If set, the pager will not be used unless this many lines are to be
displayed, even if that is more than the screen depth. Default is zero,
meaning it's disabled.
There is probably more work to be done in giving the user control over
when the pager is used, particularly when wide output forces use of the
pager regardless of how many lines there are, but this is a start.
GNU readline defines the return value of write_history() as "zero if OK,
else an errno code". libedit's version of that function used to have a
different definition (to wit, "-1 if error, else the number of lines
written to the file"). We tried to work around that by checking whether
errno had become nonzero, but this method has never been kosher according
to the published API of either library. It's reportedly completely broken
in recent Ubuntu releases: psql bleats about "No such file or directory"
when saving ~/.psql_history, even though the write worked fine.
However, libedit has been following the readline definition since somewhere
around 2006, so it seems all right to finally break compatibility with
ancient libedit releases and trust that the return value is what readline
specifies. (I'm not sure when the various Linux distributions incorporated
this fix, but I did find that OS X has been shipping fixed versions since
10.5/Leopard.)
If anyone is still using such an ancient libedit, they will find that psql
complains it can't write ~/.psql_history at exit, even when the file was
written correctly. This is no worse than the behavior we're fixing for
current releases.
Back-patch to all supported branches.
psql's \s (print command history) doesn't work at all with recent libedit
versions when printing to the terminal, because libedit tries to do an
fchmod() on the target file which will fail if the target is /dev/tty.
(We'd already noted this in the context of the target being /dev/null.)
Even before that, it didn't work pleasantly, because libedit likes to
encode the command history file (to ensure successful reloading), which
renders it nigh unreadable, not to mention significantly different-looking
depending on exactly which libedit version you have. So let's forget using
write_history() for this purpose, and instead print the data ourselves,
using logic similar to that used to iterate over the history for newline
encoding/decoding purposes.
While we're at it, insert the ability to use the pager when \s is printing
to the terminal. This has been an acknowledged shortcoming of \s for many
years, so while you could argue it's not exactly a back-patchable bug fix
it still seems like a good improvement. Anyone who's seriously annoyed
at this can use "\s /dev/tty" or local equivalent to get the old behavior.
Experimentation with this showed that the history iteration logic was
actually rather broken when used with libedit. It turns out that with
libedit you have to use previous_history() not next_history() to advance
to more recent history entries. The easiest and most robust fix for this
seems to be to make a run-time test to verify which function to call.
We had not noticed this because libedit doesn't really need the newline
encoding logic: its own encoding ensures that command entries containing
newlines are reloaded correctly (unlike libreadline). So the effective
behavior with recent libedits was that only the oldest history entry got
newline-encoded or newline-decoded. However, because of yet other bugs in
history_set_pos(), some old versions of libedit allowed the existing loop
logic to reach entries besides the oldest, which means there may be libedit
~/.psql_history files out there containing encoded newlines in more than
just the oldest entry. To ensure we can reload such files, it seems
appropriate to back-patch this fix, even though that will result in some
incompatibility with older psql versions (ie, multiline history entries
written by a psql with this fix will look corrupted to a psql without it,
if its libedit is reasonably up to date).
Stepan Rutz and Tom Lane
Add asprintf(), pg_asprintf(), and psprintf() to simplify string
allocation and composition. Replacement implementations taken from
NetBSD.
Reviewed-by: Álvaro Herrera <alvherre@2ndquadrant.com>
Reviewed-by: Asif Naeem <anaeem.it@gmail.com>
All supported platforms support the C89 standard function atexit()
(SunOS 4 probably being the last one not to), and supporting both
makes the code clumsy.
This can change the meaning of queries, if the blank line happens to
occur in the middle of a quoted literal, as per complaint from Tomas Vondra.
Back-patch to all supported branches.
append_history(), if libreadline is new enough to have those functions
(they seem to be present at least since 4.2; but libedit may not have them).
This gives significantly saner behavior when two or more sessions overlap in
their use of the history file; although having two sessions exit at just the
same time is still perilous to your history. The behavior of \s remains
unchanged, ie, overwrite whatever was there.
Per bug #5052 from Marek Wójtowicz.
results (ie, an empty "broken" buffer) if memory overrun occurs anywhere
along the way to filling the buffer. The previous coding would just silently
discard portions of the intended buffer contents, as exhibited in trouble
report from Sam Mason. Also, tweak psql's main loop to correctly detect
and report such overruns. There's probably much more that should be done
in this line, but this is a start.
existing for backend GUC variables, and use this to eliminate repeated
fetching/parsing of psql variables in psql's inner loops. In a trivial
test with lots of 'select 1;' commands, psql's CPU time went down almost
10%, although of course the effect on total elapsed time was much less.
Per discussion about how to ensure the upcoming FETCH_COUNT patch doesn't
cost any performance when not being used.
places --- that risks corrupting data structures, losing sync with the
backend, etc. We now longjmp only from calls to readline, fgets, and
fread, which we assume are coded to protect themselves against interrupts
at undesirable times. This requires adding explicit tests for
cancel_pressed in long-running loops, but on the whole it's far cleaner.
Martijn van Oosterhout and Tom Lane.
> 1) Fix the problems with the \s command.
> When the saveHistory is executed by the \s command we must not do the
> conversion \n -> \x01 (per
> http://archives.postgresql.org/pgsql-hackers/2006-03/msg00317.php )
>
> 2) Fix the handling of Ctrl+C
>
> Now when you do
> wsdb=# select 'your long query here '
> wsdb-#
> and press afterwards the CtrlC the line "select 'your long query here
'"
> will be in the history
>
> (partly per
> http://archives.postgresql.org/pgsql-hackers/2006-03/msg00297.php )
>
> 3) Fix the handling of commands with not closed brackets, quotes,
double
> quotes. (now those commands are not splitted in parts...)
>
> 4) Fix the behaviour when SINGLELINE mode is used. (before it was
almost
> broken ;(
Sergey E. Koposov
Currently, while \e saves a single statement as one entry, interactive
statements are saved one line at a time. Ideally all statements
would be saved like \e does.
Sergey E. Koposov
history customizable through a variable named HISTFILE, analogous to
psql's already implemented HISTCONTROL and HISTSIZE variables, and
bash's HISTFILE-Variable.
The motivation was to be able to get psql to maintain separate
histories for separate databases. This is now easily achievable
through a line like the following in ~/.psqlrc:
\set HISTFILE ~/.psql_history-:DBNAME
Andreas Seltenreich
discussion on pgsql-hackers-win32 list. Documentation still needs to
be tweaked --- I'm not sure how to refer to the APPDATA folder in
user documentation.
