Branch data Line data Source code
1 : : /*
2 : : * psql - the PostgreSQL interactive terminal
3 : : *
4 : : * Copyright (c) 2000-2026, PostgreSQL Global Development Group
5 : : *
6 : : * src/bin/psql/variables.c
7 : : */
8 : : #include "postgres_fe.h"
9 : :
10 : : #include <math.h>
11 : :
12 : : #include "common.h"
13 : : #include "common/logging.h"
14 : : #include "variables.h"
15 : :
16 : : /*
17 : : * Check whether a variable's name is allowed.
18 : : *
19 : : * We allow any non-ASCII character, as well as ASCII letters, digits, and
20 : : * underscore. Keep this in sync with the definition of variable_char in
21 : : * psqlscan.l and psqlscanslash.l.
22 : : */
23 : : static bool
24 : 358768 : valid_variable_name(const char *name)
25 : : {
26 : 358768 : const unsigned char *ptr = (const unsigned char *) name;
27 : :
28 : : /* Mustn't be zero-length */
29 [ + - ]: 358768 : if (*ptr == '\0')
30 : 0 : return false;
31 : :
32 [ + + ]: 5227774 : while (*ptr)
33 : : {
34 [ + - + + ]: 4869008 : if (IS_HIGHBIT_SET(*ptr) ||
35 : 4869008 : strchr("ABCDEFGHIJKLMNOPQRSTUVWXYZ" "abcdefghijklmnopqrstuvwxyz"
36 : 9738016 : "_0123456789", *ptr) != NULL)
37 : 4869006 : ptr++;
38 : : else
39 : 2 : return false;
40 : : }
41 : :
42 : 358766 : return true;
43 : 358768 : }
44 : :
45 : : /*
46 : : * A "variable space" is represented by an otherwise-unused struct _variable
47 : : * that serves as list header.
48 : : *
49 : : * The list entries are kept in name order (according to strcmp). This
50 : : * is mainly to make the output of PrintVariables() more pleasing.
51 : : */
52 : : VariableSpace
53 : 272 : CreateVariableSpace(void)
54 : : {
55 : 272 : struct _variable *ptr;
56 : :
57 : 272 : ptr = pg_malloc(sizeof *ptr);
58 : 272 : ptr->name = NULL;
59 : 272 : ptr->value = NULL;
60 : 272 : ptr->substitute_hook = NULL;
61 : 272 : ptr->assign_hook = NULL;
62 : 272 : ptr->next = NULL;
63 : :
64 : 544 : return ptr;
65 : 272 : }
66 : :
67 : : /*
68 : : * Get string value of variable, or NULL if it's not defined.
69 : : *
70 : : * Note: result is valid until variable is next assigned to.
71 : : */
72 : : const char *
73 : 588 : GetVariable(VariableSpace space, const char *name)
74 : : {
75 : 588 : struct _variable *current;
76 : :
77 [ + - ]: 588 : if (!space)
78 : 0 : return NULL;
79 : :
80 [ - + ]: 22212 : for (current = space->next; current; current = current->next)
81 : : {
82 : 22212 : int cmp = strcmp(current->name, name);
83 : :
84 [ + + ]: 22212 : if (cmp == 0)
85 : : {
86 : : /* this is correct answer when value is NULL, too */
87 : 505 : return current->value;
88 : : }
89 [ + + ]: 21707 : if (cmp > 0)
90 : 83 : break; /* it's not there */
91 [ + + + ]: 22212 : }
92 : :
93 : 83 : return NULL;
94 : 588 : }
95 : :
96 : : /*
97 : : * Try to interpret "value" as a boolean value, and if successful,
98 : : * store it in *result. Otherwise don't clobber *result.
99 : : *
100 : : * Valid values are: true, false, yes, no, on, off, 1, 0; as well as unique
101 : : * prefixes thereof.
102 : : *
103 : : * "name" is the name of the variable we're assigning to, to use in error
104 : : * report if any. Pass name == NULL to suppress the error report.
