I set some environment variables in a terminal, and then run my script. How can I pull in the variables in the script? I need to know their values. Simply referring to them as
$MY_VAR1 doesn't work; it is empty.
If the variables are truly environment variables (i.e., they've been exported with
export) in the environment that invokes your script, then they would be available in your script. That they aren't suggests that you haven't exported them, or that you run the script from an environment where they simply don't exist even as shell variables.
$ cat script.sh #!/bin/sh echo "$hello"
$ sh script.sh
(one empty line of output since
hello doesn't exist anywhere)
$ hello="hi there" $ sh script.sh
(still only an empty line as output as
hello is only a shell variable, not an environment variable)
$ export hello $ sh script.sh hi there
Alternatively, to set the environment variable just for this script and not in the calling environment:
$ hello="sorry, I'm busy" sh script.sh sorry, I'm busy
$ env hello="this works too" sh script.sh this works too
You need to ensure you export the environment variables you want to have access to in your script before you invoke the script. IE:
Unix> export MY_TEMP=/tmp Unix> some_script.sh
Now some_script.sh would have access to $MY_TEMP -- when you invoke a shell script, you get a new environment, with only exported variables, unless you "source" it by preceeding the script command with a period (".") and a space, then your script name:
Unix> . some_script.sh # runs in current environment
Debugging tip: Include near the top of your script the
set command to see what variables your script can see.