Continuing alias substitution after 'command' (due to the final
space in the alias) is inherently broken and doing so by default is
incompatible with the POSIX standard, as aliases may contain
arbitrary shell grammar.
For instance, until the previous commit, the POSIX standard 'times'
command was an alias: times='{ { time;} 2>&1;}' -- and so, of
course, 'command times' gave a syntax error, although this is
a perfectly valid POSIX idiom that must be supported.
'command' is specified by POSIX as a regular builtin, not an alias.
Therefore it should always bypass aliases just as it bypasses
functions to expose standard builtin and external commands.
I can only imagine that the reason for this command='command '
alias was that some standard commands themselves were implemented
as aliases, and POSIX requires that standard commands are
accessible with the 'command' prefix. But implementing standard
commands as aliases is itself inherently broken. It never worked
for 'command times', as shown; and in any case, removing all
aliases with 'unalias -a' should not get rid of standard commands.
Similarly, the default alias nohup='nohup ' is also harmful.
Anyone who really wants to keep this behaviour can just define
these aliases themselves in their script or ~/.kshrc file.
src/cmd/ksh93/data/aliases.c:
- Remove default alias command='command '.
- Remove default alias nohup='nohup '.
src/cmd/ksh93/sh.1
- Remove the above default aliases from the list.
- Mention that the 'command' builtin does not search for aliases.
(cherry picked from commit 5cfe7c4e2015b7445da24983af5008035c4b6e1e)
Allowing redefined macro warnings was not such a good idea, as the
Apple compiler flags redefine the _ast_int8_t macro right on the
command line, producing a warning for every cc invocation.
(cherry picked from commit 929930224f898cb1371471fe554fabb73b31d11f)
Fix BUG_TESTERR1A: POSIX non-compliance of 'test'/'[' exit status
on error. The command now returns status 2 instead of 1 when given
an invalid number or arithmetic expression, e.g.: [ 123 -eq 123x ]
The problem was that the test builtin (b_test()) calls the generic
arithmetic evaluation subsystem (sh/arith.c, sh/streval.c) which
has no awareness of the test builtin. A simple solution would be to
always make the arithmetic subsystem use an exit status > 1 for
arithmetic errors, but globally changing this may cause backwards
compatibility issues. So it's best to change the behaviour of the
'test' builtin only. This requires the arithmetic subsystem to be
aware of whether it was called from the 'test' builtin or not. To
that end, this commit adds a global flag and overrides the
ERROR_exit macro where needed.
src/cmd/ksh93/include/defs.h,
src/cmd/ksh93/sh/defs.c:
- Declare and initialise a global sh_in_test_builtin flag.
- Declare internal function for ERROR_exit override in test.c.
src/cmd/ksh93/bltins/test.c:
- Add override for ERROR_exit macro using a function that checks if
the exit status is at least 2 if the error occurred while running
the test builtin.
- b_test(): Set sh_in_test_builtin flag while running test builtin.
src/cmd/ksh93/sh/arith.c,
src/cmd/ksh93/sh/streval.c:
- Override ERROR_exit macro using function from test.c.
src/cmd/ksh93/tests/bracket.sh:
- Add regression test verifying status > 1 on arith error in test.
(cherry picked from commit 5eeae5eb9fd5ed961a5096764ad11ab870a223a9)
Functions can now be correctly redefined and unset in subshell
environments (such as ( ... ), $(command substitutions), etc).
Before this fix, attempts to do this were silently ignored (!!!),
causing the wrong code (i.e.: the function by the same name from
the parent shell environment) to be executed.
Redefining and unsetting functions within "shared" command
substitutions of the form '${ ...; }' is also fixed.
Prior discussion: https://github.com/att/ast/issues/73
src/cmd/ksh93/sh/parse.c:
- A fix from George Koelher (URL above). He writes:
| The parser can set t->comnamp to the wrong function.
| Suppose that the shell has executed
| foo() { echo WRONG; }
| and is now parsing
| (foo() { echo ok; } && foo)
| The parser was setting t->comnamp to the wrong foo. [This
| fix] doesn't set t->comnamp unless it was a builtin. Now the
| subshell can't call t->comnamp, so it looks for foo and finds
| the ok foo in the subshell's function tree.
src/cmd/ksh93/bltins/typeset.c:
- Unsetting functions in a virtual/non-forked subshell still
doesn't work: nv_open() fails to find the function. To work
around this problem, make 'unset -f' fork the subshell into its
own process with sh_subfork().
