diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 4e51e90906c558079921f800ffad8ef0acc31e76..b9c8fccde43235b390614c107b64f304b662780d 100644
--- a/doc/src/sgml/ref/psql-ref.sgml
+++ b/doc/src/sgml/ref/psql-ref.sgml
@@ -455,8 +455,8 @@ EOF
any, by an equal sign on the command line. To unset a variable,
leave off the equal sign. To set a variable with an empty value,
use the equal sign but leave off the value. These assignments are
- done during a very early stage of start-up, so variables reserved
- for internal purposes might get overwritten later.
+ done during command line processing, so variables that reflect
+ connection state will get overwritten later.
</para>
</listitem>
</varlistentry>
@@ -2692,7 +2692,7 @@ lo_import 152801
class="parameter">name</replaceable> to <replaceable
class="parameter">value</replaceable>, or if more than one value
is given, to the concatenation of all of them. If only one
- argument is given, the variable is set with an empty value. To
+ argument is given, the variable is set to an empty-string value. To
unset a variable, use the <command>\unset</command> command.
</para>
@@ -2709,9 +2709,11 @@ lo_import 152801
</para>
<para>
- Although you are welcome to set any variable to anything you
- want, <application>psql</application> treats several variables
- as special. They are documented in the section about variables.
+ Certain variables are special, in that they
+ control <application>psql</application>'s behavior or are
+ automatically set to reflect connection state. These variables are
+ documented in <xref linkend="APP-PSQL-variables"
+ endterm="APP-PSQL-variables-title">, below.
</para>
<note>
@@ -2835,6 +2837,14 @@ testdb=> <userinput>\setenv LESS -imx4F</userinput>
Unsets (deletes) the <application>psql</> variable <replaceable
class="parameter">name</replaceable>.
</para>
+
+ <para>
+ Most variables that control <application>psql</application>'s behavior
+ cannot be unset; instead, an <literal>\unset</> command is interpreted
+ as setting them to their default values.
+ See <xref linkend="APP-PSQL-variables"
+ endterm="APP-PSQL-variables-title">, below.
+ </para>
</listitem>
</varlistentry>
@@ -3053,7 +3063,7 @@ bar
<para>
If you call <command>\set</command> without a second argument, the
- variable is set, with an empty string as value. To unset (i.e., delete)
+ variable is set to an empty-string value. To unset (i.e., delete)
a variable, use the command <command>\unset</command>. To show the
values of all variables, call <command>\set</command> without any argument.
</para>
@@ -3082,8 +3092,23 @@ bar
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
- treated variables follows.
+ using such variable names for your own purposes.
+ </para>
+
+ <para>
+ Variables that control <application>psql</application>'s behavior
+ generally cannot be unset or set to invalid values. An <literal>\unset</>
+ command is allowed but is interpreted as setting the variable to its
+ default value. A <literal>\set</> command without a second argument is
+ interpreted as setting the variable to <literal>on</>, for control
+ variables that accept that value, and is rejected for others. Also,
+ control variables that accept the values <literal>on</>
+ and <literal>off</> will also accept other common spellings of Boolean
+ values, such as <literal>true</> and <literal>false</>.
+ </para>
+
+ <para>
+ The specially treated variables are:
</para>
<variablelist>
@@ -3153,7 +3178,7 @@ bar
<para>
The name of the database you are currently connected to. This is
set every time you connect to a database (including program
- start-up), but can be unset.
+ start-up), but can be changed or unset.
</para>
</listitem>
</varlistentry>
@@ -3171,8 +3196,8 @@ bar
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 behavior is <option>-b</option>. If unset, or if set to
- <literal>none</literal>, then no queries are displayed.
+ for this behavior is <option>-b</option>. If set to
+ <literal>none</literal> (the default), then no queries are displayed.
</para>
</listitem>
</varlistentry>
@@ -3187,8 +3212,9 @@ bar
<productname>PostgreSQL</productname> internals and provide
similar functionality in your own programs. (To select this behavior
on program start-up, use the switch <option>-E</option>.) If you set
- the variable to the value <literal>noexec</literal>, the queries are
+ this variable to the value <literal>noexec</literal>, the queries are
just shown but are not actually sent to the server and executed.
+ The default value is <literal>off</>.
</para>
</listitem>
</varlistentry>
@@ -3200,7 +3226,7 @@ bar
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.
