1 /*
2 * psql - the PostgreSQL interactive terminal
3 *
4 * Copyright (c) 2000-2021, PostgreSQL Global Development Group
5 *
6 * src/bin/psql/prompt.c
7 */
8 #include "postgres_fe.h"
9
10 #ifdef WIN32
11 #include <io.h>
12 #include <win32.h>
13 #endif
14
15 #include "common.h"
16 #include "common/string.h"
17 #include "input.h"
18 #include "libpq/pqcomm.h"
19 #include "prompt.h"
20 #include "settings.h"
21
22 /*--------------------------
23 * get_prompt
24 *
25 * Returns a statically allocated prompt made by interpolating certain
26 * tcsh style escape sequences into pset.vars "PROMPT1|2|3".
27 * (might not be completely multibyte safe)
28 *
29 * Defined interpolations are:
30 * %M - database server "hostname.domainname", "[local]" for AF_UNIX
31 * sockets, "[local:/dir/name]" if not default
32 * %m - like %M, but hostname only (before first dot), or always "[local]"
33 * %p - backend pid
34 * %> - database server port number
35 * %n - database user name
36 * %/ - current database
37 * %~ - like %/ but "~" when database name equals user name
38 * %w - whitespace of the same width as the most recent output of PROMPT1
39 * %# - "#" if superuser, ">" otherwise
40 * %R - in prompt1 normally =, or ^ if single line mode,
41 * or a ! if session is not connected to a database;
42 * in prompt2 -, *, ', or ";
43 * in prompt3 nothing
44 * %x - transaction status: empty, *, !, ? (unknown or no connection)
45 * %l - The line number inside the current statement, starting from 1.
46 * %? - the error code of the last query (not yet implemented)
47 * %% - a percent sign
48 *
49 * %[0-9] - the character with the given decimal code
50 * %0[0-7] - the character with the given octal code
51 * %0x[0-9A-Fa-f] - the character with the given hexadecimal code
52 *
53 * %`command` - The result of executing command in /bin/sh with trailing
54 * newline stripped.
55 * %:name: - The value of the psql variable 'name'
56 * (those will not be rescanned for more escape sequences!)
57 *
58 * %[ ... %] - tell readline that the contained text is invisible
59 *
60 * If the application-wide prompts become NULL somehow, the returned string
61 * will be empty (not NULL!).
62 *--------------------------
63 */
64
65 char *
get_prompt(promptStatus_t status,ConditionalStack cstack)66 get_prompt(promptStatus_t status, ConditionalStack cstack)
67 {
68 #define MAX_PROMPT_SIZE 256
69 static char destination[MAX_PROMPT_SIZE + 1];
70 char buf[MAX_PROMPT_SIZE + 1];
71 bool esc = false;
72 const char *p;
73 const char *prompt_string = "? ";
74 static size_t last_prompt1_width = 0;
75
76 switch (status)
77 {
78 case PROMPT_READY:
79 prompt_string = pset.prompt1;
80 break;
81
82 case PROMPT_CONTINUE:
83 case PROMPT_SINGLEQUOTE:
84 case PROMPT_DOUBLEQUOTE:
85 case PROMPT_DOLLARQUOTE:
86 case PROMPT_COMMENT:
87 case PROMPT_PAREN:
88 prompt_string = pset.prompt2;
89 break;
90
91 case PROMPT_COPY:
92 prompt_string = pset.prompt3;
93 break;
94 }
95
96 destination[0] = '\0';
97
98 for (p = prompt_string;
99 *p && strlen(destination) < sizeof(destination) - 1;
100 p++)
101 {
102 memset(buf, 0, sizeof(buf));
103 if (esc)
104 {
105 switch (*p)
106 {
107 /* Current database */
108 case '/':
109 if (pset.db)
110 strlcpy(buf, PQdb(pset.db), sizeof(buf));
111 break;
112 case '~':
113 if (pset.db)
114 {
115 const char *var;
116
117 if (strcmp(PQdb(pset.db), PQuser(pset.db)) == 0 ||
118 ((var = getenv("PGDATABASE")) && strcmp(var, PQdb(pset.db)) == 0))
119 strlcpy(buf, "~", sizeof(buf));
120 else
121 strlcpy(buf, PQdb(pset.db), sizeof(buf));
122 }
123 break;
124
125 /* Whitespace of the same width as the last PROMPT1 */
126 case 'w':
127 if (pset.db)
128 memset(buf, ' ',
129 Min(last_prompt1_width, sizeof(buf) - 1));
130 break;
131
132 /* DB server hostname (long/short) */
133 case 'M':
134 case 'm':
135 if (pset.db)
136 {
137 const char *host = PQhost(pset.db);
138
139 /* INET socket */
140 if (host && host[0] && !is_unixsock_path(host))
141 {
142 strlcpy(buf, host, sizeof(buf));
143 if (*p == 'm')
144 buf[strcspn(buf, ".")] = '\0';
145 }
146 /* UNIX socket */
147 else
148 {
149 if (!host
150 || strcmp(host, DEFAULT_PGSOCKET_DIR) == 0
151 || *p == 'm')
152 strlcpy(buf, "[local]", sizeof(buf));
153 else
154 snprintf(buf, sizeof(buf), "[local:%s]", host);