105 : : *
106 : : * Return true when "value" is syntactically valid, false otherwise.
107 : : */
108 : : bool
109 : 4207 : ParseVariableBool(const char *value, const char *name, bool *result)
110 : : {
111 : 4207 : size_t len;
112 : 4207 : bool valid = true;
113 : :
114 : : /* Treat "unset" as an empty string, which will lead to error below */
115 [ + - ]: 4207 : if (value == NULL)
116 : 0 : value = "";
117 : :
118 : 4207 : len = strlen(value);
119 : :
120 [ + - + + ]: 4207 : if (len > 0 && pg_strncasecmp(value, "true", len) == 0)
121 : 39 : *result = true;
122 [ + - + + ]: 4168 : else if (len > 0 && pg_strncasecmp(value, "false", len) == 0)
123 : 44 : *result = false;
124 [ + - + + ]: 4124 : else if (len > 0 && pg_strncasecmp(value, "yes", len) == 0)
125 : 1 : *result = true;
126 [ + - + + ]: 4123 : else if (len > 0 && pg_strncasecmp(value, "no", len) == 0)
127 : 1 : *result = false;
128 : : /* 'o' is not unique enough */
129 [ + + + + ]: 4122 : else if (pg_strncasecmp(value, "on", (len > 2 ? len : 2)) == 0)
130 : 1341 : *result = true;
131 [ + + + + ]: 2781 : else if (pg_strncasecmp(value, "off", (len > 2 ? len : 2)) == 0)
132 : 2753 : *result = false;
133 [ + + ]: 28 : else if (pg_strcasecmp(value, "1") == 0)
134 : 24 : *result = true;
135 [ + + ]: 4 : else if (pg_strcasecmp(value, "0") == 0)
136 : 1 : *result = false;
137 : : else
138 : : {
139 : : /* string is not recognized; don't clobber *result */
140 [ + + ]: 3 : if (name)
141 : 2 : pg_log_error("unrecognized value \"%s\" for \"%s\": Boolean expected",
142 : : value, name);
143 : 3 : valid = false;
144 : : }
145 : 8414 : return valid;
146 : 4207 : }
147 : :
148 : : /*
149 : : * Try to interpret "value" as an integer value, and if successful,
150 : : * store it in *result. Otherwise don't clobber *result.
151 : : *
152 : : * "name" is the name of the variable we're assigning to, to use in error
153 : : * report if any. Pass name == NULL to suppress the error report.
154 : : *
155 : : * Return true when "value" is syntactically valid, false otherwise.
156 : : */
157 : : bool
158 : 829 : ParseVariableNum(const char *value, const char *name, int *result)
159 : : {
160 : 829 : char *end;
161 : 829 : long numval;
162 : :
163 : : /* Treat "unset" as an empty string, which will lead to error below */
164 [ + - ]: 829 : if (value == NULL)
165 : 0 : value = "";
166 : :
167 : 829 : errno = 0;
168 : 829 : numval = strtol(value, &end, 0);
169 [ + + + - : 829 : if (errno == 0 && *end == '\0' && end != value && numval == (int) numval)
+ - - + ]
170 : : {
171 : 828 : *result = (int) numval;
172 : 828 : return true;
173 : : }
174 : : else
175 : : {
176 : : /* string is not recognized; don't clobber *result */
177 [ - + ]: 1 : if (name)
178 : 1 : pg_log_error("invalid value \"%s\" for \"%s\": integer expected",
179 : : value, name);
180 : 1 : return false;
181 : : }
182 : 829 : }
183 : :
184 : : /*
185 : : * Try to interpret "value" as a double value, and if successful store it in
186 : : * *result. If unsuccessful, *result isn't clobbered. "name" is the variable
187 : : * which is being assigned, the value of which is only used to produce a good
188 : : * error message. Pass NULL as the name to suppress the error message. The
189 : : * value must be within the range [min,max] in order to be considered valid.
190 : : *
191 : : * Returns true, with *result containing the interpreted value, if "value" is
192 : : * syntactically valid, else false (with *result unchanged).