+ with <literal>\encoding</>, but it can be changed or unset.
</para>
</listitem>
</varlistentry>
@@ -3209,7 +3235,7 @@ bar
<term><varname>FETCH_COUNT</varname></term>
<listitem>
<para>
- If this variable is set to an integer value > 0,
+ If this variable is set to an integer value greater than zero,
the results of <command>SELECT</command> queries are fetched
and displayed in groups of that many rows, rather than the
default behavior of collecting the entire result set before
@@ -3220,6 +3246,13 @@ bar
Keep in mind that when using this feature, a query might
fail after having already displayed some rows.
</para>
+
+ <para>
+ <varname>FETCH_COUNT</varname> is ignored if it is unset or does not
+ have a positive value. It cannot be set to a value that is not
+ syntactically an integer.
+ </para>
+
<tip>
<para>
Although you can use any output format with this feature,
@@ -3241,7 +3274,7 @@ 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> (the default), all lines
+ set to <literal>none</literal> (the default), all lines
read in interactive mode are saved on the history list.
</para>
<note>
@@ -3257,8 +3290,12 @@ bar
<term><varname>HISTFILE</varname></term>
<listitem>
<para>
- The file name that will be used to store the history list. The default
- value is <filename>~/.psql_history</filename>. For example, putting:
+ The file name that will be used to store the history list. If unset,
+ the file name is taken from the <envar>PSQL_HISTORY</envar>
+ environment variable. If that is not set either, the default
+ is <filename>~/.psql_history</filename>,
+ or <filename>%APPDATA%\postgresql\psql_history</filename> on Windows.
+ For example, putting:
<programlisting>
\set HISTFILE ~/.psql_history- :DBNAME
</programlisting>
@@ -3279,8 +3316,10 @@ bar
<term><varname>HISTSIZE</varname></term>
<listitem>
<para>
- The number of commands to store in the command history. The
- default value is 500.
+ The maximum number of commands to store in the command history.
+ If unset, at most 500 commands are stored by default.
+ If set to a value that is negative or not an integer, no limit is
+ applied.
</para>
<note>
<para>
@@ -3297,7 +3336,7 @@ bar
<para>
The database server host you are currently connected to. This is
set every time you connect to a database (including program
- start-up), but can be unset.
+ start-up), but can be changed or unset.
</para>
</listitem>
</varlistentry>
@@ -3350,7 +3389,7 @@ bar
generates an error, the error is ignored and the transaction
continues. When set to <literal>interactive</>, such errors are only
ignored in interactive sessions, and not when reading script
- files. When unset or set to <literal>off</>, a statement in a
+ files. When set to <literal>off</> (the default), a statement in a
transaction block that generates an error aborts the entire
transaction. The error rollback mode works by issuing an
implicit <command>SAVEPOINT</> for you, just before each command
@@ -3385,7 +3424,7 @@ bar
<para>
The database server port to which you are currently connected.
This is set every time you connect to a database (including
- program start-up), but can be unset.
+ program start-up), but can be changed or unset.
</para>
</listitem>
</varlistentry>
@@ -3458,7 +3497,7 @@ bar
<para>
The database user you are currently connected as. This is set
every time you connect to a database (including program
- start-up), but can be unset.
+ start-up), but can be changed or unset.
</para>
</listitem>
</varlistentry>
@@ -3481,7 +3520,7 @@ bar
<listitem>
<para>
This variable is set at program start-up to
- reflect <application>psql</>'s version. It can be unset or changed.
+ reflect <application>psql</>'s version. It can be changed or unset.
</para>
</listitem>
</varlistentry>
@@ -4015,6 +4054,7 @@ PSQL_EDITOR_LINENUMBER_ARG='--line '
</para>
<para>
The location of the history file can be set explicitly via
+ the <varname>HISTFILE</varname> <application>psql</> variable or
the <envar>PSQL_HISTORY</envar> environment variable.
