From 511ae628f31b4e791cd5c7836e46cb84dcf145fd Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Mon, 30 Jan 2017 16:37:15 -0500
Subject: [PATCH] Make psql reject attempts to set special variables to invalid
values.
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Previously, if the user set a special variable such as ECHO to an
unrecognized value, psql would bleat but store the new value anyway, and
then fall back to a default setting for the behavior controlled by the
variable. This was agreed to be a not particularly good idea. With
this patch, invalid values result in an error message and no change in
state.
(But this applies only to variables that affect psql's behavior; purely
informational variables such as ENCODING can still be set to random
values.)
To do this, modify the API for psql's assign-hook functions so that they
can return an OK/not OK result, and give them the responsibility for
printing error messages when they reject a value. Adjust the APIs for
ParseVariableBool and ParseVariableNum to support the new behavior
conveniently.
In passing, document the variable VERSION, which had somehow escaped that.
And improve the quite-inadequate commenting in psql/variables.c.
Daniel Vérité, reviewed by Rahila Syed, some further tweaking by me
Discussion: https://postgr.es/m/7356e741-fa59-4146-a8eb-cf95fd6b21fb@mm
---
doc/src/sgml/ref/psql-ref.sgml | 33 +++--
src/bin/psql/command.c | 82 ++++++-----
src/bin/psql/common.c | 1 -
src/bin/psql/input.c | 2 +-
src/bin/psql/mainloop.c | 2 +-
src/bin/psql/startup.c | 121 ++++++++-------
src/bin/psql/variables.c | 228 +++++++++++++++++++++--------
src/bin/psql/variables.h | 50 +++++--
src/test/regress/expected/psql.out | 11 +-
src/test/regress/sql/psql.sql | 8 +
10 files changed, 356 insertions(+), 182 deletions(-)
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 640fe12bbf6..4e51e90906c 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -3078,10 +3078,8 @@ bar
by <application>psql</application>. They represent certain option
settings that can be changed at run time by altering the value of
the variable, or in some cases represent changeable state of
- <application>psql</application>. Although
- you can use these variables for other purposes, this is not
- recommended, as the program behavior might grow really strange
- really quickly. By convention, all specially treated variables' names
+ <application>psql</application>.
+ By convention, all specially treated variables' names
consist of all upper-case ASCII letters (and possibly digits and
underscores). To ensure maximum compatibility in the future, avoid
using such variable names for your own purposes. A list of all specially
@@ -3170,12 +3168,11 @@ bar
start-up, use the switch <option>-a</option>. If set to
<literal>queries</literal>,
<application>psql</application> prints each query to standard output
- as it is sent to the server. The switch for this is
+ as it is sent to the server. The switch to select this behavior is
<option>-e</option>. If set to <literal>errors</literal>, then only
failed queries are displayed on standard error output. The switch
- for this is <option>-b</option>. If unset, or if set to
- <literal>none</literal> (or any other value than those above) then
- no queries are displayed.
+ for this behavior is <option>-b</option>. If unset, or if set to
+ <literal>none</literal>, then no queries are displayed.
</para>
</listitem>
</varlistentry>
@@ -3201,6 +3198,9 @@ bar
<listitem>
<para>
The current client character set encoding.
+ This is set every time you connect to a database (including
+ program start-up), and when you change the encoding
+ with <literal>\encoding</>, but it can be unset.
</para>
</listitem>
</varlistentry>
@@ -3241,9 +3241,8 @@ bar
list. If set to a value of <literal>ignoredups</literal>, lines
matching the previous history line are not entered. A value of
<literal>ignoreboth</literal> combines the two options. If
- unset, or if set to <literal>none</literal> (or any other value
- than those above), all lines read in interactive mode are
- saved on the history list.
+ unset, or if set to <literal>none</literal> (the default), all lines
+ read in interactive mode are saved on the history list.
</para>
<note>
<para>
@@ -3312,7 +3311,7 @@ bar
to an interactive session of <application>psql</application>
will terminate the application. If set to a numeric value,
that many <acronym>EOF</> characters are ignored before the
- application terminates. If the variable is set but has no
+ application terminates. If the variable is set but not to a
numeric value, the default is 10.
</para>
<note>
@@ -3477,6 +3476,16 @@ bar
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><varname>VERSION</varname></term>
+ <listitem>
+ <para>
+ This variable is set at program start-up to
+ reflect <application>psql</>'s version. It can be unset or changed.
