I have applied a modified version of your patch. I moved the prompt
'text' field as optional before name, and removed the default prompt
string, which seemed un-Unix-like.
I also simplified when stdin/stdout is used. If stdin is the terminal,
it seems it makes no difference if we use the terminal or stdin. Now,
prompt uses the terminal unless -f is used. I think this simplifies its
behavior. I realize cases where stdin is the terminal and stdout is not
behave differently in the new patch (prompt goes to the terminal and not
to stdout), but I think the previous behavior was too confusing to be
useful. I can adjust this if people want different behavior.
Update version attached.
---------------------------------------------------------------------------
Chad Wagner wrote:
> On 2/17/07, Tom Lane <[EMAIL PROTECTED]> wrote:
> >
> > "Chad Wagner" <[EMAIL PROTECTED]> writes:
> > > Would it make sense to say:
> > > 1. if pset.notty is set and '-f' switch is not set then use
> > simple_prompt
> > > 2. else then use gets_fromFile(stdin) <or some other alternative?>
> >
> > Actually, there's another issue, which is where to send the prompt.
> > If we're using /dev/tty the answer is clear, but if we're proposing to
> > read from stdin then it's not necessarily the case that stdout (or even
> > stderr) is appropriate.
> >
> > Arguably a prompt is useless except to a human user, so maybe the rule
> > is "if stdin is a tty according to pset.notty, then prompt to /dev/tty;
> > otherwise suppress the prompt altogether". Or we could prompt to stderr
> > instead of /dev/tty in this case. I'm not sure if there are plausible
> > use-cases where stdin leads to the terminal and stderr doesn't.
> >
>
> pset.notty will be set to 1 if either stdin or stdout is not a tty. So in
> the case where they are redirecting both input and output then it will
> prompt on /dev/tty, otherwise the prompt would go out on stdout.
>
> I was thinking perhaps it should look at the '-q' quiet switch for
> determining whether to display prompt at all. So perhaps with a '-q' switch
> instead of dumping the prompt to stdout it should always be sent to
> /dev/tty. Also, I think in general most users of this feature that would be
> "scripting" output (via expect or similar) would probably just use the '-v'
> switches.
>
> BTW, attached is the latest version of this patch that includes the code
> (and updates to the psql-ref.sgml) I talked about earlier. Not sure if
> gets_fromFile is favored, or perhaps the creation of a psql_prompt_var
> routine that takes into account some of what simple_prompt is doing but
> considering the logic we are discussing.
[ Attachment, skipping... ]
>
> ---------------------------(end of broadcast)---------------------------
> TIP 9: In versions below 8.0, the planner will ignore your desire to
> choose an index scan if your joining column's datatypes do not
> match
--
Bruce Momjian <[EMAIL PROTECTED]> http://momjian.us
EnterpriseDB http://www.enterprisedb.com
+ If your life is a hard drive, Christ can be your backup. +
Index: doc/src/sgml/ref/psql-ref.sgml
===================================================================
RCS file: /cvsroot/pgsql/doc/src/sgml/ref/psql-ref.sgml,v
retrieving revision 1.186
diff -c -c -r1.186 psql-ref.sgml
*** doc/src/sgml/ref/psql-ref.sgml 21 Feb 2007 23:22:42 -0000 1.186
--- doc/src/sgml/ref/psql-ref.sgml 23 Feb 2007 18:14:04 -0000
***************
*** 1430,1435 ****
--- 1430,1453 ----
</varlistentry>
<varlistentry>
+ <term><literal>\prompt [ <replaceable class="parameter">text</replaceable> ] <replaceable class="parameter">name</replaceable></literal></term>
+ <listitem>
+ <para>
+ Prompts the user to set variable <replaceable
+ class="parameter">name</>. An optional prompt, <replaceable
+ class="parameter">text</>, can be specified. (For multi-word
+ prompts, use single-quotes.)
+ </para>
+
+ <para>
+ By default, <literal>\prompt</> uses the terminal for input and
+ output. However, if the <option>-f</> command line switch is
+ used, <literal>\prompt</> uses standard input and standard output.
