Thread: Tiny patch on print.c of psql

Hi all,

This is my 1st patch ever in C :-)... I was just borried by a bad psql
\H html output of an EXPLAIN

because it didnt respected spaces sent from backend like:

-> Sort
    -> Sort

I just remarked in this print.c the case of a white space wasnt handled
in the function escaping special caracters to HTML codes, so I added it
replacing a space by special html " " (& n b s p).

So we'll have now:

-> Sort
  -> Sort

... in the html generated

(see example at http://www.pack-solutions.net/~jpargudo/explain.html)

Then, every single space in the html source is replaced by this. The
source looks ugly, yes, I will look to *only replacing starting spaces*
of each row of the EXPLAIN, thats will be my 1st patch ever, version 2 :)

So I post this patch only FYI..  I had much fun playing with C a bit :-)
(yes, I dont code C, just a bit of Perl and Python).

Cheers! Thanks again for such a powerfull release.

--
Jean-Paul Argudo
www.PostgreSQLFr.org
--- postgresql-8.0.0/src/bin/psql/print.c    2005-01-01 06:43:08.000000000 +0100
+++ postgresql-8.0.0-patch/src/bin/psql/print.c    2005-01-20 21:54:56.000000000 +0100
@@ -617,6 +617,9 @@
             case '\'':
                 fputs("'", fout);
                 break;
+            case ' ':
+                fputs(" ", fout);
+                break;
             default:
                 fputc(*p, fout);
         }

This has been saved for the 8.1 release:

    http://momjian.postgresql.org/cgi-bin/pgpatches2

---------------------------------------------------------------------------

Jean-Paul Argudo wrote:
> Hi all,
>
> This is my 1st patch ever in C :-)... I was just borried by a bad psql
> \H html output of an EXPLAIN
>
> because it didnt respected spaces sent from backend like:
>
> -> Sort
>     -> Sort
>
> I just remarked in this print.c the case of a white space wasnt handled
> in the function escaping special caracters to HTML codes, so I added it
> replacing a space by special html " " (& n b s p).
>
> So we'll have now:
>
> -> Sort
>   -> Sort
>
> ... in the html generated
>
> (see example at http://www.pack-solutions.net/~jpargudo/explain.html)
>
> Then, every single space in the html source is replaced by this. The
> source looks ugly, yes, I will look to *only replacing starting spaces*
> of each row of the EXPLAIN, thats will be my 1st patch ever, version 2 :)
>
> So I post this patch only FYI..  I had much fun playing with C a bit :-)
> (yes, I dont code C, just a bit of Perl and Python).
>
> Cheers! Thanks again for such a powerfull release.
>
> --
> Jean-Paul Argudo
> www.PostgreSQLFr.org


>
> ---------------------------(end of broadcast)---------------------------
> TIP 9: the planner will ignore your desire to choose an index scan if your
>       joining column's datatypes do not match

--
  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

I have applied your patch, and added the optimization that only leading
spaces are converted to ' ', as you suggested.

---------------------------------------------------------------------------

Jean-Paul Argudo wrote:
> Hi all,
>
> This is my 1st patch ever in C :-)... I was just borried by a bad psql
> \H html output of an EXPLAIN
>
> because it didnt respected spaces sent from backend like:
>
> -> Sort
>     -> Sort
>
> I just remarked in this print.c the case of a white space wasnt handled
> in the function escaping special caracters to HTML codes, so I added it
> replacing a space by special html " " (& n b s p).
>
> So we'll have now:
>
> -> Sort
>   -> Sort
>
> ... in the html generated
>
> (see example at http://www.pack-solutions.net/~jpargudo/explain.html)
>
> Then, every single space in the html source is replaced by this. The
> source looks ugly, yes, I will look to *only replacing starting spaces*
> of each row of the EXPLAIN, thats will be my 1st patch ever, version 2 :)
>
> So I post this patch only FYI..  I had much fun playing with C a bit :-)
> (yes, I dont code C, just a bit of Perl and Python).
>
> Cheers! Thanks again for such a powerfull release.
>
> --
> Jean-Paul Argudo
> www.PostgreSQLFr.org


>
> ---------------------------(end of broadcast)---------------------------
> TIP 9: the planner will ignore your desire to choose an index scan if your
>       joining column's datatypes do not match

--
  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: src/bin/psql/print.c
===================================================================
RCS file: /cvsroot/pgsql/src/bin/psql/print.c,v
retrieving revision 1.59
diff -c -c -r1.59 print.c
*** src/bin/psql/print.c    14 Jun 2005 02:57:41 -0000    1.59
--- src/bin/psql/print.c    14 Jun 2005 22:14:20 -0000
***************
*** 595,602 ****
  html_escaped_print(const char *in, FILE *fout)
  {
      const char *p;
!
      for (p = in; *p; p++)
          switch (*p)
          {
              case '&':
--- 595,604 ----
  html_escaped_print(const char *in, FILE *fout)
  {
      const char *p;
!     bool    leading_space = true;
!
      for (p = in; *p; p++)
+     {
          switch (*p)
          {
              case '&':
***************
*** 617,625 ****
--- 619,637 ----
              case '\'':
                  fputs("'", fout);
                  break;
+             case ' ':
+                 /* protect leading space, for EXPLAIN output */
+                 if (leading_space)
+                     fputs(" ", fout);
+                 else
+                     fputs(" ", fout);
+                 break;
              default:
                  fputc(*p, fout);
          }
+         if (*p != ' ')
+             leading_space = false;
+     }
  }