When alias support is not configured, ash believes that command parameters
that look like dd's "if=/dev/zero" are requests to set a temporary
environment variable whilst dd is running, even though it appears after the
command name. This is caused by the re-use of the checkalias global variable
to indicate when both alias checking and environment variable checking. The
failure to reset this flag is due to the reset action being performed only
inside the feature check CHECK_ASH_ALIAS. Hence ash works as expected when
aliases are configured in, and fails when not.
Example script using 'date' with different settings of TZ:
# TZ=Europe/London
# export TZ
# date
Thu May 30 17:18:49 BST 2002
# TZ=America/New_York date
Thu May 30 12:19:10 EDT 2002
# date
Thu May 30 17:19:12 BST 2002
# date TZ=America/New_York
Thu May 30 12:19:30 EDT 2002 <----- wrong, should be BST time (or error!)
# date
Thu May 30 17:19:35 BST 2002
Attached is a patch against revision 1.52 of ash.c which moves the checks so
that checkalias is updated regardless of whether CONFIG_ASH_ALIAS is set.
With this patch applied, the command shown above which should generate an
error does generate an error.
I have tested this patch with the 'dd' command too and that now works
correctly.
This diff does 2 things:
1) removes an unnecessary function. saves 64 bytes on i386
2) allows you to disable checking of mail (actually, it's now disabled
by default). this would be a nice CML1 option, but for now it's a
#(define|undef) in the C file like the other internal ash options.
this saves an additional 352 bytes if you leave mail disabled.
so that the table implementations of copynode, calcsize, and cmdtxt are
used. Hopefully this will result in wider testing. ;-) If it breaks,
just unset the appropriate defines.
and copynode() table implementations. Commit the fix but keep them disabled
until others check them out. Uncomment "//#define CMDTXT_TABLE",
"//#define CALCSIZE_TABLE", and "//#define COPYNODE_TABLE" to try them out.
Saves over 600 bytes on i386.
math suport, cleaner math syntax error checking, moves redundant signal
string tables (from kill and ash) into libbb and provides a few
cleanups elsewhere.
was written by Aaron Lehmann <aaronl@vitelus.com> for busybox. This
patch makes a few trivial changes to Aaron's code so that it can be
used (in theory) by the other shells as well...
-Erik
