postgresql/src/bin/psql/prompt.c

341 lines
7.4 KiB
C

/*
* psql - the PostgreSQL interactive terminal
*
* Copyright (c) 2000-2019, PostgreSQL Global Development Group
*
* src/bin/psql/prompt.c
*/
#include "postgres_fe.h"
#ifdef WIN32
#include <io.h>
#include <win32.h>
#endif
#ifdef HAVE_UNIX_SOCKETS
#include <unistd.h>
#include <netdb.h>
#endif
#include "common.h"
#include "common/string.h"
#include "input.h"
#include "prompt.h"
#include "settings.h"
/*--------------------------
* get_prompt
*
* Returns a statically allocated prompt made by interpolating certain
* tcsh style escape sequences into pset.vars "PROMPT1|2|3".
* (might not be completely multibyte safe)
*
* Defined interpolations are:
* %M - database server "hostname.domainname", "[local]" for AF_UNIX
* sockets, "[local:/dir/name]" if not default
* %m - like %M, but hostname only (before first dot), or always "[local]"
* %p - backend pid
* %> - database server port number
* %n - database user name
* %/ - current database
* %~ - like %/ but "~" when database name equals user name
* %# - "#" if superuser, ">" otherwise
* %R - in prompt1 normally =, or ^ if single line mode,
* or a ! if session is not connected to a database;
* in prompt2 -, *, ', or ";
* in prompt3 nothing
* %x - transaction status: empty, *, !, ? (unknown or no connection)
* %l - The line number inside the current statement, starting from 1.
* %? - the error code of the last query (not yet implemented)
* %% - a percent sign
*
* %[0-9] - the character with the given decimal code
* %0[0-7] - the character with the given octal code
* %0x[0-9A-Fa-f] - the character with the given hexadecimal code
*
* %`command` - The result of executing command in /bin/sh with trailing
* newline stripped.
* %:name: - The value of the psql variable 'name'
* (those will not be rescanned for more escape sequences!)
*
* %[ ... %] - tell readline that the contained text is invisible
*
* If the application-wide prompts become NULL somehow, the returned string
* will be empty (not NULL!).
*--------------------------
*/
char *
get_prompt(promptStatus_t status, ConditionalStack cstack)
{
#define MAX_PROMPT_SIZE 256
static char destination[MAX_PROMPT_SIZE + 1];
char buf[MAX_PROMPT_SIZE + 1];
bool esc = false;
const char *p;
const char *prompt_string = "? ";
switch (status)
{
case PROMPT_READY:
prompt_string = pset.prompt1;
break;
case PROMPT_CONTINUE:
case PROMPT_SINGLEQUOTE:
case PROMPT_DOUBLEQUOTE:
case PROMPT_DOLLARQUOTE:
case PROMPT_COMMENT:
case PROMPT_PAREN:
prompt_string = pset.prompt2;
break;
case PROMPT_COPY:
prompt_string = pset.prompt3;
break;
}
destination[0] = '\0';
for (p = prompt_string;
*p && strlen(destination) < sizeof(destination) - 1;
p++)
{
memset(buf, 0, sizeof(buf));
if (esc)
{
switch (*p)
{
/* Current database */
case '/':
if (pset.db)
strlcpy(buf, PQdb(pset.db), sizeof(buf));
break;
case '~':
if (pset.db)
{
const char *var;
if (strcmp(PQdb(pset.db), PQuser(pset.db)) == 0 ||
((var = getenv("PGDATABASE")) && strcmp(var, PQdb(pset.db)) == 0))
strlcpy(buf, "~", sizeof(buf));
else
strlcpy(buf, PQdb(pset.db), sizeof(buf));
}
break;
/* DB server hostname (long/short) */