193 : : */
194 : : bool
195 : 272 : ParseVariableDouble(const char *value, const char *name, double *result, double min, double max)
196 : : {
197 : 272 : char *end;
198 : 272 : double dblval;
199 : :
200 : : /*
201 : : * Empty-string input has historically been treated differently by strtod
202 : : * on various platforms, so handle that by specifically checking for it.
203 : : */
204 [ + - - + ]: 272 : if ((value == NULL) || (*value == '\0'))
205 : : {
206 [ # # ]: 0 : if (name)
207 : 0 : pg_log_error("invalid input syntax for variable \"%s\"", name);
208 : 0 : return false;
209 : : }
210 : :
211 : 272 : errno = 0;
212 : 272 : dblval = strtod(value, &end);
213 [ + - + - : 272 : if (errno == 0 && *end == '\0' && end != value)
- + ]
214 : : {
215 [ - + ]: 272 : if (dblval < min)
216 : : {
217 [ # # ]: 0 : if (name)
218 : 0 : pg_log_error("invalid value \"%s\" for variable \"%s\": must be greater than %.2f",
219 : : value, name, min);
220 : 0 : return false;
221 : : }
222 [ + - ]: 272 : else if (dblval > max)
223 : : {
224 [ # # ]: 0 : if (name)
225 : 0 : pg_log_error("invalid value \"%s\" for variable \"%s\": must be less than %.2f",
226 : : value, name, max);
227 : 0 : }
228 : 272 : *result = dblval;
229 : 272 : return true;
230 : : }
231 : :
232 : : /*
233 : : * Cater for platforms which treat values which aren't zero, but that are
234 : : * too close to zero to have full precision, by checking for zero or real
235 : : * out-of-range values.
236 : : */
237 [ # # # # ]: 0 : else if ((errno == ERANGE) &&
238 [ # # # # ]: 0 : (dblval == 0.0 || dblval >= HUGE_VAL || dblval <= -HUGE_VAL))
239 : : {
240 [ # # ]: 0 : if (name)
241 : 0 : pg_log_error("value \"%s\" is out of range for variable \"%s\"", value, name);
242 : 0 : return false;
243 : : }
244 : : else
245 : : {
246 [ # # ]: 0 : if (name)
247 : 0 : pg_log_error("invalid value \"%s\" for variable \"%s\"", value, name);
248 : 0 : return false;
249 : : }
250 : 272 : }
251 : :
252 : : /*
253 : : * Print values of all variables.
254 : : */
255 : : void
256 : 0 : PrintVariables(VariableSpace space)
257 : : {
258 : 0 : struct _variable *ptr;
259 : :
260 [ # # ]: 0 : if (!space)
261 : 0 : return;
262 : :
263 [ # # ]: 0 : for (ptr = space->next; ptr; ptr = ptr->next)
264 : : {
265 [ # # ]: 0 : if (ptr->value)
266 : 0 : printf("%s = '%s'\n", ptr->name, ptr->value);
267 [ # # ]: 0 : if (cancel_pressed)
268 : 0 : break;
269 : 0 : }
270 [ # # ]: 0 : }
271 : :
272 : : /*
273 : : * Set the variable named "name" to value "value",
274 : : * or delete it if "value" is NULL.
275 : : *
276 : : * Returns true if successful, false if not; in the latter case a suitable
277 : : * error message has been printed, except for the unexpected case of
278 : : * space or name being NULL.
279 : : */
280 : : bool
281 : 352512 : SetVariable(VariableSpace space, const char *name, const char *value)
282 : : {
283 : 352512 : struct _variable *current,
284 : : *previous;
285 : :
286 [ + - - + ]: 352512 : if (!space || !name)
287 : 0 : return false;
288 : :
289 [ + + ]: 352512 : if (!valid_variable_name(name))
290 : : {
291 : : /* Deletion of non-existent variable is not an error */
292 [ - + ]: 2 : if (!value)
293 : 0 : return true;
294 : 2 : pg_log_error("invalid variable name: \"%s\"", name);
295 : 2 : return false;
296 : : }
297 : :
298 [ + + ]: 7803837 : for (previous = space, current = space->next;
299 : 7803837 : current;
300 : 7451327 : previous = current, current = current->next)
301 : : {
302 : 7803738 : int cmp = strcmp(current->name, name);
303 : :
304 [ + + ]: 7803738 : if (cmp == 0)
305 : : {
306 : : /*
307 : : * Found entry, so update, unless assign hook returns false.
