cannot start psql (postgres) on mac 10.8.5 - database

Question

Here is what I get when I try to access psql from console. I am using homebrew to run postgres.
atul-new-mac:sites user$ psql
psql: could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/tmp/.s.PGSQL.5432"?
I checked the version by this:
atul-new-mac:sites user$ which psql
/usr/local/bin/psql
Here is the detail from the log file:
atul-new-mac:sites user$ tail -f /usr/local/var/postgres/server.log
ERROR: could not access status of transaction 0
DETAIL: Could not open file "pg_clog/0000": Permission denied.
LOG: received smart shutdown request
LOG: autovacuum launcher shutting down
LOG: shutting down
PANIC: could not open control file "global/pg_control": Permission denied
LOG: checkpointer process (PID 381) was terminated by signal 6: Abort trap
LOG: terminating any other active server processes
LOG: could not open temporary statistics file "pg_stat/global.tmp": Permission denied
LOG: abnormal database system shutdown
This is what I get when I try to start it manually:
atul-new-mac:postgres user$ pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start
pg_ctl: another server might be running; trying to start server anyway
server starting
sh: /usr/local/var/postgres/server.log: Permission denied

Answer 1

Your log tells that your postgresql instance is having trouble with permissions (lines ERROR and PANIC) and reading other extracts you give, you may already have a postgresql instance running.
To check it, just do this command:
ps aux | grep -i "*postgres*"
You should see all postgresql processes running.
Try to stop all thoses processes either by using pg_ctl stop or if nothing happens and the processes are still there, then try to kill them (I presume you're on a development platform, so that should not cause a problem for others)
kill -9 <postgresID>
Then when all the postgresql processes have disappeared, then try to start postgresql. If you're still having a permission problem, use lsof tool to see which process is locking your files.