1/*
2 * psql - the PostgreSQL interactive terminal
3 *
4 * Copyright (c) 2000-2019, 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#ifdef HAVE_UNIX_SOCKETS
16#include <unistd.h>
17#include <netdb.h>
18#endif
19
20#include "common.h"
21#include "input.h"
22#include "prompt.h"
23#include "settings.h"
24
25
26/*--------------------------
27 * get_prompt
28 *
29 * Returns a statically allocated prompt made by interpolating certain
30 * tcsh style escape sequences into pset.vars "PROMPT1|2|3".
31 * (might not be completely multibyte safe)
32 *
33 * Defined interpolations are:
34 * %M - database server "hostname.domainname", "[local]" for AF_UNIX
35 * sockets, "[local:/dir/name]" if not default
36 * %m - like %M, but hostname only (before first dot), or always "[local]"
37 * %p - backend pid
38 * %> - database server port number
39 * %n - database user name
40 * %/ - current database
41 * %~ - like %/ but "~" when database name equals user name
42 * %# - "#" if superuser, ">" otherwise
43 * %R - in prompt1 normally =, or ^ if single line mode,
44 * or a ! if session is not connected to a database;
45 * in prompt2 -, *, ', or ";
46 * in prompt3 nothing
47 * %x - transaction status: empty, *, !, ? (unknown or no connection)
48 * %l - The line number inside the current statement, starting from 1.
49 * %? - the error code of the last query (not yet implemented)
50 * %% - a percent sign
51 *
52 * %[0-9] - the character with the given decimal code
53 * %0[0-7] - the character with the given octal code
54 * %0x[0-9A-Fa-f] - the character with the given hexadecimal code
55 *
56 * %`command` - The result of executing command in /bin/sh with trailing
57 * newline stripped.
58 * %:name: - The value of the psql variable 'name'
59 * (those will not be rescanned for more escape sequences!)
60 *
61 * %[ ... %] - tell readline that the contained text is invisible
62 *
63 * If the application-wide prompts become NULL somehow, the returned string
64 * will be empty (not NULL!).
65 *--------------------------
66 */
67
68char *
69get_prompt(promptStatus_t status, ConditionalStack cstack)
70{
71#define MAX_PROMPT_SIZE 256
72 static char destination[MAX_PROMPT_SIZE + 1];
73 char buf[MAX_PROMPT_SIZE + 1];
74 bool esc = false;
75 const char *p;
76 const char *prompt_string = "? ";
77
78 switch (status)
79 {
80 case PROMPT_READY:
81 prompt_string = pset.prompt1;
82 break;
83
84 case PROMPT_CONTINUE:
85 case PROMPT_SINGLEQUOTE:
86 case PROMPT_DOUBLEQUOTE:
87 case PROMPT_DOLLARQUOTE:
88 case PROMPT_COMMENT:
89 case PROMPT_PAREN:
90 prompt_string = pset.prompt2;
91 break;
92
93 case PROMPT_COPY:
94 prompt_string = pset.prompt3;
95 break;
96 }
97
98 destination[0] = '\0';
99
100 for (p = prompt_string;
101 *p && strlen(destination) < sizeof(destination) - 1;
102 p++)
103 {
104 memset(buf, 0, sizeof(buf));
105 if (esc)
106 {
107 switch (*p)
108 {
109 /* Current database */
110 case '/':
111 if (pset.db)
112 strlcpy(buf, PQdb(pset.db), sizeof(buf));
113 break;
114 case '~':
115 if (pset.db)
116 {
117 const char *var;
118
119 if (strcmp(PQdb(pset.db), PQuser(pset.db)) == 0 ||
120 ((var = getenv("PGDATABASE")) && strcmp(var, PQdb(pset.db)) == 0))
121 strlcpy(buf, "~", sizeof(buf));
122 else
123 strlcpy(buf, PQdb(pset.db), sizeof(buf));
124 }
125 break;
126
127 /* DB server hostname (long/short) */
128 case 'M':
129 case 'm':
130 if (pset.db)
131 {
132 const char *host = PQhost(pset.db);
133
134 /* INET socket */
135 if (host && host[0] && !is_absolute_path(host))
136 {
137 strlcpy(buf, host, sizeof(buf));
138 if (*p == 'm')
139 buf[strcspn(buf, ".")] = '\0';
140 }
141#ifdef HAVE_UNIX_SOCKETS
142 /* UNIX socket */
143 else