308 : : *
309 : : * We must duplicate the passed value to start with. This
310 : : * simplifies the API for substitute hooks. Moreover, some assign
311 : : * hooks assume that the passed value has the same lifespan as the
312 : : * variable. Having to free the string again on failure is a
313 : : * small price to pay for keeping these APIs simple.
314 : : */
315 [ + + ]: 346550 : char *new_value = value ? pg_strdup(value) : NULL;
316 : 346550 : bool confirmed;
317 : :
318 [ + + ]: 346550 : if (current->substitute_hook)
319 : 1657 : new_value = current->substitute_hook(new_value);
320 : :
321 [ + + ]: 346550 : if (current->assign_hook)
322 : 2473 : confirmed = current->assign_hook(new_value);
323 : : else
324 : 344077 : confirmed = true;
325 : :
326 [ + + ]: 346550 : if (confirmed)
327 : : {
328 : 346547 : pg_free(current->value);
329 : 346547 : current->value = new_value;
330 : :
331 : : /*
332 : : * If we deleted the value, and there are no hooks to
333 : : * remember, we can discard the variable altogether.
334 : : */
335 [ + + ]: 346547 : if (new_value == NULL &&
336 [ + - - + ]: 1 : current->substitute_hook == NULL &&
337 : 1 : current->assign_hook == NULL)
338 : : {
339 : 1 : previous->next = current->next;
340 : 1 : free(current->name);
341 : 1 : free(current);
342 : 1 : }
343 : 346547 : }
344 : : else
345 : 3 : pg_free(new_value); /* current->value is left unchanged */
346 : :
347 : 346550 : return confirmed;
348 : 346550 : }
349 [ + + ]: 7457188 : if (cmp > 0)
350 : 5861 : break; /* it's not there */
351 [ + + + ]: 7803738 : }
352 : :
353 : : /* not present, make new entry ... unless we were asked to delete */
354 [ + + ]: 5960 : if (value)
355 : : {
356 : 5329 : current = pg_malloc(sizeof *current);
357 : 5329 : current->name = pg_strdup(name);
358 : 5329 : current->value = pg_strdup(value);
359 : 5329 : current->substitute_hook = NULL;
360 : 5329 : current->assign_hook = NULL;
361 : 5329 : current->next = previous->next;
362 : 5329 : previous->next = current;
363 : 5329 : }
364 : 5960 : return true;
365 : 352512 : }
366 : :
367 : : /*
368 : : * Attach substitute and/or assign hook functions to the named variable.
369 : : * If you need only one hook, pass NULL for the other.
370 : : *
371 : : * If the variable doesn't already exist, create it with value NULL, just so
372 : : * we have a place to store the hook function(s). (The substitute hook might
373 : : * immediately change the NULL to something else; if not, this state is
374 : : * externally the same as the variable not being defined.)
375 : : *
376 : : * The substitute hook, if given, is immediately called on the variable's
377 : : * value. Then the assign hook, if given, is called on the variable's value.
378 : : * This is meant to let it update any derived psql state. If the assign hook
379 : : * doesn't like the current value, it will print a message to that effect,
380 : : * but we'll ignore it. Generally we do not expect any such failure here,
381 : : * because this should get called before any user-supplied value is assigned.
