Tom Lane wrote:
> > but "one letter is enough" is not true since 9.3 that added
> > "latex-longtable" sharing the same start as "latex", and then
> > 9.5 added "asciidoc" with the same first letter as "aligned".
>
> Yeah, that text has clearly outstayed its welcome.
>
> > When a non-unique abbreviation is used, psql uses the first
> > match in an arbitrary order defined in do_pset() by
> > a cascade of pg_strncasecmp().
>
> Ugh. Should we not fix the code so that it complains if there's
> not a unique match? I would bet that the code was also written
> on the assumption that any abbrevation must be unique.
Here's a patch making "\pset format" reject ambiguous abbreviations.
Best regards,
--
Daniel Vérité
PostgreSQL-powered mailer: http://www.manitou-mail.org
Twitter: @DanielVerite
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index a1ca940..6e6d0f4 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -2589,8 +2589,7 @@ lo_import 152801
<literal>latex</literal> (uses <literal>tabular</literal>),
<literal>latex-longtable</literal>, <literal>troff-ms</literal>,
<literal>unaligned</literal>, or <literal>wrapped</literal>.
- Unique abbreviations are allowed. (That would mean one letter
- is enough.)
+ Unique abbreviations are allowed.
</para>
<para><literal>unaligned</literal> format writes all columns of a
row on one
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 0dea54d..1f23aaf 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -3637,28 +3637,52 @@ do_pset(const char *param, const char *value,
printQueryOpt *popt, bool quiet)
/* set format */
if (strcmp(param, "format") == 0)
{
+ static const struct fmt
+ {
+ const char *name;
+ enum printFormat number;
+ } formats[] =
+ {
+ {"aligned", PRINT_ALIGNED},
+ {"asciidoc", PRINT_ASCIIDOC},
+ {"html", PRINT_HTML},
+ {"latex", PRINT_LATEX},
+ {"latex-longtable", PRINT_LATEX_LONGTABLE},
+ {"troff-ms", PRINT_TROFF_MS},
+ {"unaligned", PRINT_UNALIGNED},
+ {"wrapped", PRINT_WRAPPED}
+ };
+
if (!value)
;
- else if (pg_strncasecmp("aligned", value, vallen) == 0)
- popt->topt.format = PRINT_ALIGNED;
- else if (pg_strncasecmp("asciidoc", value, vallen) == 0)
- popt->topt.format = PRINT_ASCIIDOC;
- else if (pg_strncasecmp("html", value, vallen) == 0)
- popt->topt.format = PRINT_HTML;
- else if (pg_strncasecmp("latex", value, vallen) == 0)
- popt->topt.format = PRINT_LATEX;
- else if (pg_strncasecmp("latex-longtable", value, vallen) == 0)
- popt->topt.format = PRINT_LATEX_LONGTABLE;
- else if (pg_strncasecmp("troff-ms", value, vallen) == 0)
- popt->topt.format = PRINT_TROFF_MS;
- else if (pg_strncasecmp("unaligned", value, vallen) == 0)
- popt->topt.format = PRINT_UNALIGNED;
- else if (pg_strncasecmp("wrapped", value, vallen) == 0)
- popt->topt.format = PRINT_WRAPPED;
else
{
- psql_error("\\pset: allowed formats are aligned,
asciidoc, html, latex, latex-longtable, troff-ms, unaligned, wrapped\n");
- return false;
+ int match_count = 0;
+ int first_match = 0;
+
+ /*
+ * Count the number of left-anchored matches. Exactly
one match
+ * must be found, otherwise error out.
+ */
+ for (int i = 0; i < lengthof(formats); i++)
+ {
+ if (pg_strncasecmp(formats[i].name, value,
vallen) == 0)
+ {
+ if (++match_count > 1)
+ {
+ psql_error("\\pset: ambiguous
abbreviation: \"%s\"\n", value);
+ return false;
+ }
+ first_match = i;
+ }
+ }
+ if (match_count == 0)
+ {
+ psql_error("\\pset: allowed formats are
aligned, asciidoc, html, latex, latex-longtable, troff-ms, unaligned,
wrapped\n");
+ return false;
+ }
+ else
+ popt->topt.format = formats[first_match].number;
}
}
