This isn't easily achieved as OAuth 2.0 and JSON aren't easily handled by Bash. Having said that, here's a basic version that'll give you the data you're looking for. The greps could use some cleanup but then again, interpreting JSON with grep is a really bad idea anyway. This is a perfect example of why the Google API Libraries exist and should be used.
# Store our credentials in our home directory with a file called .
my_creds=~/.`basename $0`
# create your own client id/secret
# https://developers.google.com/identity/protocols/OAuth2InstalledApp#creatingcred
client_id='YOUR OWN CLIENT ID'
client_secret='YOUR OWN SECRET'
if [ -s $my_creds ]; then
# if we already have a token stored, use it
. $my_creds
time_now=`date +%s`
else
scope='https://www.googleapis.com/auth/admin.directory.user.readonly'
# Form the request URL
# https://developers.google.com/identity/protocols/OAuth2InstalledApp#step-2-send-a-request-to-googles-oauth-20-server
auth_url="https://accounts.google.com/o/oauth2/v2/auth?client_id=$client_id&scope=$scope&response_type=code&redirect_uri=urn:ietf:wg:oauth:2.0:oob"
echo "Please go to:"
echo
echo "$auth_url"
echo
echo "after accepting, enter the code you are given:"
read auth_code
# exchange authorization code for access and refresh tokens
# https://developers.google.com/identity/protocols/OAuth2InstalledApp#exchange-authorization-code
auth_result=$(curl -s "https://www.googleapis.com/oauth2/v4/token" \
-H "Content-Type: application/x-www-form-urlencoded" \
-d code=$auth_code \
-d client_id=$client_id \
-d client_secret=$client_secret \
-d redirect_uri=urn:ietf:wg:oauth:2.0:oob \
-d grant_type=authorization_code)
access_token=$(echo -e "$auth_result" | \
grep -Po '"access_token" *: *.*?[^\\]",' | \
awk -F'"' '{ print $4 }')
refresh_token=$(echo -e "$auth_result" | \
grep -Po '"refresh_token" *: *.*?[^\\]",*' | \
awk -F'"' '{ print $4 }')
expires_in=$(echo -e "$auth_result" | \
grep -Po '"expires_in" *: *.*' | \
awk -F' ' '{ print $3 }' | awk -F',' '{ print $1}')
time_now=`date +%s`
expires_at=$((time_now + expires_in - 60))
echo -e "access_token=$access_token\nrefresh_token=$refresh_token\nexpires_at=$expires_at" > $my_creds
fi
# if our access token is expired, use the refresh token to get a new one
# https://developers.google.com/identity/protocols/OAuth2InstalledApp#offline
if [ $time_now -gt $expires_at ]; then
refresh_result=$(curl -s "https://www.googleapis.com/oauth2/v4/token" \
-H "Content-Type: application/x-www-form-urlencoded" \
-d refresh_token=$refresh_token \
-d client_id=$client_id \
-d client_secret=$client_secret \
-d grant_type=refresh_token)
access_token=$(echo -e "$refresh_result" | \
grep -Po '"access_token" *: *.*?[^\\]",' | \
awk -F'"' '{ print $4 }')
expires_in=$(echo -e "$refresh_result" | \
grep -Po '"expires_in" *: *.*' | \
awk -F' ' '{ print $3 }' | awk -F',' '{ print $1 }')
time_now=`date +%s`
expires_at=$(($time_now + $expires_in - 60))
echo -e "access_token=$access_token\nrefresh_token=$refresh_token\nexpires_at=$expires_at" > $my_creds
fi
# call the Directory API list users endpoint, may be multiple pages
# https://developers.google.com/admin-sdk/directory/v1/reference/users/list
while :
do
api_data=$(curl -s --get https://www.googleapis.com/admin/directory/v1/users \
-d customer=my_customer \
-d prettyPrint=true \
`if [ -n "$next_page" ]; then echo "-d pageToken=$next_page"; fi` \
-d maxResults=500 \
-d "fields=users(primaryEmail,creationTime,lastLoginTime),nextPageToken" \
-H "Content-Type: application/json" \
-H "Authorization: Bearer $access_token")
echo -e "$api_data" | grep -v 'nextPageToken'
next_page=$(echo $api_data | \
grep -Po '"nextPageToken" *: *.*?[^\\]"' | \
awk -F'"' '{ print $4 }')
if [ -z "$next_page" ]
then
break
fi
done