382 : : */
383 : : void
384 : 6256 : SetVariableHooks(VariableSpace space, const char *name,
385 : : VariableSubstituteHook shook,
386 : : VariableAssignHook ahook)
387 : : {
388 : 6256 : struct _variable *current,
389 : : *previous;
390 : :
391 [ + - - + ]: 6256 : if (!space || !name)
392 : 0 : return;
393 : :
394 [ + - ]: 6256 : if (!valid_variable_name(name))
395 : 0 : return;
396 : :
397 [ + + ]: 47600 : for (previous = space, current = space->next;
398 : 47600 : current;
399 : 41344 : previous = current, current = current->next)
400 : : {
401 : 45696 : int cmp = strcmp(current->name, name);
402 : :
403 [ + - ]: 45696 : if (cmp == 0)
404 : : {
405 : : /* found entry, so update */
406 : 0 : current->substitute_hook = shook;
407 : 0 : current->assign_hook = ahook;
408 [ # # ]: 0 : if (shook)
409 : 0 : current->value = (*shook) (current->value);
410 [ # # ]: 0 : if (ahook)
411 : 0 : (void) (*ahook) (current->value);
412 : 0 : return;
413 : : }
414 [ + + ]: 45696 : if (cmp > 0)
415 : 4352 : break; /* it's not there */
416 [ - + + ]: 45696 : }
417 : :
418 : : /* not present, make new entry */
419 : 6256 : current = pg_malloc(sizeof *current);
420 : 6256 : current->name = pg_strdup(name);
421 : 6256 : current->value = NULL;
422 : 6256 : current->substitute_hook = shook;
423 : 6256 : current->assign_hook = ahook;
424 : 6256 : current->next = previous->next;
425 : 6256 : previous->next = current;
426 [ + + ]: 6256 : if (shook)
427 : 5168 : current->value = (*shook) (current->value);
428 [ + - ]: 6256 : if (ahook)
429 : 6256 : (void) (*ahook) (current->value);
430 [ - + ]: 6256 : }
431 : :
432 : : /*
433 : : * Return true iff the named variable has substitute and/or assign hook
434 : : * functions.
435 : : */
436 : : bool
437 : 140 : VariableHasHook(VariableSpace space, const char *name)
438 : : {
439 : 140 : struct _variable *current;
440 : :
441 [ + - ]: 140 : Assert(space);
442 [ + - ]: 140 : Assert(name);
443 : :
444 [ + + ]: 7051 : for (current = space->next; current; current = current->next)
445 : : {
446 : 7007 : int cmp = strcmp(current->name, name);
447 : :
448 [ + + ]: 7007 : if (cmp == 0)
449 [ + + ]: 22 : return (current->substitute_hook != NULL ||
450 : 21 : current->assign_hook != NULL);
451 [ + + ]: 6985 : if (cmp > 0)
452 : 74 : break; /* it's not there */
453 [ + + + ]: 7007 : }
454 : :
455 : 118 : return false;
456 : 140 : }
457 : :
458 : : /*
459 : : * Convenience function to set a variable's value to "on".
460 : : */
461 : : bool
462 : 816 : SetVariableBool(VariableSpace space, const char *name)
463 : : {
464 : 816 : return SetVariable(space, name, "on");
465 : : }
466 : :
467 : : /*
468 : : * Attempt to delete variable.
469 : : *
470 : : * If unsuccessful, print a message and return "false".
471 : : * Deleting a nonexistent variable is not an error.
472 : : */
473 : : bool
474 : 0 : DeleteVariable(VariableSpace space, const char *name)
475 : : {
476 : 0 : return SetVariable(space, name, NULL);
477 : : }
478 : :
479 : : /*
480 : : * Emit error with suggestions for variables or commands
481 : : * accepting enum-style arguments.
482 : : * This function just exists to standardize the wording.
483 : : * suggestions should follow the format "fee, fi, fo, fum".
484 : : */
485 : : void
486 : 1 : PsqlVarEnumError(const char *name, const char *value, const char *suggestions)
487 : : {
488 : 1 : pg_log_error("unrecognized value \"%s\" for \"%s\"\n"
489 : : "Available values are: %s.",
490 : : value, name, suggestions);
491 : 1 : }
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