* [9fans] environment variables bevanving weird
@ 2012-06-08 23:02 Friedrich Psiorz
2012-06-08 23:13 ` vrtra
2012-06-08 23:13 ` Federico Benavento
0 siblings, 2 replies; 3+ messages in thread
From: Friedrich Psiorz @ 2012-06-08 23:02 UTC (permalink / raw)
To: 9fans
hi! I'm new to Plan 9 and I don't understand this behavior:
I wrote a program that basically just does
putenv("foo", "bar");
After running it,
echo $foo
prints just an empty line, while
cat /env/foo
prints bar. Can anyone explain?
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [9fans] environment variables bevanving weird
2012-06-08 23:02 [9fans] environment variables bevanving weird Friedrich Psiorz
@ 2012-06-08 23:13 ` vrtra
2012-06-08 23:13 ` Federico Benavento
1 sibling, 0 replies; 3+ messages in thread
From: vrtra @ 2012-06-08 23:13 UTC (permalink / raw)
To: Fans of the OS Plan 9 from Bell Labs
> hi! I'm new to Plan 9 and I don't understand this behavior:
>
> I wrote a program that basically just does
> putenv("foo", "bar");
>
> After running it,
> echo $foo
> prints just an empty line, while
> cat /env/foo
> prints bar. Can anyone explain?
I asked a somewhat same question a month back
http://9fans.net/archive/2012/05/281
The reason seems to be that while creating a variable foo
in rc is immediately reflected to /env/foo, the reverse is
not true. That is, creating a new file under /env/baz does
not update the current rc instance with a new variable $baz
So in this case, putenv is actually writing to /env/foo,
and it would be visible only if you start a new rc
instance. (or just read from the same file.)
v
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [9fans] environment variables bevanving weird
2012-06-08 23:02 [9fans] environment variables bevanving weird Friedrich Psiorz
2012-06-08 23:13 ` vrtra
@ 2012-06-08 23:13 ` Federico Benavento
1 sibling, 0 replies; 3+ messages in thread
From: Federico Benavento @ 2012-06-08 23:13 UTC (permalink / raw)
To: Fans of the OS Plan 9 from Bell Labs
see env(3), basically the rfork flags affect it. check the man page.
On Jun 8, 2012, at 8:02 PM, Friedrich Psiorz wrote:
> hi! I'm new to Plan 9 and I don't understand this behavior:
>
> I wrote a program that basically just does
> putenv("foo", "bar");
>
> After running it,
> echo $foo
> prints just an empty line, while
> cat /env/foo
> prints bar. Can anyone explain?
>
---
Federico Benavento
benavento@gmail.com
^ permalink raw reply [flat|nested] 3+ messages in thread
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2012-06-08 23:02 [9fans] environment variables bevanving weird Friedrich Psiorz
2012-06-08 23:13 ` vrtra
2012-06-08 23:13 ` Federico Benavento
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