Ok, so let me see if I understand this...
[EMAIL PROTECTED]:~$ echo $x
[EMAIL PROTECTED]:~$ evalstring=x=something
[EMAIL PROTECTED]:~$ echo $evalstring
x=something
[EMAIL PROTECTED]:~$ $evalstring
bash: x=something: command not found
[EMAIL PROTECTED]:~$ echo $x
[EMAIL PROTECTED]:~$ eval $evalstring
[EMAIL PROTECTED]:~$ echo $x
something
So it's letting you take a string and run it as a command?
Hmm...I guess I would have expect *this* to work:
[EMAIL PROTECTED]:~$ $evalstring
bash: x=something: command not found
Cause *this* works:
[EMAIL PROTECTED]:~$ if="ifconfig eth0"
[EMAIL PROTECTED]:~$ $if
eth0 Link encap:Ethernet HWaddr 00:0f:b0:6e:2b:4a
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
Interrupt:16
Thanks for the tips. I have much yet to learn...
Simón
On Sat, Oct 18, 2008 at 3:00 PM, Rob Ludwick <[EMAIL PROTECTED]> wrote:
> lets say I have a program the echos a bunch of variables, say a
> classpath...
>
> I can't source the file in, I actually have to run it (becuase it might
> be java or C), and it spits out something like:
>
> "CLASSPATH=/blah/blah/blah.jar:/blah/blah/blah2.jar" or whatever a java
> classpath needs to look like.
>
> But running that in a subshell doesn't set it in the current shell.
>
> So I do:
>
> eval `get_java_classpath.exe`
>
> And it sets the CLASSPATH in the current instance of the shell.
>
> Another one is the resize command which spits out variables about the
> size of the shell.
>
> eval `resize` adjusts the variables in the current shell.
>
> --R
>
> On Sat, 2008-10-18 at 14:49 -0400, Simón Ruiz wrote:
>> Rob,
>>
>> I don't get "eval". Was this mentioned on Thursday?
>>
>> [EMAIL PROTECTED]:~$ x=5
>> [EMAIL PROTECTED]:~$ echo $x
>> 5
>> [EMAIL PROTECTED]:~$ eval x=10
>> [EMAIL PROTECTED]:~$ echo $x
>> 10
>>
>> What value does it add?
>>
>> Simón
>>
>> On Sat, Oct 18, 2008 at 2:15 PM, Rob Ludwick <[EMAIL PROTECTED]> wrote:
>> > Here's my quick list of bash shell tricks. I took the approach from
>> > using them more or less in a shell script, but there is some more info
>> > on setting up your bash shell prompt with a link to the color ascii
>> > codes.
>> >
>> > Among the books the Vern suggested, I also highly recommend Linux in a
>> > Nutshell from O'Reilly.
>> >
>> > --R
>> >
>> > _______________________________________________
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>> >
>> >
>>
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>
>
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