Hi, Not quite right there ... You can preceed a command with an assignment, and the assigned variable is then put into the environment of the command that is run. Thus the command "echo" is run with an environment variable AAAA with the value aaaa. However, this does not change the AAAA shell variable (which is currently empty) so the echo prints a blank (it's empty argument) and ignores the AAAA in it's environment.
This syntax is useful for setting environment variables for one command invocation only. They are not saved. I hope this fully explains what is going on. /John Vincent.
From: "Elfyn McBratney" <[EMAIL PROTECTED]>
To: "Huang." <[EMAIL PROTECTED]>
CC: <[EMAIL PROTECTED]>
Subject: Re: About ENV?
Date: Fri, 18 Oct 2002 10:03:05 +0100
Its just bash topology... If your setting a variable and calling a command
after it, or doing anything on one line with another expression after it you
need to end the expression before starting another one, which is done with
the semi-colon ';'.
On the first one:
$ AAAA=aaa echo $AAAA
AAAA now looks like "aaa echo " unless AAAA already exists, and if so would
contain the variable contents after the "echo " bit...
Elfyn
----- Original Message -----
From: Huang. <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Friday, October 18, 2002 7:31 AM
Subject: About ENV?
> Why env in cygwin work like these:
>
> $ AAAA=aaa echo $AAAA
>
>
> $ AAAA=aaa; echo $AAAA
> aaa
>
> $ echo $AAAA
> aaa
>
>
> Maybe it not correct?
>
> Thanks.
>
>
>
>
>
>
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