155 }
156 }
157 break;
158 /* DB server port number */
159 case '>':
160 if (pset.db && PQport(pset.db))
161 strlcpy(buf, PQport(pset.db), sizeof(buf));
162 break;
163 /* DB server user name */
164 case 'n':
165 if (pset.db)
166 strlcpy(buf, session_username(), sizeof(buf));
167 break;
168 /* backend pid */
169 case 'p':
170 if (pset.db)
171 {
172 int pid = PQbackendPID(pset.db);
173
174 if (pid)
175 snprintf(buf, sizeof(buf), "%d", pid);
176 }
177 break;
178
179 case '0':
180 case '1':
181 case '2':
182 case '3':
183 case '4':
184 case '5':
185 case '6':
186 case '7':
187 *buf = (char) strtol(p, unconstify(char **, &p), 8);
188 --p;
189 break;
190 case 'R':
191 switch (status)
192 {
193 case PROMPT_READY:
194 if (cstack != NULL && !conditional_active(cstack))
195 buf[0] = '@';
196 else if (!pset.db)
197 buf[0] = '!';
198 else if (!pset.singleline)
199 buf[0] = '=';
200 else
201 buf[0] = '^';
202 break;
203 case PROMPT_CONTINUE:
204 buf[0] = '-';
205 break;
206 case PROMPT_SINGLEQUOTE:
207 buf[0] = '\'';
208 break;
209 case PROMPT_DOUBLEQUOTE:
210 buf[0] = '"';
211 break;
212 case PROMPT_DOLLARQUOTE:
213 buf[0] = '$';
214 break;
215 case PROMPT_COMMENT:
216 buf[0] = '*';
217 break;
218 case PROMPT_PAREN:
219 buf[0] = '(';
220 break;
221 default:
222 buf[0] = '\0';
223 break;
224 }
225 break;
226
227 case 'x':
228 if (!pset.db)
229 buf[0] = '?';
230 else
231 switch (PQtransactionStatus(pset.db))
232 {
233 case PQTRANS_IDLE:
234 buf[0] = '\0';
235 break;
236 case PQTRANS_ACTIVE:
237 case PQTRANS_INTRANS:
238 buf[0] = '*';
239 break;
240 case PQTRANS_INERROR:
241 buf[0] = '!';
242 break;
243 default:
244 buf[0] = '?';
245 break;
246 }
247 break;
248
249 case 'l':
250 snprintf(buf, sizeof(buf), UINT64_FORMAT, pset.stmt_lineno);
251 break;
252
253 case '?':
254 /* not here yet */
255 break;
256
257 case '#':
258 if (is_superuser())
259 buf[0] = '#';
260 else
261 buf[0] = '>';
262 break;
263
264 /* execute command */
265 case '`':
266 {
267 int cmdend = strcspn(p + 1, "`");
268 char *file = pnstrdup(p + 1, cmdend);
269 FILE *fd = popen(file, "r");
270
271 if (fd)
272 {
273 if (fgets(buf, sizeof(buf), fd) == NULL)
274 buf[0] = '\0';
275 pclose(fd);
276 }
277
278 /* strip trailing newline and carriage return */
279 (void) pg_strip_crlf(buf);
280
281 free(file);
282 p += cmdend + 1;
283 break;
284 }
285
286 /* interpolate variable */
287 case ':':
288 {
289 int nameend = strcspn(p + 1, ":");
290 char *name = pnstrdup(p + 1, nameend);
291 const char *val;
292
293 val = GetVariable(pset.vars, name);
294 if (val)
295 strlcpy(buf, val, sizeof(buf));
296 free(name);
297 p += nameend + 1;
298 break;
299 }
300
301 case '[':
302 case ']':
303 #if defined(USE_READLINE) && defined(RL_PROMPT_START_IGNORE)
304
305 /*
306 * readline >=4.0 undocumented feature: non-printing
307 * characters in prompt strings must be marked as such, in
308 * order to properly display the line during editing.
309 */
310 buf[0] = (*p == '[') ? RL_PROMPT_START_IGNORE : RL_PROMPT_END_IGNORE;
311 buf[1] = '\0';
312 #endif /* USE_READLINE */
313 break;
314
315 default:
316 buf[0] = *p;
317 buf[1] = '\0';
318 break;
319
320 }
321 esc = false;
322 }
323 else if (*p == '%')
324 esc = true;
325 else
326 {
327 buf[0] = *p;
328 buf[1] = '\0';
329 esc = false;
330 }
331
332 if (!esc)
333 strlcat(destination, buf, sizeof(destination));
334 }
335
336 /* Compute the visible width of PROMPT1, for PROMPT2's %w */
337 if (prompt_string == pset.prompt1)
338 {
339 char *p = destination;
340 char *end = p + strlen(p);
341 bool visible = true;
342
343 last_prompt1_width = 0;
344 while (*p)
345 {
346 #if defined(USE_READLINE) && defined(RL_PROMPT_START_IGNORE)
347 if (*p == RL_PROMPT_START_IGNORE)
348 {
349 visible = false;
350 ++p;
351 }
352 else if (*p == RL_PROMPT_END_IGNORE)
353 {
354 visible = true;
355 ++p;
356 }
357 else
358 #endif
359 {
360 int chlen,
361 chwidth;
362
363 chlen = PQmblen(p, pset.encoding);
364 if (p + chlen > end)
365 break; /* Invalid string */
366
367 if (visible)
368 {
369 chwidth = PQdsplen(p, pset.encoding);
370
371 if (*p == '\n')
372 last_prompt1_width = 0;
373 else if (chwidth > 0)
374 last_prompt1_width += chwidth;
375 }
376
377 p += chlen;
378 }
379 }
380 }
381
382 return destination;
383 }
384