WP-CLI always outputs English because it doesn't support localization. But, because WordPress supports localization, you may see non-English output when performing specific commands.
For instance:
$ wp theme update --all
מעבר למצב תחזוקה...
מוריד עדכונים מ-https://downloads.wordpress.org/theme/hueman.3.3.25.zip...
Using cached file '/home/xxx/.wp-cli/cache/theme/hueman-3.3.25.zip'...
פתיחת עדכון...
התקנת גרסה חדשה...
הסרת הגרסה הקודמת של התבנית...
התבנית עודכנה בהצלחה.
ביטול מצב תחזוקה...
+--------+-------------+-------------+---------+
| name | old_version | new_version | status |
+--------+-------------+-------------+---------+
| hueman | 3.3.24 | 3.3.25 | Updated |
+--------+-------------+-------------+---------+
Success: Updated 1 of 1 themes.
To force WordPress to always output English at the command line, you need to filter the active locale.
Given a force-locale.php
file:
<?php
WP_CLI::add_wp_hook( 'pre_option_WPLANG', function() {
return 'en_US';
});
You can force the locale to en_US
with:
wp --require=force-locale.php
One nice thing about this approach is that you can easily apply it across multiple WP installs using a config file.