+ </para>
+ </listitem>
+ </varlistentry>
+
</variablelist>
</refsect3>
diff --git a/src/bin/psql/command.c b/src/bin/psql/command.c
index 0c164a339c1..f17f6107175 100644
--- a/src/bin/psql/command.c
+++ b/src/bin/psql/command.c
@@ -248,31 +248,37 @@ exec_command(const char *cmd,
*opt2,
*opt3,
*opt4;
- enum trivalue reuse_previous;
+ enum trivalue reuse_previous = TRI_DEFAULT;
opt1 = read_connect_arg(scan_state);
if (opt1 != NULL && strncmp(opt1, prefix, sizeof(prefix) - 1) == 0)
{
- reuse_previous =
- ParseVariableBool(opt1 + sizeof(prefix) - 1, prefix) ?
- TRI_YES : TRI_NO;
+ bool on_off;
- free(opt1);
- opt1 = read_connect_arg(scan_state);
+ success = ParseVariableBool(opt1 + sizeof(prefix) - 1,
+ "-reuse-previous",
+ &on_off);
+ if (success)
+ {
+ reuse_previous = on_off ? TRI_YES : TRI_NO;
+ free(opt1);
+ opt1 = read_connect_arg(scan_state);
+ }
}
- else
- reuse_previous = TRI_DEFAULT;
- opt2 = read_connect_arg(scan_state);
- opt3 = read_connect_arg(scan_state);
- opt4 = read_connect_arg(scan_state);
+ if (success) /* give up if reuse_previous was invalid */
+ {
+ opt2 = read_connect_arg(scan_state);
+ opt3 = read_connect_arg(scan_state);
+ opt4 = read_connect_arg(scan_state);
- success = do_connect(reuse_previous, opt1, opt2, opt3, opt4);
+ success = do_connect(reuse_previous, opt1, opt2, opt3, opt4);
+ free(opt2);
+ free(opt3);
+ free(opt4);
+ }
free(opt1);
- free(opt2);
- free(opt3);
- free(opt4);
}
/* \cd */
@@ -1208,10 +1214,7 @@ exec_command(const char *cmd,
if (result &&
!SetVariable(pset.vars, opt, result))
- {
- psql_error("\\%s: error while setting variable\n", cmd);
success = false;
- }
if (result)
free(result);
@@ -1325,10 +1328,8 @@ exec_command(const char *cmd,
}
if (!SetVariable(pset.vars, opt0, newval))
- {
- psql_error("\\%s: error while setting variable\n", cmd);
success = false;
- }
+
free(newval);
}
free(opt0);
@@ -1564,7 +1565,7 @@ exec_command(const char *cmd,
OT_NORMAL, NULL, false);
if (opt)
- pset.timing = ParseVariableBool(opt, "\\timing");
+ success = ParseVariableBool(opt, "\\timing", &pset.timing);
else
pset.timing = !pset.timing;
if (!pset.quiet)
@@ -1589,10 +1590,8 @@ exec_command(const char *cmd,
success = false;
}
else if (!SetVariable(pset.vars, opt, NULL))
- {
- psql_error("\\%s: error while setting variable\n", cmd);
success = false;
- }
+
free(opt);
}
@@ -2593,7 +2592,6 @@ do_pset(const char *param, const char *value, printQueryOpt *popt, bool quiet)
psql_error("\\pset: allowed formats are unaligned, aligned, wrapped, html, asciidoc, latex, latex-longtable, troff-ms\n");
return false;
}
-
}
/* set table line style */
@@ -2612,7 +2610,6 @@ do_pset(const char *param, const char *value, printQueryOpt *popt, bool quiet)
psql_error("\\pset: allowed line styles are ascii, old-ascii, unicode\n");
return false;
}
-
}
/* set unicode border line style */
@@ -2665,7 +2662,6 @@ do_pset(const char *param, const char *value, printQueryOpt *popt, bool quiet)
{
if (value)
popt->topt.border = atoi(value);
-
}
/* set expanded/vertical mode */
@@ -2676,7 +2672,17 @@ do_pset(const char *param, const char *value, printQueryOpt *popt, bool quiet)
if (value && pg_strcasecmp(value, "auto") == 0)
popt->topt.expanded = 2;
else if (value)
- popt->topt.expanded = ParseVariableBool(value, param);
+ {
+ bool on_off;
+
+ if (ParseVariableBool(value, NULL, &on_off))
+ popt->topt.expanded = on_off ? 1 : 0;
+ else
+ {
+ PsqlVarEnumError(param, value, "on, off, auto");
