Postgres COPY command escapes new lines and tabs - postgresql

Question

I have a sql function:
CREATE OR REPLACE FUNCTION dump_func()
RETURNS void AS
$BODY$
DECLARE
r record;
loc varchar(100);
BEGIN
for r in (SELECT f.oid as oid, proname, pg_get_functiondef(f.oid) as src
FROM pg_catalog.pg_proc f
INNER JOIN pg_catalog.pg_namespace n ON (f.pronamespace = n.oid)
WHERE n.nspname = 'public') loop
loc = '/Users/raman/Desktop/functions/' || r.proname || '.sql';
raise notice '% - %', r.oid, loc;
raise notice 'func: %', r.src;
EXECUTE format('COPY (
SELECT pg_get_functiondef(f.oid)
FROM pg_catalog.pg_proc f
INNER JOIN pg_catalog.pg_namespace n ON (f.pronamespace = n.oid)
WHERE n.nspname = ''public'' and f.oid=%s
) TO ''%s'' ', r.oid, loc);
end loop;
end
$BODY$
LANGUAGE plpgsql;
which exports each db functions in postgres into a separate file using the COPY command. Everything works except that in the exported sql files new lines and tabs are escaped, for example:
CREATE OR REPLACE FUNCTION public.is_numeric(text)\n RETURNS boolean\n
LANGUAGE plpgsql\n IMMUTABLE\nAS $function$\nDECLARE x
NUMERIC;\nBEGIN\n x = $1::NUMERIC;\n RETURN TRUE;\nEXCEPTION
WHEN others THEN\n RETURN FALSE;\nEND;\n$function$\n
As you can see new lines and tabs are escaped, how to fix that?

Answer 1

Actually, this can be done. Hacky though it is you simply use regexp_split_to_table and split on the \n character. I was just trying to work out the same problem myself. Here's the code I wound up with:
DO $$
DECLARE
v_row record;
v_proname text;
v_sql text;
BEGIN
FOR v_row IN (
SELECT f.proname
FROM pg_catalog.pg_proc AS f
INNER JOIN pg_catalog.pg_namespace AS n ON (f.pronamespace = n.oid)
WHERE n.nspname = 'public' AND f.proisagg = false
) LOOP
SELECT v_row.proname::text INTO v_proname;
EXECUTE FORMAT('COPY (
SELECT regexp_split_to_table(regexp_replace(pg_get_functiondef(oid), ''\t'', '' '', ''g''), ''\n'')
FROM pg_catalog.pg_proc WHERE proname = ''%s'')
TO ''C:\pg\%s.sql'';'
, v_proname, v_proname);
END LOOP;
END $$

Answer 2

Andrew's answer is correct, helped me format it as well.
I came up with a similar function but to print all user defined functions in PSQL. Hope it helps to anyone who needs it:
CREATE OR REPLACE FUNCTION printFunctions(stage VARCHAR, ischema VARCHAR, file_path VARCHAR)
RETURNS VARCHAR AS
$$
DECLARE
func VARCHAR;
file_location TEXT;
BEGIN
FOR func IN SELECT procname FROM listfunctions()
LOOP
SELECT (file_path || '/' || func || '_' || stage || '.sql') INTO file_location;
IF (SELECT regexp_matches(func, '(pldb|plpg)')) IS NULL
THEN
EXECUTE 'COPY ' ||
'(SELECT regexp_split_to_table(regexp_replace(pg_get_functiondef(oid), ''\t'', '' '', ''g''),''\n'') from pg_proc where proname=' ||
'''' || func || '''' ||
' and pronamespace=(select oid from pg_namespace where nspname=' ||
'''' || ischema || ''''
')) TO ' || '''' || file_location || '''';
END IF;
END LOOP;
RETURN stage;
END
$$
LANGUAGE 'plpgsql';
You can call it with:
SELECT * FROM printFunctions('dev', 'public', '/tmp');