</para>
</listitem>
diff --git a/src/bin/psql/startup.c b/src/bin/psql/startup.c
index 0574b5bdfb18f01c49afad55e5894d0b8e295dde..a3654e62722cc4201f76078287982f3396b88e96 100644
--- a/src/bin/psql/startup.c
+++ b/src/bin/psql/startup.c
@@ -166,10 +166,8 @@ main(int argc, char *argv[])
SetVariable(pset.vars, "VERSION", PG_VERSION_STR);
- /* Default values for variables */
+ /* Default values for variables (that don't match the result of \unset) */
SetVariableBool(pset.vars, "AUTOCOMMIT");
- SetVariable(pset.vars, "VERBOSITY", "default");
- SetVariable(pset.vars, "SHOW_CONTEXT", "errors");
SetVariable(pset.vars, "PROMPT1", DEFAULT_PROMPT1);
SetVariable(pset.vars, "PROMPT2", DEFAULT_PROMPT2);
SetVariable(pset.vars, "PROMPT3", DEFAULT_PROMPT3);
@@ -578,17 +576,13 @@ parse_psql_options(int argc, char *argv[], struct adhoc_opts * options)
if (!equal_loc)
{
if (!DeleteVariable(pset.vars, value))
- {
- fprintf(stderr, _("%s: could not delete variable \"%s\"\n"),
- pset.progname, value);
- exit(EXIT_FAILURE);
- }
+ exit(EXIT_FAILURE); /* error already printed */
}
else
{
*equal_loc = '\0';
if (!SetVariable(pset.vars, value, equal_loc + 1))
- exit(EXIT_FAILURE);
+ exit(EXIT_FAILURE); /* error already printed */
}
free(value);
@@ -777,11 +771,28 @@ showVersion(void)
/*
- * Assign hooks for psql variables.
+ * Substitute hooks and assign hooks for psql variables.
*
* This isn't an amazingly good place for them, but neither is anywhere else.
*/
+static char *
+bool_substitute_hook(char *newval)
+{
+ if (newval == NULL)
+ {
+ /* "\unset FOO" becomes "\set FOO off" */
+ newval = pg_strdup("off");
+ }
+ else if (newval[0] == '\0')
+ {
+ /* "\set FOO" becomes "\set FOO on" */
+ pg_free(newval);
+ newval = pg_strdup("on");
+ }
+ return newval;
+}
+
static bool
autocommit_hook(const char *newval)
{
@@ -822,12 +833,19 @@ fetch_count_hook(const char *newval)
return true;
}
+static char *
+echo_substitute_hook(char *newval)
+{
+ if (newval == NULL)
+ newval = pg_strdup("none");
+ return newval;
+}
+
static bool
echo_hook(const char *newval)
{
- if (newval == NULL)
- pset.echo = PSQL_ECHO_NONE;
- else if (pg_strcasecmp(newval, "queries") == 0)
+ Assert(newval != NULL); /* else substitute hook messed up */
+ if (pg_strcasecmp(newval, "queries") == 0)
pset.echo = PSQL_ECHO_QUERIES;
else if (pg_strcasecmp(newval, "errors") == 0)
pset.echo = PSQL_ECHO_ERRORS;
@@ -846,9 +864,8 @@ echo_hook(const char *newval)
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)
+ Assert(newval != NULL); /* else substitute hook messed up */
+ if (pg_strcasecmp(newval, "noexec") == 0)
pset.echo_hidden = PSQL_ECHO_HIDDEN_NOEXEC;
else
{
@@ -868,9 +885,8 @@ echo_hidden_hook(const char *newval)
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)
+ Assert(newval != NULL); /* else substitute hook messed up */
+ if (pg_strcasecmp(newval, "interactive") == 0)
pset.on_error_rollback = PSQL_ERROR_ROLLBACK_INTERACTIVE;
else
{
@@ -887,12 +903,19 @@ on_error_rollback_hook(const char *newval)
return true;
}
+static char *
+comp_keyword_case_substitute_hook(char *newval)
+{
+ if (newval == NULL)
+ newval = pg_strdup("preserve-upper");
+ return newval;
+}
+
static bool
comp_keyword_case_hook(const char *newval)
{
- if (newval == NULL)
- pset.comp_case = PSQL_COMP_CASE_PRESERVE_UPPER;
- else if (pg_strcasecmp(newval, "preserve-upper") == 0)