+ return false;
+ }
+ }
else
popt->topt.expanded = !popt->topt.expanded;
}
@@ -2685,7 +2691,7 @@ do_pset(const char *param, const char *value, printQueryOpt *popt, bool quiet)
else if (strcmp(param, "numericlocale") == 0)
{
if (value)
- popt->topt.numericLocale = ParseVariableBool(value, param);
+ return ParseVariableBool(value, param, &popt->topt.numericLocale);
else
popt->topt.numericLocale = !popt->topt.numericLocale;
}
@@ -2740,7 +2746,7 @@ do_pset(const char *param, const char *value, printQueryOpt *popt, bool quiet)
else if (strcmp(param, "t") == 0 || strcmp(param, "tuples_only") == 0)
{
if (value)
- popt->topt.tuples_only = ParseVariableBool(value, param);
+ return ParseVariableBool(value, param, &popt->topt.tuples_only);
else
popt->topt.tuples_only = !popt->topt.tuples_only;
}
@@ -2772,10 +2778,14 @@ do_pset(const char *param, const char *value, printQueryOpt *popt, bool quiet)
popt->topt.pager = 2;
else if (value)
{
- if (ParseVariableBool(value, param))
- popt->topt.pager = 1;
- else
- popt->topt.pager = 0;
+ bool on_off;
+
+ if (!ParseVariableBool(value, NULL, &on_off))
+ {
+ PsqlVarEnumError(param, value, "on, off, always");
+ return false;
+ }
+ popt->topt.pager = on_off ? 1 : 0;
}
else if (popt->topt.pager == 1)
popt->topt.pager = 0;
@@ -2794,7 +2804,7 @@ do_pset(const char *param, const char *value, printQueryOpt *popt, bool quiet)
else if (strcmp(param, "footer") == 0)
{
if (value)
- popt->topt.default_footer = ParseVariableBool(value, param);
+ return ParseVariableBool(value, param, &popt->topt.default_footer);
else
popt->topt.default_footer = !popt->topt.default_footer;
}
diff --git a/src/bin/psql/common.c b/src/bin/psql/common.c
index e1b04de0132..6e3acdc416e 100644
--- a/src/bin/psql/common.c
+++ b/src/bin/psql/common.c
@@ -841,7 +841,6 @@ StoreQueryTuple(const PGresult *result)
if (!SetVariable(pset.vars, varname, value))
{
- psql_error("could not set variable \"%s\"\n", varname);
free(varname);
success = false;
break;
diff --git a/src/bin/psql/input.c b/src/bin/psql/input.c
index 972bea4cbf8..3e3e97ad0d2 100644
--- a/src/bin/psql/input.c
+++ b/src/bin/psql/input.c
@@ -541,7 +541,7 @@ finishInput(void)
{
int hist_size;
- hist_size = GetVariableNum(pset.vars, "HISTSIZE", 500, -1, true);
+ hist_size = GetVariableNum(pset.vars, "HISTSIZE", 500, -1);
(void) saveHistory(psql_history, hist_size);
free(psql_history);
psql_history = NULL;
diff --git a/src/bin/psql/mainloop.c b/src/bin/psql/mainloop.c
index bb306a43271..dc25b4babc5 100644
--- a/src/bin/psql/mainloop.c
+++ b/src/bin/psql/mainloop.c
@@ -162,7 +162,7 @@ MainLoop(FILE *source)
/* This tries to mimic bash's IGNOREEOF feature. */
count_eof++;
- if (count_eof < GetVariableNum(pset.vars, "IGNOREEOF", 0, 10, false))
+ if (count_eof < GetVariableNum(pset.vars, "IGNOREEOF", 0, 10))
{
if (!pset.quiet)
printf(_("Use \"\\q\" to leave %s.\n"), pset.progname);
diff --git a/src/bin/psql/startup.c b/src/bin/psql/startup.c
index 85aac4a1659..0574b5bdfb1 100644
--- a/src/bin/psql/startup.c
+++ b/src/bin/psql/startup.c
@@ -588,11 +588,7 @@ parse_psql_options(int argc, char *argv[], struct adhoc_opts * options)
{
*equal_loc = '\0';
if (!SetVariable(pset.vars, value, equal_loc + 1))
- {
- fprintf(stderr, _("%s: could not set variable \"%s\"\n"),
- pset.progname, value);
exit(EXIT_FAILURE);
- }
}
free(value);
@@ -786,43 +782,47 @@ showVersion(void)
* This isn't an amazingly good place for them, but neither is anywhere else.
