SUPPORT MULTIPLE -C AND -F OPTIONS, AND ALLOW MIXING THEM

psql: Support multiple -c and -f options, and allow mixing them.   To support this, we must reconcile some historical anomalies in the behavior of -c. In particular, as a backward-incompatibility, -c no longer implies --no-psqlrc.   Pavel Stehule (code) and Catalin Iacob (documentation). Review by Michael Paquier and myself. Proposed behavior per Tom Lane.

This is really, really great. psql -c/-f support was always “tricky". For example – -c assumed -X (–no-psqlrc), and it support for multiple commands was “tricky".

Consider:

=$ psql -c 'select 1; select 2;' ?column? ---------- 2 (1 row)

So it looks like it ran only 2nd command. In reality it ran both, but returned only last resultset.

Now, we can forget about it – since we can have multiple -c options, we can easily:

=$ psql -c 'select 1' -c 'select 2' ?column? ---------- 1 (1 row)   ?column? ---------- 2 (1 row)

(though putting both selects in single -c, will still yield only result from 2nd select).

Now, with multiple -f, I can, for example:

=$ head *.sql ==> end.sql <== SELECT 'Ending ...', now(); rollback;   ==> start.sql <== BEGIN; SELECT 'Started transaction', now();   ==> work.sql <== SELECT version(), now();   =$ psql -f start.sql -f work.sql -f end.sql BEGIN ?column? | now ---------------------+------------------------------- Started transaction | 2015-12-14 20:09:20.075231+01 (1 row)   version | now -------------------------------------------------------------------------------------------------------------+------------------------------- PostgreSQL 9.6devel on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu 5.2.1-22ubuntu2) 5.2.1 20151010, 64-bit | 2015-12-14 20:09:20.075231+01 (1 row)   ?column? | now ------------+------------------------------- Ending ... | 2015-12-14 20:09:20.075231+01 (1 row)   ROLLBACK

All commands from all 3 files were run, in given order. Of course you can mix and match -c and -f too:

=$ psql -qtA -f start.sql -c "select 'first c'" -f work.sql -c "select 'second c'" -f end.sql BEGIN Started transaction|2015-12-14 20:11:24.628256+01 first c PostgreSQL 9.6devel on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu 5.2.1-22ubuntu2) 5.2.1 20151010, 64-bit|2015-12-14 20:11:24.628256+01 second c Ending ...|2015-12-14 20:11:24.628256+01 ROLLBACK

I, for one, welcome this change whole-heartedly, as it will spare me tricks with printf ‘….; …' | psql.

Thanks a lot