Vista - Re: list env variables

01-03-2007

"Rick" <Rick@discussions.microsoft.com> wrote in message
news:F97D3AF5-93E5-4D24-86A7-D2E326CED85E@microsoft.com...
>Secondly how do you change a variable like
> $HOME, when I try I get "Cannot overwrite variable HOME because it is
> read-only or constant."

Look at using Set-Variable. I believe there is a -force parameter.
Readonly's you can blast over I believe but I'm not sure you do that with a
constant (or perhaps that is reversed). It really frustrating not to have
PoSH installed on this computer. Arrgghh.

--
Keith

01-04-2007

Still confused. If I dir env: I get a list Name / Value ( I truncated the
actual list)
Name
----
HOMEDRIVE
HOMEPATH
HOMESHARE
TEMP
TMP
windir

But if I echo the Name nothing is returned

[C:\Powershell]
# echo $HOMEDRIVE
[C:\Powershell]
# echo $HOMESHARE
[C:\Powershell]
# echo $TEMP
[C:\Powershell]
# echo $HOMEPATH

If I echo $HOME a value is returned and HOME isn't even on the list (nor is
$PROFILE).
So is dir env: really showing PS environment or just The Dos environment?
[C:\Powershell]
# echo $HOME
H:\

Rick

"Keith Hill" wrote:

> "Rick" <Rick@discussions.microsoft.com> wrote in message
> news:F97D3AF5-93E5-4D24-86A7-D2E326CED85E@microsoft.com...
> >Secondly how do you change a variable like
> > $HOME, when I try I get "Cannot overwrite variable HOME because it is
> > read-only or constant."
>
> Look at using Set-Variable. I believe there is a -force parameter.
> Readonly's you can blast over I believe but I'm not sure you do that with a
> constant (or perhaps that is reversed). It really frustrating not to have
> PoSH installed on this computer. Arrgghh.
>
> --
> Keith
>

01-04-2007

Comments in-line

Rick wrote:
> Still confused. If I dir env: I get a list Name / Value ( I truncated the
> actual list)
> Name
> ----
> HOMEDRIVE
> HOMEPATH
> HOMESHARE
> TEMP
> TMP
> windir
>
> But if I echo the Name nothing is returned

You can access names and values of environment variables in a couple of
different ways
1.) get-item env:Environment_Variable_Name(returns
System.Collections.DictionaryEntry containing name/value pair)
e.g.)

Code:

==================================================
[^_^]PS[114]>Get-Item env:HOMEDRIVE

Name                           Value
----                           -----
HOMEDRIVE                      C:

==================================================

2.) using $env variable(returns a VALUE of specified environment
variable)
E.G.)

Code:

==================================================
[^_^]PS[115]>$env:HOMEDRIVE
C:

==================================================

> [C:\Powershell]
> # echo $HOMEDRIVE
> [C:\Powershell]
> # echo $HOMESHARE
> [C:\Powershell]
> # echo $TEMP
> [C:\Powershell]
> # echo $HOMEPATH
>
> If I echo $HOME a value is returned and HOME isn't even on the list (nor is
> $PROFILE).

"$" is used for a variable and unless you have created variables named
"$HOMEDRIVE", "$HOMESHARE", etc,
"echo" will not return anything as the following output shows

Code:

==================================================
# "Strict" option will generate error when you try to access a
non-declared variable
[^_^]PS[122]>Set-PSDebug -Strict
[^_^]PS[123]>echo $HOMEDRIVE
The variable $HOMEDRIVE cannot be retrieved because it has not been set
yet.
At line:1 char:15
+ echo $HOMEDRIVE <<<<
[^_^]PS[124]>echo $HOMESHARE
The variable $HOMESHARE cannot be retrieved because it has not been set
yet.
At line:1 char:15
+ echo $HOMESHARE <<<<
[^_^]PS[125]>echo $TEMP
The variable $TEMP cannot be retrieved because it has not been set yet.
At line:1 char:10
+ echo $TEMP <<<<
[^_^]PS[126]>echo $HOMEPATH
The variable $HOMEPATH cannot be retrieved because it has not been set
yet.
At line:1 char:14
+ echo $HOMEPATH <<<<
[^_^]PS[127]>$TEMP = "some temporary string"
[^_^]PS[128]>echo $TEMP
some temporary string

==================================================

> So is dir env: really showing PS environment or just The Dos environment?
This, i am not sure of...

01-04-2007

"Rick" <Rick@discussions.microsoft.com> wrote in message
news:89021B71-06C3-4613-A0C8-3187FEBC3F25@microsoft.com...
> So is dir env: really showing PS environment or just The Dos environment?

A quick experiment indicates that dir env: shows the enivornment variables
that PowerShell was launched with.

--
Keith

01-04-2007

Thanks All that helps!