*/
-static void
+static bool
autocommit_hook(const char *newval)
{
- pset.autocommit = ParseVariableBool(newval, "AUTOCOMMIT");
+ return ParseVariableBool(newval, "AUTOCOMMIT", &pset.autocommit);
}
-static void
+static bool
on_error_stop_hook(const char *newval)
{
- pset.on_error_stop = ParseVariableBool(newval, "ON_ERROR_STOP");
+ return ParseVariableBool(newval, "ON_ERROR_STOP", &pset.on_error_stop);
}
-static void
+static bool
quiet_hook(const char *newval)
{
- pset.quiet = ParseVariableBool(newval, "QUIET");
+ return ParseVariableBool(newval, "QUIET", &pset.quiet);
}
-static void
+static bool
singleline_hook(const char *newval)
{
- pset.singleline = ParseVariableBool(newval, "SINGLELINE");
+ return ParseVariableBool(newval, "SINGLELINE", &pset.singleline);
}
-static void
+static bool
singlestep_hook(const char *newval)
{
- pset.singlestep = ParseVariableBool(newval, "SINGLESTEP");
+ return ParseVariableBool(newval, "SINGLESTEP", &pset.singlestep);
}
-static void
+static bool
fetch_count_hook(const char *newval)
{
- pset.fetch_count = ParseVariableNum(newval, -1, -1, false);
+ if (newval == NULL)
+ pset.fetch_count = -1; /* default value */
+ else if (!ParseVariableNum(newval, "FETCH_COUNT", &pset.fetch_count))
+ return false;
+ return true;
}
-static void
+static bool
echo_hook(const char *newval)
{
if (newval == NULL)
@@ -837,39 +837,57 @@ echo_hook(const char *newval)
pset.echo = PSQL_ECHO_NONE;
else
{
- psql_error("unrecognized value \"%s\" for \"%s\"; assuming \"%s\"\n",
- newval, "ECHO", "none");
- pset.echo = PSQL_ECHO_NONE;
+ PsqlVarEnumError("ECHO", newval, "none, errors, queries, all");
+ return false;
}
+ return true;
}
-static void
+static bool
echo_hidden_hook(const char *newval)
{
if (newval == NULL)
pset.echo_hidden = PSQL_ECHO_HIDDEN_OFF;
else if (pg_strcasecmp(newval, "noexec") == 0)
pset.echo_hidden = PSQL_ECHO_HIDDEN_NOEXEC;
- else if (ParseVariableBool(newval, "ECHO_HIDDEN"))
- pset.echo_hidden = PSQL_ECHO_HIDDEN_ON;
- else /* ParseVariableBool printed msg if needed */
- pset.echo_hidden = PSQL_ECHO_HIDDEN_OFF;
+ else
+ {
+ bool on_off;
+
+ if (ParseVariableBool(newval, NULL, &on_off))
+ pset.echo_hidden = on_off ? PSQL_ECHO_HIDDEN_ON : PSQL_ECHO_HIDDEN_OFF;
+ else
+ {
+ PsqlVarEnumError("ECHO_HIDDEN", newval, "on, off, noexec");
+ return false;
+ }
+ }
+ return true;
}
-static void
+static bool
on_error_rollback_hook(const char *newval)
{
if (newval == NULL)
pset.on_error_rollback = PSQL_ERROR_ROLLBACK_OFF;
else if (pg_strcasecmp(newval, "interactive") == 0)
pset.on_error_rollback = PSQL_ERROR_ROLLBACK_INTERACTIVE;
- else if (ParseVariableBool(newval, "ON_ERROR_ROLLBACK"))
- pset.on_error_rollback = PSQL_ERROR_ROLLBACK_ON;
- else /* ParseVariableBool printed msg if needed */
- pset.on_error_rollback = PSQL_ERROR_ROLLBACK_OFF;
+ else
+ {
+ bool on_off;
+
+ if (ParseVariableBool(newval, NULL, &on_off))
+ pset.on_error_rollback = on_off ? PSQL_ERROR_ROLLBACK_ON : PSQL_ERROR_ROLLBACK_OFF;
+ else
+ {
+ PsqlVarEnumError("ON_ERROR_ROLLBACK", newval, "on, off, interactive");
+ return false;
+ }
+ }
+ return true;
}
-static void
+static bool
comp_keyword_case_hook(const char *newval)
{
if (newval == NULL)
