunately, other answers on this page provide solutions that should work on such systems.