- The workaround exposed another bug: if we unset a function in a
subshell tree that overrode a function by the same name in the
main shell, then nv_delete() exposes the function from the main
shell scope. Since 'unset -f' now always forks a subshell, the
fix is to simply walk though troot's parent views and delete any
such zombie functions as well. (Without this, the 4 'more fun'
tests in tests/subshell.sh fail.)
src/cmd/ksh93/sh/subshell.c: sh_subfuntree():
- Fix function (re)definitions and unsetting in "shared" command
substitutions of the form '${ commandlist; }' (i.e.: if
sp->shp->subshare is true). Though internally this is a weird
form of virtual subshell, the manual page says it does not
execute in a subshell (meaning, all changes must survive it), so
a subshell function tree must not be created for these.
src/cmd/ksh93/tests/subshell.sh:
- Add regression tests related to these bugfixes. Test unsetting
and redefining a function in all three forms of virtual subshell.
(cherry picked from commit dde387825ab1bbd9f2eafc5dc38d5fd0bf9c3652)
This fixes three related bugs:
1. Expansions like ${var+set} remained static when used within a
'for', 'while' or 'until' loop; the expansions din't change
along with the state of the variable, so they could not be used
to check whether a variable is set within a loop if the state of
that variable changed in the course of the loop. (BUG_ISSETLOOP)
2. ${IFS+s} always yielded 's', and [[ -v IFS ]] always yielded
true, even if IFS is unset. (BUG_IFSISSET)
3. IFS was incorrectly exempt from '-u' ('-o nounset') checks.
src/cmd/ksh93/sh/macro.c: varsub():
- When getting a node pointer (np) to the parameter to test,
special-case IFS by checking if it has a value and not setting
the pointer if not. The node to IFS always exists, even after
'unset -v IFS', so before this fix it always followed the code
path for a parameter that is set. This fixes BUG_IFSISSET for
${IFS+s} and also fixes set -u (-o nounset) with IFS.
- Before using the 'nv_isnull' macro to check if a regular variable
is set, call nv_optimize() if needed. This fixes BUG_ISSETLOOP.
Idea from Kurtis Rader: https://github.com/att/ast/issues/1090
Of course this only works if SHOPT_OPTIMIZE==1 (the default),
but if not, then this bug is not triggered in the first place.
- Add some comments for future reference.
src/cmd/ksh93/bltins/test.c: test_unop():
- Fix BUG_IFSISSET for [[ -v IFS ]]. The nv_optimize() method
doesn't seem to have any effect here, so the only way that I can
figure out is to special-case IFS, nv_getval()'ing it to check if
IFS has a value in the current scope.
src/cmd/ksh93/tests/variables.sh:
- Add regression tests for checking if a varariable is set within a
loop, within and outside a function with that variable made local
(to check if the scope is honoured). Repeat these tests for a
regular variable and for IFS, for ${foo+set} and [[ -v foo ]].
(cherry picked from commit a2cf79cb98fa3e47eca85d9049d1d831636c9b16)
This allows scripts to check for a nonzero exit status on the
'print', 'printf' and 'echo' builtins and prevent possible infinite
loops if SIGPIPE is ignored.
sfsync() was already returning a negative value on I/O error, so
all we need to do is add a check. The stream buffer will need to be
filled before an I/O error can be detected, but this is the same on
other shells. See manual page: src/lib/libast/man/sfio.3
Ref.: https://github.com/att/ast/issues/1093https://github.com/att/ast/pull/1363
src/cmd/ksh93/bltins/print.c: b_print():
- Make sure an error result from sfsync() is reflected in the
output builtin's exit status (exitval).
- Write an I/O error message (e_io) if the exit status is nonzero.
src/cmd/ksh93/data/msg.c, src/cmd/ksh93/include/io.h:
- Add the e_io[] error message.
src/cmd/ksh93/tests/builtins.sh:
- Add I/O error regression test, checking for the correct error
message and exit status. All three output builtins use the same
b_print() function so we only need to test one.
src/cmd/ksh93/tests/basic.sh,
src/cmd/ksh93/tests/coprocess.sh:
- Redirect stderr on a few 'print' commands to /dev/null; these
now issue an expected I/O error. This does not cause failures.
NEWS, TODO:
- Update.
(cherry picked from commit 9011fa933552e483dab460f7dd1593d64e059d94)
ksh used to redirect standard output by default when no file
descriptor was specified with the rarely used '<>' reading/writing
redirection operator. It now redirects standard input by default,
as POSIX specifies and as all other POSIX shells do. To redirect
standard output for reading and writing, you now need '1<>'.
Ref.: https://github.com/att/ast/issues/75http://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_07_07
(cherry picked from commit 29afc16c47824fc79ed092ae7704c525b1db6a0a)