case 'M':
case 'm':
if (pset.db)
{
const char *host = PQhost(pset.db);
/* INET socket */
if (host && host[0] && !is_absolute_path(host))
{
strlcpy(buf, host, sizeof(buf));
if (*p == 'm')
buf[strcspn(buf, ".")] = '\0';
}
#ifdef HAVE_UNIX_SOCKETS
/* UNIX socket */
else
{
if (!host
|| strcmp(host, DEFAULT_PGSOCKET_DIR) == 0
|| *p == 'm')
strlcpy(buf, "[local]", sizeof(buf));
else
snprintf(buf, sizeof(buf), "[local:%s]", host);
}
#endif
}
break;
/* DB server port number */
case '>':
if (pset.db && PQport(pset.db))
strlcpy(buf, PQport(pset.db), sizeof(buf));
break;
/* DB server user name */
case 'n':
if (pset.db)
strlcpy(buf, session_username(), sizeof(buf));
break;
/* backend pid */
case 'p':
if (pset.db)
{
int pid = PQbackendPID(pset.db);
if (pid)
snprintf(buf, sizeof(buf), "%d", pid);
}
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
*buf = (char) strtol(p, unconstify(char **, &p), 8);
--p;
break;
case 'R':
switch (status)
{
case PROMPT_READY:
if (cstack != NULL && !conditional_active(cstack))
buf[0] = '@';
else if (!pset.db)
buf[0] = '!';
else if (!pset.singleline)
buf[0] = '=';
else
buf[0] = '^';
break;
case PROMPT_CONTINUE:
buf[0] = '-';
break;
case PROMPT_SINGLEQUOTE:
buf[0] = '\'';
break;
case PROMPT_DOUBLEQUOTE:
buf[0] = '"';
break;
case PROMPT_DOLLARQUOTE:
buf[0] = '$';
break;
case PROMPT_COMMENT:
buf[0] = '*';
break;
case PROMPT_PAREN:
buf[0] = '(';
break;
default:
buf[0] = '\0';
break;
}
break;
case 'x':
if (!pset.db)
buf[0] = '?';
else
switch (PQtransactionStatus(pset.db))
{
case PQTRANS_IDLE:
buf[0] = '\0';
break;
case PQTRANS_ACTIVE:
case PQTRANS_INTRANS:
buf[0] = '*';
break;
case PQTRANS_INERROR:
buf[0] = '!';
break;
default:
buf[0] = '?';
break;
}
break;
case 'l':
snprintf(buf, sizeof(buf), UINT64_FORMAT, pset.stmt_lineno);
break;
case '?':
/* not here yet */
break;
case '#':
if (is_superuser())
buf[0] = '#';
else
buf[0] = '>';
break;
/* execute command */
case '`':
{
FILE *fd;
char *file = pg_strdup(p + 1);
int cmdend;
cmdend = strcspn(file, "`");
file[cmdend] = '\0';
fd = popen(file, "r");
if (fd)
{
if (fgets(buf, sizeof(buf), fd) == NULL)
buf[0] = '\0';
pclose(fd);
}
/* strip trailing newline and carriage return */
(void) pg_strip_crlf(buf);
free(file);
p += cmdend + 1;
break;
}
/* interpolate variable */
case ':':
{
char *name;
const char *val;
int nameend;
name = pg_strdup(p + 1);
nameend = strcspn(name, ":");
name[nameend] = '\0';
val = GetVariable(pset.vars, name);
if (val)
strlcpy(buf, val, sizeof(buf));
free(name);
p += nameend + 1;
break;
}
case '[':
case ']':
#if defined(USE_READLINE) && defined(RL_PROMPT_START_IGNORE)
/*
* readline >=4.0 undocumented feature: non-printing
* characters in prompt strings must be marked as such, in
* order to properly display the line during editing.
*/
buf[0] = (*p == '[') ? RL_PROMPT_START_IGNORE : RL_PROMPT_END_IGNORE;
buf[1] = '\0';
#endif /* USE_READLINE */
break;
default:
buf[0] = *p;
buf[1] = '\0';
break;
}
esc = false;
}
else if (*p == '%')
esc = true;
else
{
buf[0] = *p;
buf[1] = '\0';
esc = false;
}
if (!esc)
strlcat(destination, buf, sizeof(destination));
}
return destination;
}