Passing PostgreSQL psql error messages to unix shell variables - postgresql

Question

I am calling PostgreSQL function from Unix shell script.
Can anyone tell me how do i capture PostgreSQL error messages returned from the function in unix shell variables?
I used the below method but not able to
#!/bin/ksh
function crt_views
{
#Call the POSTGRE pkg which created dynamic views
echo "Calling POSTGRE function FN_CRT_ACTNET_VWS..." >> $LOGFILENAME
pg_msg=`psql --echo-all -U<uname> << EOF
set client_min_messages='NOTICE';
SELECT FUNC_CRT_VWS();
EOF`
}
crt_views
echo "PRINTING - $pg_msg"
In output I'm not seeing the errors returned from the PostgreSQL function. Please help

Answer 1

You need to redirect stderr to stdout, since backtick ing something will get you only stdout.
This is because output that is both from RAISE NOTICE and RAISE EXCEPTION (among other things) is printed to stderr by psql.
Note: I also switched from using backtick ing to dollar-paren style execution. Using the backtick, redirecting stderr in this way doesn't work. (My testing was under sh instead of ksh, but in this case the behavior should be similar, I suspect.)
Also, set -e will fail on error, which may be desireable (depending on your needs).
So, that leads to something like this:
#!/bin/ksh
set -e
function crt_views
{
#Call the Postgres pkg which created dynamic views
echo "Calling Postgres function FN_CRT_ACTNET_VWS..." >> $LOGFILENAME
pg_msg=$(psql --echo-all -U<uname> << EOF
set client_min_messages='NOTICE';
SELECT FUNC_CRT_VWS();
EOF
2>&1)
}
crt_views
echo "PRINTING - $pg_msg"