+ Assert(newval != NULL); /* else substitute hook messed up */
+ if (pg_strcasecmp(newval, "preserve-upper") == 0)
pset.comp_case = PSQL_COMP_CASE_PRESERVE_UPPER;
else if (pg_strcasecmp(newval, "preserve-lower") == 0)
pset.comp_case = PSQL_COMP_CASE_PRESERVE_LOWER;
@@ -909,12 +932,19 @@ comp_keyword_case_hook(const char *newval)
return true;
}
+static char *
+histcontrol_substitute_hook(char *newval)
+{
+ if (newval == NULL)
+ newval = pg_strdup("none");
+ return newval;
+}
+
static bool
histcontrol_hook(const char *newval)
{
- if (newval == NULL)
- pset.histcontrol = hctl_none;
- else if (pg_strcasecmp(newval, "ignorespace") == 0)
+ Assert(newval != NULL); /* else substitute hook messed up */
+ if (pg_strcasecmp(newval, "ignorespace") == 0)
pset.histcontrol = hctl_ignorespace;
else if (pg_strcasecmp(newval, "ignoredups") == 0)
pset.histcontrol = hctl_ignoredups;
@@ -952,12 +982,19 @@ prompt3_hook(const char *newval)
return true;
}
+static char *
+verbosity_substitute_hook(char *newval)
+{
+ if (newval == NULL)
+ newval = pg_strdup("default");
+ return newval;
+}
+
static bool
verbosity_hook(const char *newval)
{
- if (newval == NULL)
- pset.verbosity = PQERRORS_DEFAULT;
- else if (pg_strcasecmp(newval, "default") == 0)
+ Assert(newval != NULL); /* else substitute hook messed up */
+ if (pg_strcasecmp(newval, "default") == 0)
pset.verbosity = PQERRORS_DEFAULT;
else if (pg_strcasecmp(newval, "terse") == 0)
pset.verbosity = PQERRORS_TERSE;
@@ -974,12 +1011,19 @@ verbosity_hook(const char *newval)
return true;
}
+static char *
+show_context_substitute_hook(char *newval)
+{
+ if (newval == NULL)
+ newval = pg_strdup("errors");
+ return newval;
+}
+
static bool
show_context_hook(const char *newval)
{
- if (newval == NULL)
- pset.show_context = PQSHOW_CONTEXT_ERRORS;
- else if (pg_strcasecmp(newval, "never") == 0)
+ Assert(newval != NULL); /* else substitute hook messed up */
+ if (pg_strcasecmp(newval, "never") == 0)
pset.show_context = PQSHOW_CONTEXT_NEVER;
else if (pg_strcasecmp(newval, "errors") == 0)
pset.show_context = PQSHOW_CONTEXT_ERRORS;
@@ -1002,20 +1046,52 @@ EstablishVariableSpace(void)
{
pset.vars = CreateVariableSpace();
- SetVariableAssignHook(pset.vars, "AUTOCOMMIT", autocommit_hook);
- SetVariableAssignHook(pset.vars, "ON_ERROR_STOP", on_error_stop_hook);
- SetVariableAssignHook(pset.vars, "QUIET", quiet_hook);
- SetVariableAssignHook(pset.vars, "SINGLELINE", singleline_hook);
- SetVariableAssignHook(pset.vars, "SINGLESTEP", singlestep_hook);
- SetVariableAssignHook(pset.vars, "FETCH_COUNT", fetch_count_hook);
- SetVariableAssignHook(pset.vars, "ECHO", echo_hook);
- SetVariableAssignHook(pset.vars, "ECHO_HIDDEN", echo_hidden_hook);
- SetVariableAssignHook(pset.vars, "ON_ERROR_ROLLBACK", on_error_rollback_hook);
- SetVariableAssignHook(pset.vars, "COMP_KEYWORD_CASE", comp_keyword_case_hook);
- SetVariableAssignHook(pset.vars, "HISTCONTROL", histcontrol_hook);
- SetVariableAssignHook(pset.vars, "PROMPT1", prompt1_hook);
- SetVariableAssignHook(pset.vars, "PROMPT2", prompt2_hook);
- SetVariableAssignHook(pset.vars, "PROMPT3", prompt3_hook);
- SetVariableAssignHook(pset.vars, "VERBOSITY", verbosity_hook);
- SetVariableAssignHook(pset.vars, "SHOW_CONTEXT", show_context_hook);
+ SetVariableHooks(pset.vars, "AUTOCOMMIT",
+ bool_substitute_hook,
+ autocommit_hook);
+ SetVariableHooks(pset.vars, "ON_ERROR_STOP",