144 {
145 if (!host
146 || strcmp(host, DEFAULT_PGSOCKET_DIR) == 0
147 || *p == 'm')
148 strlcpy(buf, "[local]", sizeof(buf));
149 else
150 snprintf(buf, sizeof(buf), "[local:%s]", host);
151 }
152#endif
153 }
154 break;
155 /* DB server port number */
156 case '>':
157 if (pset.db && PQport(pset.db))
158 strlcpy(buf, PQport(pset.db), sizeof(buf));
159 break;
160 /* DB server user name */
161 case 'n':
162 if (pset.db)
163 strlcpy(buf, session_username(), sizeof(buf));
164 break;
165 /* backend pid */
166 case 'p':
167 if (pset.db)
168 {
169 int pid = PQbackendPID(pset.db);
170
171 if (pid)
172 snprintf(buf, sizeof(buf), "%d", pid);
173 }
174 break;
175
176 case '0':
177 case '1':
178 case '2':
179 case '3':
180 case '4':
181 case '5':
182 case '6':
183 case '7':
184 *buf = (char) strtol(p, unconstify(char **, &p), 8);
185 --p;
186 break;
187 case 'R':
188 switch (status)
189 {
190 case PROMPT_READY:
191 if (cstack != NULL && !conditional_active(cstack))
192 buf[0] = '@';
193 else if (!pset.db)
194 buf[0] = '!';
195 else if (!pset.singleline)
196 buf[0] = '=';
197 else
198 buf[0] = '^';
199 break;
200 case PROMPT_CONTINUE:
201 buf[0] = '-';
202 break;
203 case PROMPT_SINGLEQUOTE:
204 buf[0] = '\'';
205 break;
206 case PROMPT_DOUBLEQUOTE:
207 buf[0] = '"';
208 break;
209 case PROMPT_DOLLARQUOTE:
210 buf[0] = '$';
211 break;
212 case PROMPT_COMMENT:
213 buf[0] = '*';
214 break;
215 case PROMPT_PAREN:
216 buf[0] = '(';
217 break;
218 default:
219 buf[0] = '\0';
220 break;
221 }
222 break;
223
224 case 'x':
225 if (!pset.db)
226 buf[0] = '?';
227 else
228 switch (PQtransactionStatus(pset.db))
229 {
230 case PQTRANS_IDLE:
231 buf[0] = '\0';
232 break;
233 case PQTRANS_ACTIVE:
234 case PQTRANS_INTRANS:
235 buf[0] = '*';
236 break;
237 case PQTRANS_INERROR:
238 buf[0] = '!';
239 break;
240 default:
241 buf[0] = '?';
242 break;
243 }
244 break;
245
246 case 'l':
247 snprintf(buf, sizeof(buf), UINT64_FORMAT, pset.stmt_lineno);
248 break;
249
250 case '?':
251 /* not here yet */
252 break;
253
254 case '#':
255 if (is_superuser())
256 buf[0] = '#';
257 else
258 buf[0] = '>';
259 break;
260
261 /* execute command */
262 case '`':
263 {
264 FILE *fd;
265 char *file = pg_strdup(p + 1);
266 int cmdend;
267
268 cmdend = strcspn(file, "`");
269 file[cmdend] = '\0';
270 fd = popen(file, "r");
271 if (fd)
272 {
273 if (fgets(buf, sizeof(buf), fd) == NULL)
274 buf[0] = '\0';
275 pclose(fd);
276 }
277 if (strlen(buf) > 0 && buf[strlen(buf) - 1] == '\n')
278 buf[strlen(buf) - 1] = '\0';
279 free(file);
280 p += cmdend + 1;
281 break;
282 }
283
284 /* interpolate variable */
285 case ':':
286 {
287 char *name;
288 const char *val;
289 int nameend;
290
291 name = pg_strdup(p + 1);
292 nameend = strcspn(name, ":");
293 name[nameend] = '\0';
294 val = GetVariable(pset.vars, name);
295 if (val)
296 strlcpy(buf, val, sizeof(buf));
297 free(name);
298 p += nameend + 1;
299 break;
300 }
301
302 case '[':
303 case ']':
304#if defined(USE_READLINE) && defined(RL_PROMPT_START_IGNORE)
305
306 /*
307 * readline >=4.0 undocumented feature: non-printing
308 * characters in prompt strings must be marked as such, in
309 * order to properly display the line during editing.
310 */
311 buf[0] = (*p == '[') ? RL_PROMPT_START_IGNORE : RL_PROMPT_END_IGNORE;
312 buf[1] = '\0';
313#endif /* USE_READLINE */
314 break;
315
316 default:
317 buf[0] = *p;
318 buf[1] = '\0';
319 break;
320
321 }
322 esc = false;
323 }
324 else if (*p == '%')
325 esc = true;
326 else
327 {
328 buf[0] = *p;
329 buf[1] = '\0';
330 esc = false;
331 }
332
333 if (!esc)
334 strlcat(destination, buf, sizeof(destination));
335 }
336
337 return destination;
338}
339