Thread: psql ctrl+f skips displaying of one record and displays skipping one line
Hi,
One observation when we execute a select query having results more than the screen space available and press ctrl+f to display the remaining records, one of the record was not displayed and the message "...skipping one line" was displayed.
I'm not sure if this is intentional behaviour.
Steps for the same:
postgres=# create table psqltest as select generate_series(1,50);
SELECT 50
postgres=# select * from psqltest;
generate_series
-----------------
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
...skipping one line
47
48
49
50
(50 rows)
Is this intended?
Re: psql ctrl+f skips displaying of one record and displays skippingone line
From
Thomas Munro
Date:
On Wed, Jul 17, 2019 at 4:07 PM vignesh C <vignesh21@gmail.com> wrote: > One observation when we execute a select query having results more than the screen space available and press ctrl+f todisplay the remaining records, one of the record was not displayed and the message "...skipping one line" was displayed. > > I'm not sure if this is intentional behaviour. Pretty sure this is coming from your system's pager. You can see the same thing when you run this on a RHEL box: seq 1 10000 | more It skips a line each time you press ^F. Doesn't happen on FreeBSD or macOS though. -- Thomas Munro https://enterprisedb.com
Thomas Munro <thomas.munro@gmail.com> writes:
> Pretty sure this is coming from your system's pager. You can see the
> same thing when you run this on a RHEL box:
> seq 1 10000 | more
> It skips a line each time you press ^F.
Yeah, duplicated on RHEL6. It seems to behave the same as the documented
"s" command. Not sure why it's not listed in the man page --- though
there's a disclaimer saying that the man page was basically
reverse-engineered, so maybe they just missed this synonym.
> Doesn't happen on FreeBSD or macOS though.
macOS's "more" is actually "less", so it's not surprising it's not
bug-compatible. Can't say about FreeBSD.
regards, tom lane
I'm able to get the same behaviour in centos as well.
Should we do anything to handle this in Postgres or any documentation required?
On Wed, Jul 17, 2019 at 10:05 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
Thomas Munro <thomas.munro@gmail.com> writes:
> Pretty sure this is coming from your system's pager. You can see the
> same thing when you run this on a RHEL box:
> seq 1 10000 | more
> It skips a line each time you press ^F.
Yeah, duplicated on RHEL6. It seems to behave the same as the documented
"s" command. Not sure why it's not listed in the man page --- though
there's a disclaimer saying that the man page was basically
reverse-engineered, so maybe they just missed this synonym.
> Doesn't happen on FreeBSD or macOS though.
macOS's "more" is actually "less", so it's not surprising it's not
bug-compatible. Can't say about FreeBSD.
regards, tom lane
Regards,
vignesh
Have a nice day
vignesh
Have a nice day
vignesh C <vignesh21@gmail.com> writes:
> I'm able to get the same behaviour in centos as well.
> Should we do anything to handle this in Postgres or any documentation
> required?
It already is documented:
PSQL_PAGER
PAGER
If a query's results do not fit on the screen, they are piped
through this command. Typical values are more or less. Use of the
pager can be disabled by setting PSQL_PAGER or PAGER to an empty
string, or by adjusting the pager-related options of the \pset
command. These variables are examined in the order listed; the
first that is set is used. If none of them is set, the default is
to use more on most platforms, but less on Cygwin.
We're certainly not going to copy four or five different versions
of the "more" and "less" man pages into psql's man page, if that's
what you're suggesting. Nor is it our job to point out shortcomings
in some versions of those man pages.
regards, tom lane
Thanks Tom.
That sounds good to me.
On Wed, Jul 17, 2019 at 10:17 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
vignesh C <vignesh21@gmail.com> writes:
> I'm able to get the same behaviour in centos as well.
> Should we do anything to handle this in Postgres or any documentation
> required?
It already is documented:
PSQL_PAGER
PAGER
If a query's results do not fit on the screen, they are piped
through this command. Typical values are more or less. Use of the
pager can be disabled by setting PSQL_PAGER or PAGER to an empty
string, or by adjusting the pager-related options of the \pset
command. These variables are examined in the order listed; the
first that is set is used. If none of them is set, the default is
to use more on most platforms, but less on Cygwin.
We're certainly not going to copy four or five different versions
of the "more" and "less" man pages into psql's man page, if that's
what you're suggesting. Nor is it our job to point out shortcomings
in some versions of those man pages.
regards, tom lane
Regards,
vignesh
Have a nice day
vignesh
Have a nice day