Date: Tue, 6 Aug 2002 10:24:11 -0700 (PDT) From: Patrick Powell <papowell@astart.com> To: FreeBSD-gnats-submit@FreeBSD.org Subject: bin/41384: FreeBSD-STABLE /bin/sh mishandles & && sequences Message-ID: <200208061724.g76HOBc00728@h110.private>
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>Number: 41384
>Category: bin
>Synopsis: FreeBSD-STABLE /bin/sh mishandles & && sequences
>Confidential: no
>Severity: critical
>Priority: high
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Tue Aug 06 10:30:01 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator: Patrick Powell
>Release: FreeBSD 4.6-RELEASE i386
>Organization:
Astart Technologies
>Environment:
System:
i386 FreeBSD-4.6 updated to 4.6-CURRENT using CVS
>Description:
The sequence command & && command is handled differently
in 4.5/4.6 and 4.6 after updating to 4.6 STABLE using CVS.
This breaks a whole slew of shell scripts, including the
startup script in the ports/database/mysqlXXX-server
port.
>How-To-Repeat:
The following script is used for examples:
/tmp/a:
#!/bin/sh
date & && echo DONE
FreeBSD 4.5
h110: {13} % sh -x /tmp/a
+ time
+
+ echo done
done
h114: {5} % uname -a
FreeBSD h114.private 4.6-RELEASE FreeBSD
4.6-RELEASE #0: Thu Jul 11 15:07:12 PDT 2002
papowell@h114.private:/usr/src/sys/compile/TEST i386
h114: {6} % sh -x /tmp/a
+ time
+
+ echo done
done
FreeBSD 4.6
h116: {102} % sh -x /tmp/a
/tmp/a: 1: Syntax error: "&&" unexpected
Note that:
date & echo DONE
will execute correctly:
h116: {104} % sh
# date & echo done
done
# Tue Aug 6 10:19:15 PDT 2002
>Fix:
I suppose that you could violate the POSIX thing and allow
empty commands. I suspect the problem has to do with the
Lexical Structure stuff:
Lexical Structure
The shell reads input in terms of lines from a file and breaks it up into
words at whitespace (blanks and tabs), and at certain sequences of char-
acters called ``operators'', which are special to the shell. There are
two types of operators: control operators and redirection operators
(their meaning is discussed later). The following is a list of valid
operators:
Control operators:
& && ( ) \n
;; ; | ||
You might need to run a check over all the shell scripts that
are using & && sequences... especially in the ports tree.
Patrick
>Release-Note:
>Audit-Trail:
>Unformatted:
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