@@ -884,13 +902,14 @@ comp_keyword_case_hook(const char *newval)
pset.comp_case = PSQL_COMP_CASE_LOWER;
else
{
- psql_error("unrecognized value \"%s\" for \"%s\"; assuming \"%s\"\n",
- newval, "COMP_KEYWORD_CASE", "preserve-upper");
- pset.comp_case = PSQL_COMP_CASE_PRESERVE_UPPER;
+ PsqlVarEnumError("COMP_KEYWORD_CASE", newval,
+ "lower, upper, preserve-lower, preserve-upper");
+ return false;
}
+ return true;
}
-static void
+static bool
histcontrol_hook(const char *newval)
{
if (newval == NULL)
@@ -905,31 +924,35 @@ histcontrol_hook(const char *newval)
pset.histcontrol = hctl_none;
else
{
- psql_error("unrecognized value \"%s\" for \"%s\"; assuming \"%s\"\n",
- newval, "HISTCONTROL", "none");
- pset.histcontrol = hctl_none;
+ PsqlVarEnumError("HISTCONTROL", newval,
+ "none, ignorespace, ignoredups, ignoreboth");
+ return false;
}
+ return true;
}
-static void
+static bool
prompt1_hook(const char *newval)
{
pset.prompt1 = newval ? newval : "";
+ return true;
}
-static void
+static bool
prompt2_hook(const char *newval)
{
pset.prompt2 = newval ? newval : "";
+ return true;
}
-static void
+static bool
prompt3_hook(const char *newval)
{
pset.prompt3 = newval ? newval : "";
+ return true;
}
-static void
+static bool
verbosity_hook(const char *newval)
{
if (newval == NULL)
@@ -942,16 +965,16 @@ verbosity_hook(const char *newval)
pset.verbosity = PQERRORS_VERBOSE;
else
{
- psql_error("unrecognized value \"%s\" for \"%s\"; assuming \"%s\"\n",
- newval, "VERBOSITY", "default");
- pset.verbosity = PQERRORS_DEFAULT;
+ PsqlVarEnumError("VERBOSITY", newval, "default, terse, verbose");
+ return false;
}
if (pset.db)
PQsetErrorVerbosity(pset.db, pset.verbosity);
+ return true;
}
-static void
+static bool
show_context_hook(const char *newval)
{
if (newval == NULL)
@@ -964,13 +987,13 @@ show_context_hook(const char *newval)
pset.show_context = PQSHOW_CONTEXT_ALWAYS;
else
{
- psql_error("unrecognized value \"%s\" for \"%s\"; assuming \"%s\"\n",
- newval, "SHOW_CONTEXT", "errors");
- pset.show_context = PQSHOW_CONTEXT_ERRORS;
+ PsqlVarEnumError("SHOW_CONTEXT", newval, "never, errors, always");
+ return false;
}
if (pset.db)
PQsetErrorContextVisibility(pset.db, pset.show_context);
+ return true;
}
diff --git a/src/bin/psql/variables.c b/src/bin/psql/variables.c
index 2669572aa7e..91e4ae80953 100644
--- a/src/bin/psql/variables.c
+++ b/src/bin/psql/variables.c
@@ -58,6 +58,11 @@ CreateVariableSpace(void)
return ptr;
}
+/*
+ * Get string value of variable, or NULL if it's not defined.
+ *
+ * Note: result is valid until variable is next assigned to.
+ */
const char *
GetVariable(VariableSpace space, const char *name)
{
@@ -79,94 +84,121 @@ GetVariable(VariableSpace space, const char *name)
}
/*
- * Try to interpret "value" as boolean value.
+ * Try to interpret "value" as a boolean value, and if successful,
+ * store it in *result. Otherwise don't clobber *result.
*
* Valid values are: true, false, yes, no, on, off, 1, 0; as well as unique
* prefixes thereof.
*
* "name" is the name of the variable we're assigning to, to use in error
* report if any. Pass name == NULL to suppress the error report.
+ *
+ * Return true when "value" is syntactically valid, false otherwise.
