While watching a video, I saw the following:
% more tinyUF.txt 10 4 3 3 8 6 5
What is this
% sign before
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That's the shell prompt, or more precisely, it's the shell's primary prompt (there are several). It's the shell's way of saying "go ahead, I'm ready for input now".
% prompt is common in
csh-type shells while
ksh93) ordinarily uses a
$ as the prompt.
The prompt usually changes to
# for the root user since a sufficiently powerful user should be reminded of that power by having an alternate prompt (as the POSIX standard puts it).
The primary prompt in
sh-type shells are determined by the value of the shell variable
Summary of the comments below, with additions:
# character of the root prompt (used by both
csh shells) happens to coincide with the common shell comment character. Copying and pasting a command as root would render the pasted command inoperable, if the shell prompt was also copied. Note that
# was adopted as the root prompt before the shell had a comment convention (reference: email from Doug McIlroy).
rc shells of Plan 9 uses the
; character as the default prompt. A consequence of this is that copying and pasting a command, including the prompt, will still mean that the pasted command is valid (and it will be executed).
A way for enabling one to have a custom, but still copy-pastable, shell prompt, would be to use
: something ;, where
something could be the current directory, hostname or time, for example.