+ bool_substitute_hook,
+ on_error_stop_hook);
+ SetVariableHooks(pset.vars, "QUIET",
+ bool_substitute_hook,
+ quiet_hook);
+ SetVariableHooks(pset.vars, "SINGLELINE",
+ bool_substitute_hook,
+ singleline_hook);
+ SetVariableHooks(pset.vars, "SINGLESTEP",
+ bool_substitute_hook,
+ singlestep_hook);
+ SetVariableHooks(pset.vars, "FETCH_COUNT",
+ NULL,
+ fetch_count_hook);
+ SetVariableHooks(pset.vars, "ECHO",
+ echo_substitute_hook,
+ echo_hook);
+ SetVariableHooks(pset.vars, "ECHO_HIDDEN",
+ bool_substitute_hook,
+ echo_hidden_hook);
+ SetVariableHooks(pset.vars, "ON_ERROR_ROLLBACK",
+ bool_substitute_hook,
+ on_error_rollback_hook);
+ SetVariableHooks(pset.vars, "COMP_KEYWORD_CASE",
+ comp_keyword_case_substitute_hook,
+ comp_keyword_case_hook);
+ SetVariableHooks(pset.vars, "HISTCONTROL",
+ histcontrol_substitute_hook,
+ histcontrol_hook);
+ SetVariableHooks(pset.vars, "PROMPT1",
+ NULL,
+ prompt1_hook);
+ SetVariableHooks(pset.vars, "PROMPT2",
+ NULL,
+ prompt2_hook);
+ SetVariableHooks(pset.vars, "PROMPT3",
+ NULL,
+ prompt3_hook);
+ SetVariableHooks(pset.vars, "VERBOSITY",
+ verbosity_substitute_hook,
+ verbosity_hook);
+ SetVariableHooks(pset.vars, "SHOW_CONTEXT",
+ show_context_substitute_hook,
+ show_context_hook);
}
diff --git a/src/bin/psql/variables.c b/src/bin/psql/variables.c
index 91e4ae8095302237e7ba5133bc6391b07bd61005..b9b8fcb41db1ed07576d101ab73f01b0579481e7 100644
--- a/src/bin/psql/variables.c
+++ b/src/bin/psql/variables.c
@@ -52,6 +52,7 @@ CreateVariableSpace(void)
ptr = pg_malloc(sizeof *ptr);
ptr->name = NULL;
ptr->value = NULL;
+ ptr->substitute_hook = NULL;
ptr->assign_hook = NULL;
ptr->next = NULL;
@@ -101,11 +102,9 @@ ParseVariableBool(const char *value, const char *name, bool *result)
size_t len;
bool valid = true;
+ /* Treat "unset" as an empty string, which will lead to error below */
if (value == NULL)
- {
- *result = false; /* not set -> assume "off" */
- return valid;
- }
+ value = "";
len = strlen(value);
@@ -152,8 +151,10 @@ ParseVariableNum(const char *value, const char *name, int *result)
char *end;
long numval;
+ /* Treat "unset" as an empty string, which will lead to error below */
if (value == NULL)
- return false;
+ value = "";
+
errno = 0;
numval = strtol(value, &end, 0);
if (errno == 0 && *end == '\0' && end != value && numval == (int) numval)
@@ -235,13 +236,13 @@ SetVariable(VariableSpace space, const char *name, const char *value)
if (!valid_variable_name(name))
{
+ /* Deletion of non-existent variable is not an error */
+ if (!value)
+ return true;
psql_error("invalid variable name: \"%s\"\n", name);
return false;
}
- if (!value)
- return DeleteVariable(space, name);
-
for (previous = space, current = space->next;
current;
previous = current, current = current->next)
@@ -249,14 +250,20 @@ SetVariable(VariableSpace space, const char *name, const char *value)
if (strcmp(current->name, name) == 0)
{
/*
- * 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.
+ * Found entry, so update, unless assign hook returns false.
+ *
+ * We must duplicate the passed value to start with. This
+ * simplifies the API for substitute hooks. Moreover, some assign
+ * hooks assume that the passed value has the same lifespan as the
+ * variable. Having to free the string again on failure is a
+ * small price to pay for keeping these APIs simple.
