To start psql , you may want to first be sure that you have either copied the psql binary into a path which is in your system PATH variable (e.g., /usr/bin ), or that you have placed the PostgreSQL binary path (e.g., /usr/local/pgsql/bin ) within your list of paths in your PATH environment variable.

How to set the appropriate PATH variable will depend on your system shell. An example in either bash or ksh might read:

export PATH=$PATH:/usr/local/pgsql/bin

An example in either csh or tcsh might read:

set path=($path /usr/local/pgsql/bin)

Example 4-1. Setting System Path for psql

[user@host user]$ psql
bash: psql: command not found
[user@host user]$ echo $PATH
/bin:/usr/bin:/usr/local/bin:/usr/bin/X11:/usr/X11R6/bin
[user@host user]$ export PATH=$PATH:/usr/local/pgsql/bin
[user@host user]$ psql testdb
Welcome to psql, the PostgreSQL interactive terminal.

Type:  \copyright for distribution terms
       \h for help with SQL commands
       \? for help on internal slash commands
       \g or terminate with semicolon to execute query
       \q to quit
 
testdb=#

Note that Example 4-1 is demonstrated within a Bash shell.

Once you have appropriately set your PATH variable, you should be able to simply type psql at the command line to start up PostgreSQL interactive terminal.

Warning Lifespan of Environment Variables
 

Remember that shell environment variables, in general, are erased after you have logged out! If you wish for your changes to the PATH variable to be persistent on logging in, you will need to be sure to put the appropriate PATH declaration into your shell-specific start-up scripts (e.g., ~/.bash_profile ).