*/
bool
-ParseVariableBool(const char *value, const char *name)
+ParseVariableBool(const char *value, const char *name, bool *result)
{
size_t len;
+ bool valid = true;
if (value == NULL)
- return false; /* not set -> assume "off" */
+ {
+ *result = false; /* not set -> assume "off" */
+ return valid;
+ }
len = strlen(value);
- if (pg_strncasecmp(value, "true", len) == 0)
- return true;
- else if (pg_strncasecmp(value, "false", len) == 0)
- return false;
- else if (pg_strncasecmp(value, "yes", len) == 0)
- return true;
- else if (pg_strncasecmp(value, "no", len) == 0)
- return false;
+ if (len > 0 && pg_strncasecmp(value, "true", len) == 0)
+ *result = true;
+ else if (len > 0 && pg_strncasecmp(value, "false", len) == 0)
+ *result = false;
+ else if (len > 0 && pg_strncasecmp(value, "yes", len) == 0)
+ *result = true;
+ else if (len > 0 && pg_strncasecmp(value, "no", len) == 0)
+ *result = false;
/* 'o' is not unique enough */
else if (pg_strncasecmp(value, "on", (len > 2 ? len : 2)) == 0)
- return true;
+ *result = true;
else if (pg_strncasecmp(value, "off", (len > 2 ? len : 2)) == 0)
- return false;
+ *result = false;
else if (pg_strcasecmp(value, "1") == 0)
- return true;
+ *result = true;
else if (pg_strcasecmp(value, "0") == 0)
- return false;
+ *result = false;
else
{
- /* NULL is treated as false, so a non-matching value is 'true' */
+ /* string is not recognized; don't clobber *result */
if (name)
- psql_error("unrecognized value \"%s\" for \"%s\"; assuming \"%s\"\n",
- value, name, "on");
- return true;
+ psql_error("unrecognized value \"%s\" for \"%s\": boolean expected\n",
+ value, name);
+ valid = false;
}
+ return valid;
}
-
/*
- * Read numeric variable, or defaultval if it is not set, or faultval if its
- * value is not a valid numeric string. If allowtrail is false, this will
- * include the case where there are trailing characters after the number.
+ * Try to interpret "value" as an integer value, and if successful,
+ * store it in *result. Otherwise don't clobber *result.
+ *
+ * "name" is the name of the variable we're assigning to, to use in error
+ * report if any. Pass name == NULL to suppress the error report.
+ *
+ * Return true when "value" is syntactically valid, false otherwise.
*/
-int
-ParseVariableNum(const char *val,
- int defaultval,
- int faultval,
- bool allowtrail)
+bool
+ParseVariableNum(const char *value, const char *name, int *result)
{
- int result;
+ char *end;
+ long numval;
- if (!val)
- result = defaultval;
- else if (!val[0])
- result = faultval;
+ if (value == NULL)
+ return false;
+ errno = 0;
+ numval = strtol(value, &end, 0);
+ if (errno == 0 && *end == '\0' && end != value && numval == (int) numval)
+ {
+ *result = (int) numval;
+ return true;
+ }
else
{
- char *end;
-
- result = strtol(val, &end, 0);
- if (!allowtrail && *end)
- result = faultval;
+ /* string is not recognized; don't clobber *result */
+ if (name)
+ psql_error("invalid value \"%s\" for \"%s\": integer expected\n",
+ value, name);
+ return false;
}
-
- return result;
}
+/*
+ * Read integer value of the numeric variable named "name".
+ *
+ * Return defaultval if it is not set, or faultval if its value is not a
+ * valid integer. (No error message is issued.)
+ */
int
GetVariableNum(VariableSpace space,
const char *name,
int defaultval,
- int faultval,
- bool allowtrail)
+ int faultval)
{
const char *val;
+ int result;
val = GetVariable(space, name);
- return ParseVariableNum(val, defaultval, faultval, allowtrail);
+ if (!val)
+ return defaultval;
+
+ if (ParseVariableNum(val, NULL, &result))
+ return result;
+ else
+ return faultval;
}
+/*
+ * Print values of all variables.
+ */
void
PrintVariables(VariableSpace space)
{
@@ -184,17 +216,28 @@ PrintVariables(VariableSpace space)
}
}
+/*
+ * Set the variable named "name" to value "value",
+ * or delete it if "value" is NULL.
+ *
+ * Returns true if successful, false if not; in the latter case a suitable
+ * error message has been printed, except for the unexpected case of
+ * space or name being NULL.
+ */
bool
SetVariable(VariableSpace space, const char *name, const char *value)
{
struct _variable *current,
*previous;
- if (!space)
+ if (!space || !name)
return false;
if (!valid_variable_name(name))
+ {
+ psql_error("invalid variable name: \"%s\"\n", name);
return false;
+ }
if (!value)
return DeleteVariable(space, name);
@@ -205,13 +248,30 @@ SetVariable(VariableSpace space, const char *name, const char *value)
{
if (strcmp(current->name, name) == 0)
{
- /* found entry, so update */
- if (current->value)
- free(current->value);
- current->value = pg_strdup(value);
+ /*
+ * Found entry, so update, unless hook returns false. The hook
+ * may need the passed value to have the same lifespan as the
+ * variable, so allocate it right away, even though we'll have to
+ * free it again if the hook returns false.
