Question

How can I escape a probable hyphen in a comand line like the following:

$ for i in db1 db2 db1-db2; do su - postgres -c "psql -c \"alter database \"$i\" with connection limit = 0;\""; done

ALTER DATABASE


ALTER DATABASE ERROR:  syntax error at or near "-" at character 19 LINE 1: alter database db1-db2 with connection limit = 0;
                      ^

Answer 1

The “quoting hell” can be somehow alleviated by providing the SQL in standard input as a here-string.

In your case I think this should do the job:

for i in db1 db2 db1-db2; do su - postgres -c "(psql <<EOF
alter database \"$i\" with connection limit = 0;
EOF
)"; done