> echo "COPY tabelle FROM '/tmp/export_mit_header.tsv' WITH (FORMAT csv, DELIMITER E'\t', HEADER MATCH, NULL '');" | psql -U dbuser -d testdb

oder

> cat /tmp/export_mit_header.tsv | psql -d testdb -U dbuser -c "COPY tabelle FROM STDIN WITH (FORMAT csv, DELIMITER E'\t', HEADER MATCH, NULL '');"