Re: psql: customizable readline history filename - Mailing list pgsql-patches

Andreas Seltenreich wrote:
> Hi,
>
> the following patch makes the filename used to store the readline
> 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

I have applied your patch with slight modifications; new version
attached.

Win32 doesn't have tilde expansion, so your idea of using
"~/.psql_history" as a default would not work --- I had to keep the
get_home_path() code in there.

I decided to make psql_history a file static variable, so we would not
have to recompute its value when writing the history file.

I noticed your documentation example had a space before :DBNAME --- I
removed the space.

You had the idea of not saving the history on exit if HISTFILE is not
set.  I don't think we have community agreement on that change, and I
bet we wouldn't get it.  (I have removed your documentation mention of
this.)  I think setting HISTSIZE to zero has that effect already if
people want it.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073
Index: doc/src/sgml/ref/psql-ref.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/ref/psql-ref.sgml,v
retrieving revision 1.139
diff -c -c -r1.139 psql-ref.sgml
*** doc/src/sgml/ref/psql-ref.sgml    9 Jun 2005 15:27:26 -0000    1.139
--- doc/src/sgml/ref/psql-ref.sgml    10 Jun 2005 15:33:22 -0000
***************
*** 1988,1993 ****
--- 1988,2015 ----
        </varlistentry>

        <varlistentry>
+         <term><varname>HISTFILE</varname></term>
+         <listitem>
+         <para>
+         This variable contains the filename used to save the history.
+         Its default value is <filename>~/.psql_history</filename>.
+         For example, use:
+ <programlisting>
+ \set HISTFILE ~/.psql_history-:DBNAME
+ </programlisting>
+         in your <filename>~/.psqlrc</filename> will get psql to
+         maintain a separate history for each database.
+         </para>
+         <note>
+         <para>
+         This feature was shamelessly plagiarized from
+         <application>Bash</application>.
+         </para>
+         </note>
+         </listitem>
+       </varlistentry>
+
+       <varlistentry>
          <term><varname>HISTSIZE</varname></term>
          <listitem>
          <para>
Index: src/bin/psql/input.c
===================================================================
RCS file: /cvsroot/pgsql/src/bin/psql/input.c,v
retrieving revision 1.43
diff -c -c -r1.43 input.c
*** src/bin/psql/input.c    6 Jan 2005 18:29:09 -0000    1.43
--- src/bin/psql/input.c    10 Jun 2005 15:33:23 -0000
***************
*** 24,29 ****
--- 24,31 ----
  #ifdef USE_READLINE
  static bool useReadline;
  static bool useHistory;
+ char  *psql_history;
+

  enum histcontrol
  {
***************
*** 177,192 ****
          if (GetVariable(pset.vars, "HISTSIZE") == NULL)
              SetVariable(pset.vars, "HISTSIZE", "500");
          using_history();
!         if (get_home_path(home))
          {
!             char       *psql_history;

!             psql_history = pg_malloc(strlen(home) + 1 +
!                                      strlen(PSQLHISTORY) + 1);
!             sprintf(psql_history, "%s/%s", home, PSQLHISTORY);
              read_history(psql_history);
-             free(psql_history);
-         }
      }
  #endif

--- 179,202 ----
          if (GetVariable(pset.vars, "HISTSIZE") == NULL)
              SetVariable(pset.vars, "HISTSIZE", "500");
          using_history();
!
!         if (GetVariable(pset.vars, "HISTFILE") == NULL)
!         {
!             if (get_home_path(home))
!             {
!                 psql_history = pg_malloc(strlen(home) + 1 +
!                                          strlen(PSQLHISTORY) + 1);
!                 snprintf(psql_history, MAXPGPATH, "%s/%s", home, PSQLHISTORY);
!             }
!         }
!         else
          {
!             psql_history = pg_strdup(GetVariable(pset.vars, "HISTFILE"));
!             expand_tilde(&psql_history);
!         }

!         if (psql_history)
              read_history(psql_history);
      }
  #endif

***************
*** 227,251 ****
  #endif
  {
  #ifdef USE_READLINE
!     if (useHistory)
      {
!         char        home[MAXPGPATH];

!         if (get_home_path(home))
!         {
!             char       *psql_history;
!             int            hist_size;
!
!             hist_size = GetVariableNum(pset.vars, "HISTSIZE", -1, -1, true);
!             if (hist_size >= 0)
!                 stifle_history(hist_size);
!
!             psql_history = pg_malloc(strlen(home) + 1 +
!                                      strlen(PSQLHISTORY) + 1);
!             sprintf(psql_history, "%s/%s", home, PSQLHISTORY);
!             write_history(psql_history);
!             free(psql_history);
!         }
      }
  #endif
  }
--- 237,253 ----
  #endif
  {
  #ifdef USE_READLINE
!     if (useHistory && psql_history)
      {
!         int            hist_size;

!         hist_size = GetVariableNum(pset.vars, "HISTSIZE", -1, -1, true);
!         if (hist_size >= 0)
!             stifle_history(hist_size);
!
!         saveHistory(psql_history);
!         free(psql_history);
!         psql_history = NULL;
      }
  #endif
  }