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