askenv command

Synopsis

askenv name [message] [size]

Description

Display message and get environment variable name of max size characters from stdin.

name

name of the environment variable

message

message is displayed while the command waits for the value to be entered from stdin.if no message is specified,a default message “Please enter name:” will be displayed.

size

maximum number of characters that will be stored in environment variable name.this is in decimal number format (unlike in other commands where size values are in hexa-decimal). Default value of size is 1023 (CONFIG_SYS_CBSIZE - 1).

Example

Value of a environment variable env1 without message and size parameters:

=> askenv env1;echo $?
Please enter 'env1': val1
0
=> printenv env1
env1=val1

Value of a environment variable env2 with message and size parameters:

=> askenv env2 Please type-in a value for env2: 10;echo $?
Please type-in a value for env2: 1234567890123
0
=> printenv env2
env2=1234567890

Value of a environment variable env3 with size parameter only:

=> askenv env3 10;echo $?
Please enter 'env3': val3
0
=> printenv env3
env3=val3

Return Value of askenv command, when used without any other arguments:

=> askenv;echo $?
askenv - get environment variables from stdin

Usage:
askenv name [message] [size]
    - display 'message' and get environment variable 'name' from stdin (max 'size' chars)
1

Configuration

The askenv command is only available if CMD_ASKENV=y

Return value

The return value $? is set to 0 (true). If no other arguments are specified (along with askenv), it is set to 1 (false).