Hi, On Tue, Jul 04, 2023 at 08:21:10PM +0800, jian he wrote: > Hi. > not sure this is the expected result. > > /home/jian/postgres/pg16_test/bin/psql -d test_dev -p 5455 -c "select $$hello$$" > 2023-07-04 20:15:51.066 CST [1562050] ERROR: trailing junk after > numeric literal at or near "884070h" at character 8 > 2023-07-04 20:15:51.066 CST [1562050] STATEMENT: select 884070hello884070 > ERROR: trailing junk after numeric literal at or near "884070h" > LINE 1: select 884070hello884070 > ^ That's expected, $ is used for variable in the shell and is the pid of the current process. You have to escape any $ in a double-quoted string, or use a single quoted strings.