How would I get rid of trailing blank line?

"Tena Sakai" <tsakai@gallo.ucsf.edu> writes:

I often use a line like:
psql -tf query.sql mydatabase > query.out

-t option gets rid of the heading and count
report at the bottom. There is a blank line
at the bottom, however. Is there any way to
have psql not give me that blank line?

Doesn't look like it --- the final fputc('\n', fout); seems to be
done unconditionally in all the output formats. I wonder if we should
change that? I'm afraid it might break programs that are used to it :-(

regards, tom lane

Hi Tom,

I am a bit surprised to hear that that '\n'
is there unconditionally. But I am sure
there are more pressing things for you to
work on. It's something I can live with.

Regards,

Tena Sakai
tsakai@gallo.ucsf.edu

-----Original Message-----
From: Tom Lane [mailto:tgl@sss.pgh.pa.us]
Sent: Thu 4/2/2009 4:01 PM
To: Tena Sakai
Cc: pgsql-sql@postgresql.org; pgsql-hackers@postgresql.org
Subject: Re: [SQL] How would I get rid of trailing blank line?

"Tena Sakai" <tsakai@gallo.ucsf.edu> writes:

I often use a line like:
psql -tf query.sql mydatabase > query.out

-t option gets rid of the heading and count
report at the bottom. There is a blank line
at the bottom, however. Is there any way to
have psql not give me that blank line?

Doesn't look like it --- the final fputc('\n', fout); seems to be
done unconditionally in all the output formats. I wonder if we should
change that? I'm afraid it might break programs that are used to it :-(

regards, tom lane

Tom Lane wrote:

"Tena Sakai" <tsakai@gallo.ucsf.edu> writes:

I often use a line like:
psql -tf query.sql mydatabase > query.out

-t option gets rid of the heading and count
report at the bottom. There is a blank line
at the bottom, however. Is there any way to
have psql not give me that blank line?

Doesn't look like it --- the final fputc('\n', fout); seems to be
done unconditionally in all the output formats. I wonder if we should
change that? I'm afraid it might break programs that are used to it :-(

Right. There's a simple pipeline way to get rid of it:

psql -t -f query.sql | sed -e '$d' > query.out

cheers

andrew

On Thu, Apr 2, 2009 at 3:33 PM, Tena Sakai <tsakai@gallo.ucsf.edu> wrote:

Hi Everybody,

I am using postgres 8.3.4 on linux.
I often use a line like:
  psql -tf query.sql mydatabase > query.out

-t option gets rid of the heading and count
report at the bottom.  There is a blank line
at the bottom, however.  Is there any way to
have psql not give me that blank line?

Tired of those blank lines in your text files? Grep them away:

psql -tf query.sql mydatabase | grep -v "^$" > query.out

Thank you for your help.

Regards,

Tena Sakai
tsakai@gallo.ucsf.edu

--
When fascism comes to America, it will be the intolerant selling it as
diversity.

Hi Andrew,

Right. There's a simple pipeline way to get rid of it:
psql -t -f query.sql | sed -e '$d' > query.out

Hi Scott,

Tired of those blank lines in your text files? Grep them away:
psql -tf query.sql mydatabase | grep -v "^$" > query.out

Thank you Both.

Regards,

Tena Sakai
tsakai@gallo.ucsf.edu

-----Original Message-----
From: Andrew Dunstan [mailto:andrew@dunslane.net]
Sent: Thu 4/2/2009 6:34 PM
To: Tom Lane
Cc: Tena Sakai; pgsql-sql@postgresql.org; pgsql-hackers@postgresql.org
Subject: Re: [HACKERS] [SQL] How would I get rid of trailing blank line?

Tom Lane wrote:

"Tena Sakai" <tsakai@gallo.ucsf.edu> writes:

I often use a line like:
psql -tf query.sql mydatabase > query.out

-t option gets rid of the heading and count
report at the bottom. There is a blank line
at the bottom, however. Is there any way to
have psql not give me that blank line?

Doesn't look like it --- the final fputc('\n', fout); seems to be
done unconditionally in all the output formats. I wonder if we should
change that? I'm afraid it might break programs that are used to it :-(

Right. There's a simple pipeline way to get rid of it:

psql -t -f query.sql | sed -e '$d' > query.out

cheers

andrew

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Hash: RIPEMD160

report at the bottom. There is a blank line
at the bottom, however. Is there any way to
have psql not give me that blank line?

Now that my presenation on psql is over :), I'll share my solution:

psql -AX -qt -c "SELECT ..." | perl -pe 's/^\n// if $.<2'

This strips a newline from the first line only of the output, and
only if the line consists of nothing else. Highly recommended
for cron.

- --
Greg Sabino Mullane greg@turnstep.com
End Point Corporation
PGP Key: 0x14964AC8 200904052221
http://biglumber.com/x/web?pk=2529DF6AB8F79407E94445B4BC9B906714964AC8
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On 2009-04-02, Tena Sakai <tsakai@gallo.ucsf.edu> wrote:

I am using postgres 8.3.4 on linux.
I often use a line like:
psql -tf query.sql mydatabase > query.out

-t option gets rid of the heading and count
report at the bottom. There is a blank line
at the bottom, however. Is there any way to
have psql not give me that blank line?

I ask postgres to format it for me instead of relying on psql

psql db_name -c "copy (select * from foo ) to stdout;"

this gives me postgres style tab separated values, but I can
have CSV (or any otther format COPY can do) if I want.
I usually use a more complex subquery with a list of columns and
expressions, where, order by clauses, etc... )

I use this in a script that pulls data from one database and inserts
in into another.

Requires postgres 8.2 or later

The sed -e '$d' is nice but it has a downside - it will mask the return code
from psql in the case when there is an error

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