cd.1

早期freebsd实现

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.\"     @(#)cd.1	8.1 (Berkeley) 6/5/93
.\"
.Dd June 5, 1993
.Dt CD 1
.Os BSD 4
.Sh NAME
.Nm cd
.Nd change working directory
.Sh SYNOPSIS
.Nm cd
.Ar directory
.Sh DESCRIPTION
.Ar Directory
is an absolute or relative pathname which becomes the new working
directory.
The interpretation of a relative pathname by cd depends on the CDPATH
environment variable (see below).
.Sh ENVIRONMENT
The following environment variables affect the execution of cd:
.Pp
.Bl -tag -width indent
.It Ev CDPATH
If the
.Ar directory
operand does not begin with a slash (/) character, and the first
component is not dot (.) or dot-dot (..),
.Nm cd
searches for the directory relative to each directory named in the
.Ev CDPATH
variable, in the order listed.
The new working directory is set to the first matching directory found.
An empty string in place of a directory pathname represents the current
directory.
If the new working directory was derived from
.Ev CDPATH ,
it will be printed to the standard output.
.It Ev HOME
If
.Nm cd
is invoked without arguments and the
.Ev HOME
environment variable exists and contains a directory name, that directory
becomes the new working directory.
.El
.Pp
See
.Xr csh 1
for more information on environment variables.
.Pp
The
.Nm cd
utility exits 0 on success, and >0 if an error occurs.
.Sh SEE ALSO
.Xr csh 1 ,
.Xr pwd 1 ,
.Xr sh 1 ,
.Xr chdir 2
.Sh STANDARDS
The
.Nm cd
command is expected to be
.St -p1003.2
compatible.