+ */
+ char *new_value = pg_strdup(value);
+ bool confirmed;
+
if (current->assign_hook)
- (*current->assign_hook) (current->value);
- return true;
+ confirmed = (*current->assign_hook) (new_value);
+ else
+ confirmed = true;
+
+ if (confirmed)
+ {
+ if (current->value)
+ pg_free(current->value);
+ current->value = new_value;
+ }
+ else
+ pg_free(new_value); /* current->value is left unchanged */
+
+ return confirmed;
}
}
@@ -226,19 +286,29 @@ SetVariable(VariableSpace space, const char *name, const char *value)
}
/*
- * This both sets a hook function, and calls it on the current value (if any)
+ * Attach an assign hook function to the named variable.
+ *
+ * If the variable doesn't already exist, create it with value NULL,
+ * just so we have a place to store the hook function. (Externally,
+ * this isn't different from it not being defined.)
+ *
+ * The hook is immediately called on the variable's current value. This is
+ * meant to let it update any derived psql state. If the hook doesn't like
+ * the current value, it will print a message to that effect, but we'll ignore
+ * it. Generally we do not expect any such failure here, because this should
+ * get called before any user-supplied value is assigned.
*/
-bool
+void
SetVariableAssignHook(VariableSpace space, const char *name, VariableAssignHook hook)
{
struct _variable *current,
*previous;
- if (!space)
- return false;
+ if (!space || !name)
+ return;
if (!valid_variable_name(name))
- return false;
+ return;
for (previous = space, current = space->next;
current;
@@ -248,8 +318,8 @@ SetVariableAssignHook(VariableSpace space, const char *name, VariableAssignHook
{
/* found entry, so update */
current->assign_hook = hook;
- (*hook) (current->value);
- return true;
+ (void) (*hook) (current->value);
+ return;
}
}
@@ -260,16 +330,24 @@ SetVariableAssignHook(VariableSpace space, const char *name, VariableAssignHook
current->assign_hook = hook;
current->next = NULL;
previous->next = current;
- (*hook) (NULL);
- return true;
+ (void) (*hook) (NULL);
}
+/*
+ * Convenience function to set a variable's value to "on".
+ */
bool
SetVariableBool(VariableSpace space, const char *name)
{
return SetVariable(space, name, "on");
}
+/*
+ * Attempt to delete variable.
+ *
+ * If unsuccessful, print a message and return "false".
+ * Deleting a nonexistent variable is not an error.
+ */
bool
DeleteVariable(VariableSpace space, const char *name)
{
@@ -277,7 +355,7 @@ DeleteVariable(VariableSpace space, const char *name)
*previous;
if (!space)
- return false;
+ return true;
for (previous = space, current = space->next;
current;
@@ -285,14 +363,21 @@ DeleteVariable(VariableSpace space, const char *name)
{
if (strcmp(current->name, name) == 0)
{
- if (current->value)
- free(current->value);
- current->value = NULL;
- /* Physically delete only if no hook function to remember */
if (current->assign_hook)
- (*current->assign_hook) (NULL);
+ {
+ /* Allow deletion only if hook is okay with NULL value */
+ if (!(*current->assign_hook) (NULL))
+ return false; /* message printed by hook */
+ if (current->value)
+ free(current->value);
+ current->value = NULL;
+ /* Don't delete entry, or we'd forget the hook function */
+ }
else
{
+ /* We can delete the entry as well as its value */
+ if (current->value)
+ free(current->value);
previous->next = current->next;
free(current->name);
free(current);
@@ -303,3 +388,16 @@ DeleteVariable(VariableSpace space, const char *name)
return true;
}
+
+/*
+ * Emit error with suggestions for variables or commands
+ * accepting enum-style arguments.
+ * This function just exists to standardize the wording.
+ * suggestions should follow the format "fee, fi, fo, fum".
+ */
+void
+PsqlVarEnumError(const char *name, const char *value, const char *suggestions)
+{
+ psql_error("unrecognized value \"%s\" for \"%s\"\nAvailable values are: %s.\n",
+ value, name, suggestions);
+}
diff --git a/src/bin/psql/variables.h b/src/bin/psql/variables.h
index d235b1798e4..274b4af5537 100644
--- a/src/bin/psql/variables.h
+++ b/src/bin/psql/variables.h
@@ -3,25 +3,39 @@
*
* Copyright (c) 2000-2017, PostgreSQL Global Development Group
*
+ * This implements a sort of variable repository. One could also think of it
+ * as a cheap version of an associative array. Each variable has a string
+ * name and a string value. The value can't be NULL, or more precisely
+ * that's not distinguishable from the variable being unset.
