How do I convert this Applescript to Terminal osascript?
There are several ways to accomplish the goal. Here is the method I would use...

In Terminal run the following compound command, e.g.:

f="myscript"; touch "$f"; open -e "$f"; chmod +x "$f"



Note: Change myscript to the name you'd like.


In the new blank TextEdit document that opens, add the following as the first line:

#!/usr/bin/osascript


Then add your AppleScript code under the shebang you just added.

Save the document.

Now to use it in Terminal, e.g.:

./myscript


Or:

/path/to/myscript


Or place in in a directory that is within the defined PATH and then simply use its name, e.g.:

myscript






This method also works; however it's not practical for long scripts:

osascript -e 'tell application "System Preferences" to activate' -e 'tell application "System Preferences"' -e 'reveal anchor "input" of pane id "com.apple.preference.sound"' -e 'end tell' -e 'tell application "System Events" to tell process "System Preferences"' -e 'repeat until exists tab group 1 of window "Sound"' -e 'end repeat' -e 'tell table 1 of scroll area 1 of tab group 1 of window 1' -e 'select (row 1 where value of text field 1 is "Internal Microphone")' -e 'end tell' -e 'end tell' -e 'quit application "System Preferences"'


Please read the manual page for osascript for additional information. In Terminal:

man osascript






On a separate note, if you omit the following line of code you'll not have to see the System Preferences window flash on the screen:

Saved as as script, remove:

tell application "System Preferences" to activate


In the very long drawn out command line, remove:

-e 'tell application "System Preferences" to activate'