Date: Sat, 21 Dec 2002 13:33:01 +0100 (CET) From: Jens Schweikhardt <schweikh@FreeBSD.org> To: FreeBSD-gnats-submit@FreeBSD.org Subject: standards/46441: /bin/sh does not do parameter expansion in PS1, PS2, PS4 Message-ID: <200212211233.gBLCX1eX045120@hal9000.schweikhardt.net>
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>Number: 46441
>Category: standards
>Synopsis: /bin/sh does not do parameter expansion in PS1, PS2, PS4
>Confidential: no
>Severity: non-critical
>Priority: low
>Responsible: freebsd-standards
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Sat Dec 21 04:40:01 PST 2002
>Closed-Date:
>Last-Modified:
>Originator: Jens Schweikhardt
>Release: FreeBSD 5.0-CURRENT i386
>Organization:
Digital Details
>Environment:
System: FreeBSD hal9000.schweikhardt.net 5.0-CURRENT FreeBSD 5.0-CURRENT #1: Fri Nov 29 11:10:37 CET 2002 toor@hal9000.schweikhardt.net:/usr/obj/src/current/sys/HAL9000 i386
>Description:
If our /bin/sh is intended to support the SUSv3 User Portability
(UP) option, it must do parameter expansion in PS[124]. If not,
consider this PR null and void, even where prohibited. Quoting
IEEE Std 1003.1-2001:
PS1
Each time an interactive shell is ready to read a command, the value of
this variable shall be subjected to parameter expansion and written to
standard error. The default value shall be "$ " . For users who have
specific additional implementation-defined privileges, the default may
be another, implementation-defined value. The shell shall replace each
instance of the character '!' in PS1 with the history file number of
the next command to be typed. Escaping the '!' with another '!' (that
is, "!!" ) shall place the literal character '!' in the prompt. This
volume of IEEE Std 1003.1-2001 specifies the effects of the variable
only for systems supporting the User Portability Utilities option.
PS2
Each time the user enters a <newline> prior to completing a command
line in an interactive shell, the value of this variable shall be
subjected to parameter expansion and written to standard error. The
default value is "> " . This volume of IEEE Std 1003.1-2001 specifies
the effects of the variable only for systems supporting the User
Portability Utilities option.
PS4
When an execution trace ( set -x) is being performed in an interactive
shell, before each line in the execution trace, the value of this
variable shall be subjected to parameter expansion and written to
standard error. The default value is "+ " . This volume of IEEE Std
1003.1-2001 specifies the effects of the variable only for systems
supporting the User Portability Utilities option.
PWD
Set by the shell to be an absolute pathname of the current working
directory, containing no components of type symbolic link, no
components that are dot, and no components that are dot-dot when the
shell is initialized. If an application sets or unsets the value of
PWD, the behaviors of the cd and pwd utilities are unspecified.
>How-To-Repeat:
$ /bin/sh
$ PS1='$PWD >'
$PWD >cd /tmp <- should expand $PWD
$PWD >PS2='$PWD more:'
$PWD >foo ()
$PWD more:{
$PWD more:}
$PWD >PS4='$PWD -x : '
$PWD >set -x
$PWD >foo
+ foo <- PS4 seems hard coded to "+ "
>Fix:
>Release-Note:
>Audit-Trail:
>Unformatted:
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