+ *
* src/bin/psql/variables.h
*/
#ifndef VARIABLES_H
#define VARIABLES_H
/*
- * This implements a sort of variable repository. One could also think of it
- * as a cheap version of an associative array. In each one of these
- * datastructures you can store name/value pairs. There can also be an
- * "assign hook" function that is called whenever the variable's value is
- * changed.
+ * Variables can be given "assign hook" functions. The assign hook can
+ * prevent invalid values from being assigned, and can update internal C
+ * variables to keep them in sync with the variable's current value.
+ *
+ * A hook function is called before any attempted assignment, with the
+ * proposed new value of the variable (or with NULL, if an \unset is being
+ * attempted). If it returns false, the assignment doesn't occur --- it
+ * should print an error message with psql_error() to tell the user why.
*
- * An "unset" operation causes the hook to be called with newval == NULL.
+ * When a hook function is installed with SetVariableAssignHook(), it is
+ * called with the variable's current value (or with NULL, if it wasn't set
+ * yet). But its return value is ignored in this case. The hook should be
+ * set before any possibly-invalid value can be assigned.
+ */
+typedef bool (*VariableAssignHook) (const char *newval);
+
+/*
+ * Data structure representing one variable.
*
* Note: if value == NULL then the variable is logically unset, but we are
* keeping the struct around so as not to forget about its hook function.
*/
-typedef void (*VariableAssignHook) (const char *newval);
-
struct _variable
{
char *name;
@@ -30,27 +44,31 @@ struct _variable
struct _variable *next;
};
+/* Data structure representing a set of variables */
typedef struct _variable *VariableSpace;
+
VariableSpace CreateVariableSpace(void);
const char *GetVariable(VariableSpace space, const char *name);
-bool ParseVariableBool(const char *value, const char *name);
-int ParseVariableNum(const char *val,
- int defaultval,
- int faultval,
- bool allowtrail);
+bool ParseVariableBool(const char *value, const char *name,
+ bool *result);
+
+bool ParseVariableNum(const char *value, const char *name,
+ int *result);
+
int GetVariableNum(VariableSpace space,
const char *name,
int defaultval,
- int faultval,
- bool allowtrail);
+ int faultval);
void PrintVariables(VariableSpace space);
bool SetVariable(VariableSpace space, const char *name, const char *value);
-bool SetVariableAssignHook(VariableSpace space, const char *name, VariableAssignHook hook);
+void SetVariableAssignHook(VariableSpace space, const char *name, VariableAssignHook hook);
bool SetVariableBool(VariableSpace space, const char *name);
bool DeleteVariable(VariableSpace space, const char *name);
+void PsqlVarEnumError(const char *name, const char *value, const char *suggestions);
+
#endif /* VARIABLES_H */
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 464436ab3b3..420825aa56d 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -2,6 +2,15 @@
-- Tests for psql features that aren't closely connected to any
-- specific server features
--
+-- \set
+-- fail: invalid name
+\set invalid/name foo
+invalid variable name: "invalid/name"
+-- fail: invalid value for special variable
+\set AUTOCOMMIT foo
+unrecognized value "foo" for "AUTOCOMMIT": boolean expected
+\set FETCH_COUNT foo
+invalid value "foo" for "FETCH_COUNT": integer expected
-- \gset
select 10 as test01, 20 as test02, 'Hello' as test03 \gset pref01_
\echo :pref01_test01 :pref01_test02 :pref01_test03
@@ -9,7 +18,7 @@ select 10 as test01, 20 as test02, 'Hello' as test03 \gset pref01_
-- should fail: bad variable name
select 10 as "bad name"
\gset
-could not set variable "bad name"
+invalid variable name: "bad name"
-- multiple backslash commands in one line
select 1 as x, 2 as y \gset pref01_ \\ \echo :pref01_x
1
diff --git a/src/test/regress/sql/psql.sql b/src/test/regress/sql/psql.sql
index 900aa7ee1e5..79624b9193a 100644
--- a/src/test/regress/sql/psql.sql
+++ b/src/test/regress/sql/psql.sql
@@ -3,6 +3,14 @@
-- specific server features
--
+-- \set
+
+-- fail: invalid name
+\set invalid/name foo
+-- fail: invalid value for special variable
+\set AUTOCOMMIT foo
+\set FETCH_COUNT foo
+
-- \gset
select 10 as test01, 20 as test02, 'Hello' as test03 \gset pref01_
--
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