Dear Holger Brunck,

In message 4D92E7B4.9010305@keymile.com you wrote:

I am using env import -t to import environment variables from a textfile.

My simple textfile is: fdt_file=${hostname}/${hostname}.dtb

I import the file with: => tftp 200000 scripts/my_environ.txt => env import -t 200000 ${filesize}

Now when I print the variable I get: => print fdt_file fdt_file=${hostname}/${hostname}.dtb

hostname is defined as: => print hostname hostname=mgcoge

This is perfectly normal. "env export" and "env import" are inverse operations - they export and import the environment data directly, without any conversions (except for the formatting as text lines versus NUL-terminated strings). Neither of these functions performs any variable substitutions - these are done in the command interpreter, i. e. when you run a command in the shell.

Is the usage of ${var} in the textfiles not possible? Or is there a way to solve this problem?

I understand that with "usage of ${var}" you mean variable subsitution - this is indeed not supposed to happen during an "env import".

I don't consider this a problem, though. If you want such substituion, use the defined strings in shell commands.

Actually I consider it more clever to _keep_ the ${hostname} stuff in your variable definitions, as then it is sufficient to change the "hostname" variable to take affect everywhere; if you subsitute the value hard in other variables, you would have to fix all of these (and provide code to do so).

So actually I think this is not a problem, it just points out some inefficient usage of the environment in your setup.

I try to use this textfile for different boards and can therfore not specify hostname in advance in the textfile.

You don't have to. It does not matter when it gets defined (as long as the variables referencing it are not needed before that).

Best regards,

Wolfgang Denk