"Keith Hill [MVP]" wrote:

> "Rick" <Rick@discussions.microsoft.com> wrote in message
> news:89021B71-06C3-4613-A0C8-3187FEBC3F25@microsoft.com...
> > So is dir env: really showing PS environment or just The Dos environment?
>
> A quick experiment indicates that dir env: shows the enivornment variables
> that PowerShell was launched with.
>
> --
> Keith
>
>
>

01-03-2007	#1 (permalink)
Keith Hill n/a posts	Re: list env variables "Rick" <Rick@discussions.microsoft.com> wrote in message news:F97D3AF5-93E5-4D24-86A7-D2E326CED85E@microsoft.com... >Secondly how do you change a variable like > $HOME, when I try I get "Cannot overwrite variable HOME because it is > read-only or constant." Look at using Set-Variable. I believe there is a -force parameter. Readonly's you can blast over I believe but I'm not sure you do that with a constant (or perhaps that is reversed). It really frustrating not to have PoSH installed on this computer. Arrgghh. -- Keith
My System Specs

01-04-2007	#2 (permalink)
Rick n/a posts	Re: list env variables Still confused. If I dir env: I get a list Name / Value ( I truncated the actual list) Name ---- HOMEDRIVE HOMEPATH HOMESHARE TEMP TMP windir But if I echo the Name nothing is returned [C:\Powershell] # echo $HOMEDRIVE [C:\Powershell] # echo $HOMESHARE [C:\Powershell] # echo $TEMP [C:\Powershell] # echo $HOMEPATH If I echo $HOME a value is returned and HOME isn't even on the list (nor is $PROFILE). So is dir env: really showing PS environment or just The Dos environment? [C:\Powershell] # echo $HOME H:\ Rick "Keith Hill" wrote: > "Rick" <Rick@discussions.microsoft.com> wrote in message > news:F97D3AF5-93E5-4D24-86A7-D2E326CED85E@microsoft.com... > >Secondly how do you change a variable like > > $HOME, when I try I get "Cannot overwrite variable HOME because it is > > read-only or constant." > > Look at using Set-Variable. I believe there is a -force parameter. > Readonly's you can blast over I believe but I'm not sure you do that with a > constant (or perhaps that is reversed). It really frustrating not to have > PoSH installed on this computer. Arrgghh. > > -- > Keith >
My System Specs

01-04-2007	#3 (permalink)
Sung M Kim n/a posts	Re: list env variables Comments in-line Rick wrote: > Still confused. If I dir env: I get a list Name / Value ( I truncated the > actual list) > Name > ---- > HOMEDRIVE > HOMEPATH > HOMESHARE > TEMP > TMP > windir > > But if I echo the Name nothing is returned You can access names and values of environment variables in a couple of different ways 1.) get-item env:Environment_Variable_Name(returns System.Collections.DictionaryEntry containing name/value pair) e.g.) Code: ================================================== [^_^]PS[114]>Get-Item env:HOMEDRIVE Name Value ---- ----- HOMEDRIVE C: ================================================== 2.) using $env variable(returns a VALUE of specified environment variable) E.G.) Code: ================================================== [^_^]PS[115]>$env:HOMEDRIVE C: ================================================== > [C:\Powershell] > # echo $HOMEDRIVE > [C:\Powershell] > # echo $HOMESHARE > [C:\Powershell] > # echo $TEMP > [C:\Powershell] > # echo $HOMEPATH > > If I echo $HOME a value is returned and HOME isn't even on the list (nor is > $PROFILE). "$" is used for a variable and unless you have created variables named "$HOMEDRIVE", "$HOMESHARE", etc, "echo" will not return anything as the following output shows Code: ================================================== # "Strict" option will generate error when you try to access a non-declared variable [^_^]PS[122]>Set-PSDebug -Strict [^_^]PS[123]>echo $HOMEDRIVE The variable $HOMEDRIVE cannot be retrieved because it has not been set yet. At line:1 char:15 + echo $HOMEDRIVE <<<< [^_^]PS[124]>echo $HOMESHARE The variable $HOMESHARE cannot be retrieved because it has not been set yet. At line:1 char:15 + echo $HOMESHARE <<<< [^_^]PS[125]>echo $TEMP The variable $TEMP cannot be retrieved because it has not been set yet. At line:1 char:10 + echo $TEMP <<<< [^_^]PS[126]>echo $HOMEPATH The variable $HOMEPATH cannot be retrieved because it has not been set yet. At line:1 char:14 + echo $HOMEPATH <<<< [^_^]PS[127]>$TEMP = "some temporary string" [^_^]PS[128]>echo $TEMP some temporary string ================================================== > So is dir env: really showing PS environment or just The Dos environment? This, i am not sure of...
My System Specs

01-04-2007	#4 (permalink)
Keith Hill [MVP] n/a posts	Re: list env variables "Rick" <Rick@discussions.microsoft.com> wrote in message news:89021B71-06C3-4613-A0C8-3187FEBC3F25@microsoft.com... > So is dir env: really showing PS environment or just The Dos environment? A quick experiment indicates that dir env: shows the enivornment variables that PowerShell was launched with. -- Keith
My System Specs

01-04-2007	#5 (permalink)
Rick n/a posts	Re: list env variables Thanks All that helps! "Keith Hill [MVP]" wrote: > "Rick" <Rick@discussions.microsoft.com> wrote in message > news:89021B71-06C3-4613-A0C8-3187FEBC3F25@microsoft.com... > > So is dir env: really showing PS environment or just The Dos environment? > > A quick experiment indicates that dir env: shows the enivornment variables > that PowerShell was launched with. > > -- > Keith > > >
My System Specs

Similar Threads
Thread	Forum
math with "GB/MB/KB" in variables fails, without variables works?	PowerShell
$Variables	PowerShell
not using variables	PowerShell