Re: Bug in return code from "bash -c '! command'"

[Chet Ramey]

dworley@pingtel.com wrote:
> Environment:  Bash 3.00.14(1) running on i386 under Fedora Core 3 Linux.
>
> In Bash 3.00, it seems that the return code from bash is not
> duplicated from a command specified by -c if the command starts with
> "!".
>
> To reproduce this, write a script:
>
>         #! /bin/bash
>
>         set -x
>
>         bash --version
>
>         # Create a file baz containing one line containing @.
>         cat >baz <<EOF
>         @
>         EOF
>
>         grep @ baz ; echo $?
>
>         ! grep @ baz ; echo $?
>
>         bash -c "grep @ baz" ; echo $?
>
>         bash -c "! grep @ baz" ; echo $?
>
>         exit
>
> The output it generates is:
>
>         + bash --version
>         GNU bash, version 3.00.14(1)-release (i386-redhat-linux-gnu)
>         Copyright (C) 2004 Free Software Foundation, Inc.
>         + cat
>         + grep @ baz
>         @
>         + echo 0
>         0
>         + grep @ baz
>         @
>         + echo 1
>         1
>         + bash -c 'grep @ baz'
>         @
>         + echo 0
>         0
>         + bash -c '! grep @ baz'
>         @
>         + echo 0
>         0
>         + exit
>
> In the final test, 'bash -c "! grep @ baz"', the command '! grep @
> baz' returns 1, but bash returns 0.

Thanks, fixed.

I've attached the patch.

Chet
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
( ``Discere est Dolere'' -- chet )
                                                Live...Laugh...Love
Chet Ramey, ITS, CWRU    chet@case.edu    http://cnswww.cns.cwru.edu/~chet/

*** ../bash-3.0-patched/builtins/evalstring.c   Tue Jun  3 13:53:12 2003
--- builtins/evalstring.c       Fri Mar 11 16:44:56 2005
***************
*** 234,238 ****
               *   we have parsed the full command (string == '\0') AND
               *   we have a simple command without redirections AND
!              *   the command is not being timed
               * THEN
               *   tell the execution code that we don't need to fork
--- 234,239 ----
               *   we have parsed the full command (string == '\0') AND
               *   we have a simple command without redirections AND
!              *   the command is not being timed AND
!              *   the command's return status is not being inverted
               * THEN
               *   tell the execution code that we don't need to fork
***************
*** 242,246 ****
                  command->type == cm_simple &&
                  !command->redirects && !command->value.Simple->redirects &&
!                 ((command->flags & CMD_TIME_PIPELINE) == 0))
                {
                  command->flags |= CMD_NO_FORK;
--- 243,248 ----
                  command->type == cm_simple &&
                  !command->redirects && !command->value.Simple->redirects &&
!                 ((command->flags & CMD_TIME_PIPELINE) == 0) &&
!                 ((command->flags & CMD_INVERT_RETURN) == 0))
                {
                  command->flags |= CMD_NO_FORK;