# Create a table
$ hcat -e "create table groups(name string,placeholder string,id int) row format delimited fields terminated by ':' stored as textfile"
OK

# Get the schema for a table
$ hcat -e "desc groups"
OK
name    string  
placeholder     string  
id      int     

# Create another table
$ hcat -e "create table groupids(name string,id int)"
OK

See the HCatalog documentation for information on using the HCatalog command-line application.