*/
- char *new_value = pg_strdup(value);
+ char *new_value = value ? pg_strdup(value) : NULL;
bool confirmed;
+ if (current->substitute_hook)
+ new_value = (*current->substitute_hook) (new_value);
+
if (current->assign_hook)
confirmed = (*current->assign_hook) (new_value);
else
@@ -267,39 +274,61 @@ SetVariable(VariableSpace space, const char *name, const char *value)
if (current->value)
pg_free(current->value);
current->value = new_value;
+
+ /*
+ * If we deleted the value, and there are no hooks to
+ * remember, we can discard the variable altogether.
+ */
+ if (new_value == NULL &&
+ current->substitute_hook == NULL &&
+ current->assign_hook == NULL)
+ {
+ previous->next = current->next;
+ free(current->name);
+ free(current);
+ }
}
- else
+ else if (new_value)
pg_free(new_value); /* current->value is left unchanged */
return confirmed;
}
}
- /* not present, make new entry */
- current = pg_malloc(sizeof *current);
- current->name = pg_strdup(name);
- current->value = pg_strdup(value);
- current->assign_hook = NULL;
- current->next = NULL;
- previous->next = current;
+ /* not present, make new entry ... unless we were asked to delete */
+ if (value)
+ {
+ current = pg_malloc(sizeof *current);
+ current->name = pg_strdup(name);
+ current->value = pg_strdup(value);
+ current->substitute_hook = NULL;
+ current->assign_hook = NULL;
+ current->next = NULL;
+ previous->next = current;
+ }
return true;
}
/*
- * Attach an assign hook function to the named variable.
+ * Attach substitute and/or assign hook functions to the named variable.
+ * If you need only one hook, pass NULL for the other.
*
- * 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.)
+ * If the variable doesn't already exist, create it with value NULL, just so
+ * we have a place to store the hook function(s). (The substitute hook might
+ * immediately change the NULL to something else; if not, this state is
+ * externally the same as the variable 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.
+ * The substitute hook, if given, is immediately called on the variable's
+ * value. Then the assign hook, if given, is called on the variable's value.
+ * This is meant to let it update any derived psql state. If the assign 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.
*/
void
-SetVariableAssignHook(VariableSpace space, const char *name, VariableAssignHook hook)
+SetVariableHooks(VariableSpace space, const char *name,
+ VariableSubstituteHook shook,
+ VariableAssignHook ahook)
{
struct _variable *current,
*previous;
@@ -317,8 +346,12 @@ SetVariableAssignHook(VariableSpace space, const char *name, VariableAssignHook
if (strcmp(current->name, name) == 0)
{
/* found entry, so update */
- current->assign_hook = hook;
- (void) (*hook) (current->value);
+ current->substitute_hook = shook;
+ current->assign_hook = ahook;
+ if (shook)
+ current->value = (*shook) (current->value);
+ if (ahook)
+ (void) (*ahook) (current->value);
return;
}
}
@@ -327,10 +360,14 @@ SetVariableAssignHook(VariableSpace space, const char *name, VariableAssignHook
current = pg_malloc(sizeof *current);
current->name = pg_strdup(name);
current->value = NULL;
- current->assign_hook = hook;
+ current->substitute_hook = shook;
+ current->assign_hook = ahook;
current->next = NULL;
previous->next = current;
- (void) (*hook) (NULL);
+ if (shook)
+ current->value = (*shook) (current->value);
+ if (ahook)
+ (void) (*ahook) (current->value);
}
/*
@@ -351,42 +388,7 @@ SetVariableBool(VariableSpace space, const char *name)
bool
DeleteVariable(VariableSpace space, const char *name)
{
- struct _variable *current,
- *previous;
-
- if (!space)
- return true;
-
- for (previous = space, current = space->next;
- current;
- previous = current, current = current->next)
- {
- if (strcmp(current->name, name) == 0)
- {
- if (current->assign_hook)
- {
- /* 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);
- }
- return true;
- }
- }
-
- return true;
+ return SetVariable(space, name, NULL);
}
/*
diff --git a/src/bin/psql/variables.h b/src/bin/psql/variables.h
index 274b4af5537ab27ca6d626a35688d4972b09e961..84be7805098b996ac7eaa27b720099b39a2fc9d3 100644
--- a/src/bin/psql/variables.h
+++ b/src/bin/psql/variables.h
@@ -18,28 +18,52 @@
* 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
+ * An assign 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.
