bug-bash
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Aliases in subbshell does not work as expected


From: Jon Seymour
Subject: Re: Aliases in subbshell does not work as expected
Date: Mon, 12 Jan 2009 00:00:25 +1100

G'day,

This working as documented.

The relevant part of the manual is, I think:

"Bash always reads at  least  one  complete  line  of  input  before
executing  any  of  the  commands  on  that  line.  Aliases are
expanded when a command is read, not when it is  executed."

If aaa is not already defined, the actual behaviour is:

$ alias aaa='echo aaa'; ( alias aaa='echo bbb'; aaa ; )
-bash: aaa: command not found

Which is consistent with the manual page. If aaa is already defined, then

$ alias aaa='echo aaa'; ( alias aaa='echo bbb'; aaa ; )
aaa

which is what you observed.

Use unalias aaa and then you will get:

$ alias aaa='echo aaa'; ( alias aaa='echo bbb'; aaa ; )
-bash: aaa: command not found

jon.

On 11/01/2009, at 23:18, Коренберг Марк
<address@hidden> wrote:

> Configuration Information [Automatically generated, do not change]:
> Machine: i486
> OS: linux-gnu
> Compiler: gcc
> Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='i486' -
> DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='i486-pc-linux-gnu' -
> DCONF_VENDOR='pc' -DLOCALED $uname output: Linux mmarkk-desktop
> 2.6.27-11-generic #1 SMP Thu Jan 8 08:38:33 UTC 2009 i686 GNU/Linux
> Machine Type: i486-pc-linux-gnu
>
> Bash Version: 3.2
> Patch Level: 39
> Release Status: release
>
> Description:
>       See Repeat-by section.
>
> Repeat-By:
>       alias aaa='echo aaa'; ( alias aaa='echo bbb'; aaa ; )
>       Will print 'aaa' instead of 'bbb' as I expect.
>
>

reply via email to

[Prev in Thread] Current Thread [Next in Thread]