+ </para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
<term><literal>\pset <replaceable class="parameter">parameter</replaceable> [ <replaceable class="parameter">value</replaceable> ]</literal></term>
<listitem>
Index: src/bin/psql/command.c
===================================================================
RCS file: /cvsroot/pgsql/src/bin/psql/command.c,v
retrieving revision 1.177
diff -c -c -r1.177 command.c
*** src/bin/psql/command.c 5 Jan 2007 22:19:49 -0000 1.177
--- src/bin/psql/command.c 23 Feb 2007 18:14:06 -0000
***************
*** 712,717 ****
--- 712,768 ----
free(pw2);
}
+ /* \prompt -- prompt and set variable */
+ else if (strcmp(cmd, "prompt") == 0)
+ {
+ char *opt, *prompt_text = NULL;
+ char *arg1, *arg2;
+
+ arg1 = psql_scan_slash_option(scan_state, OT_NORMAL, NULL, false);
+ arg2 = psql_scan_slash_option(scan_state, OT_NORMAL, NULL, false);
+
+ if (!arg1)
+ {
+ psql_error("\\%s: missing required argument\n", cmd);
+ success = false;
+ }
+ else
+ {
+ char *result;
+
+ if (arg2)
+ {
+ prompt_text = arg1;
+ opt = arg2;
+ }
+ else
+ opt = arg1;
+
+ if (!pset.inputfile)
+ result = simple_prompt(prompt_text, 4096, true);
+ else
+ {
+ if (prompt_text)
+ {
+ fputs(prompt_text, stdout);
+ fflush(stdout);
+ }
+ result = gets_fromFile(stdin);
+ }
+
+ if (!SetVariable(pset.vars, opt, result))
+ {
+ psql_error("\\%s: error\n", cmd);
+ success = false;
+ }
+
+ free(result);
+ if (prompt_text)
+ free(prompt_text);
+ free(opt);
+ }
+ }
+
/* \pset -- set printing parameters */
else if (strcmp(cmd, "pset") == 0)
{
Index: src/bin/psql/help.c
===================================================================
RCS file: /cvsroot/pgsql/src/bin/psql/help.c,v
retrieving revision 1.116
diff -c -c -r1.116 help.c
*** src/bin/psql/help.c 5 Jan 2007 22:19:49 -0000 1.116
--- src/bin/psql/help.c 23 Feb 2007 18:14:06 -0000
***************
*** 161,167 ****
{
FILE *output;
! output = PageOutput(67, pager);
/* if you add/remove a line here, change the row count above */
--- 161,167 ----
{
FILE *output;
! output = PageOutput(69, pager);
/* if you add/remove a line here, change the row count above */
***************
*** 184,189 ****
--- 184,191 ----
fprintf(output, _(" \\timing toggle timing of commands (currently %s)\n"),
ON(pset.timing));
fprintf(output, _(" \\unset NAME unset (delete) internal variable\n"));
+ fprintf(output, _(" \\prompt [TEXT] NAME\n"
+ " prompt user to set internal variable\n"));
fprintf(output, _(" \\! [COMMAND] execute command in shell or start interactive shell\n"));
fprintf(output, "\n");
Index: src/bin/psql/tab-complete.c
===================================================================
RCS file: /cvsroot/pgsql/src/bin/psql/tab-complete.c,v
retrieving revision 1.158
diff -c -c -r1.158 tab-complete.c
*** src/bin/psql/tab-complete.c 7 Feb 2007 00:52:35 -0000 1.158
--- src/bin/psql/tab-complete.c 23 Feb 2007 18:14:07 -0000
***************
*** 542,548 ****
"\\e", "\\echo", "\\encoding",
"\\f", "\\g", "\\h", "\\help", "\\H", "\\i", "\\l",
"\\lo_import", "\\lo_export", "\\lo_list", "\\lo_unlink",
! "\\o", "\\p", "\\password", "\\pset", "\\q", "\\qecho", "\\r",
"\\set", "\\t", "\\T",
"\\timing", "\\unset", "\\x", "\\w", "\\z", "\\!", NULL
};
--- 542,548 ----
"\\e", "\\echo", "\\encoding",
"\\f", "\\g", "\\h", "\\help", "\\H", "\\i", "\\l",
"\\lo_import", "\\lo_export", "\\lo_list", "\\lo_unlink",
! "\\o", "\\p", "\\password", "\\prompt", "\\pset", "\\q", "\\qecho", "\\r",
"\\set", "\\t", "\\T",
"\\timing", "\\unset", "\\x", "\\w", "\\z", "\\!", NULL
};
---------------------------(end of broadcast)---------------------------
TIP 6: explain analyze is your friend