*
- * When a hook function is installed with SetVariableAssignHook(), it is
+ * When an assign hook function is installed with SetVariableHooks(), 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);
+/*
+ * Variables can also be given "substitute hook" functions. The substitute
+ * hook can replace values (including NULL) with other values, allowing
+ * normalization of variable contents. For example, for a boolean variable,
+ * we wish to interpret "\unset FOO" as "\set FOO off", and we can do that
+ * by installing a substitute hook. (We can use the same substitute hook
+ * for all bool or nearly-bool variables, which is why this responsibility
+ * isn't part of the assign hook.)
+ *
+ * The substitute hook is called before any attempted assignment, and before
+ * the assign hook if any, passing the proposed new value of the variable as a
+ * malloc'd string (or NULL, if an \unset is being attempted). It can return
+ * the same value, or a different malloc'd string, or modify the string
+ * in-place. It should free the passed-in value if it's not returning it.
+ * The substitute hook generally should not complain about erroneous values;
+ * that's a job for the assign hook.
+ *
+ * When a substitute hook is installed with SetVariableHooks(), it is applied
+ * to the variable's current value (typically NULL, if it wasn't set yet).
+ * That also happens before applying the assign hook.
+ */
+typedef char *(*VariableSubstituteHook) (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.
+ * keeping the struct around so as not to forget about its hook function(s).
*/
struct _variable
{
char *name;
char *value;
+ VariableSubstituteHook substitute_hook;
VariableAssignHook assign_hook;
struct _variable *next;
};
@@ -65,10 +89,13 @@ int GetVariableNum(VariableSpace space,
void PrintVariables(VariableSpace space);
bool SetVariable(VariableSpace space, const char *name, const char *value);
-void SetVariableAssignHook(VariableSpace space, const char *name, VariableAssignHook hook);
bool SetVariableBool(VariableSpace space, const char *name);
bool DeleteVariable(VariableSpace space, const char *name);
+void SetVariableHooks(VariableSpace space, const char *name,
+ VariableSubstituteHook shook,
+ VariableAssignHook ahook);
+
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 420825aa56d9dc9c2bd25203dc33150f008ffc25..026a4f0c83351ff2e397d0ce6c0b2feb8b6b2321 100644
--- a/src/test/regress/expected/psql.out
+++ b/src/test/regress/expected/psql.out
@@ -11,6 +11,23 @@ invalid variable name: "invalid/name"
unrecognized value "foo" for "AUTOCOMMIT": boolean expected
\set FETCH_COUNT foo
invalid value "foo" for "FETCH_COUNT": integer expected
+-- check handling of built-in boolean variable
+\echo :ON_ERROR_ROLLBACK
+off
+\set ON_ERROR_ROLLBACK
+\echo :ON_ERROR_ROLLBACK
+on
+\set ON_ERROR_ROLLBACK foo
+unrecognized value "foo" for "ON_ERROR_ROLLBACK"
+Available values are: on, off, interactive.
+\echo :ON_ERROR_ROLLBACK
+on
+\set ON_ERROR_ROLLBACK on
+\echo :ON_ERROR_ROLLBACK
+on
+\unset ON_ERROR_ROLLBACK
+\echo :ON_ERROR_ROLLBACK
+off
-- \gset
select 10 as test01, 20 as test02, 'Hello' as test03 \gset pref01_
\echo :pref01_test01 :pref01_test02 :pref01_test03
diff --git a/src/test/regress/sql/psql.sql b/src/test/regress/sql/psql.sql
index 79624b9193adeea9a48f1308c5efa9668794f482..d823d11b958b96a60195ceedcd06aba1f3f8711b 100644
--- a/src/test/regress/sql/psql.sql
+++ b/src/test/regress/sql/psql.sql
@@ -10,6 +10,16 @@
-- fail: invalid value for special variable
\set AUTOCOMMIT foo
\set FETCH_COUNT foo
+-- check handling of built-in boolean variable
+\echo :ON_ERROR_ROLLBACK
+\set ON_ERROR_ROLLBACK
+\echo :ON_ERROR_ROLLBACK
+\set ON_ERROR_ROLLBACK foo
+\echo :ON_ERROR_ROLLBACK
+\set ON_ERROR_ROLLBACK on
+\echo :ON_ERROR_ROLLBACK
+\unset ON_ERROR_ROLLBACK
+\echo :ON_ERROR_ROLLBACK
-- \gset