9(1) 9(1)
NAME
9, 9.rc, u, u.rc - run Plan 9 or Unix commands
SYNOPSIS
9 cmd [ args ... ]
. 9 (from sh(1))
9.rc cmd [ args ... ]
. 9.rc (from rc(1))
u cmd [ args ... ]
. u (from sh(1))
u.rc cmd [ args ... ]
. u.rc (from rc(1))
DESCRIPTION
Because Plan 9 supplies commands with the same name as but
different behavior than many basic Unix system commands
(e.g., grep, sed, mkdir, rm), it is not recommended to run
with the Plan 9 bin directory ahead of the system directo-
ries.
9 is a shell script that sets up a Plan 9 environment and
runs cmd . It sets $PLAN9 if necessary and adds $PLAN9/bin
to the beginning of $PATH before running cmd.
If run with no arguments, 9 does not do anything, so it can
be invoked from sh-style shells using . 9 in order to make
the current shell start running in the Plan 9 environment.
9.rc is the same as 9 but written for use by the shell
rc(1).
U and u.rc are the inverse of 9 and 9.rc: they move
$PLAN9/bin to the end of the path.
EXAMPLES
Search for greek in the password file:
$ 9 grep '[α-ζ]' /etc/passwd
Start an rc(1) with the Plan 9 commands in the path before
the system commands, and then run the Unix ls:
$ 9 rc
Page 1 Plan 9 (printed 11/5/25)
9(1) 9(1)
% u ls
SOURCE
/usr/local/plan9/bin/9
/usr/local/plan9/bin/9.rc
/usr/local/plan9/bin/u
/usr/local/plan9/bin/u.rc
SEE ALSO
intro(1)
BUGS
Some shell configurations (notably, oh-my-zsh) define 9 as
an alias for cd -9, which makes the 9 command described here
inaccessible. In such shells, it is necessary to unalias 9
in your initialization scripts.
Page 2 Plan 9 (printed 11/5/25)