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sprompt.c
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1 /*-------------------------------------------------------------------------
2  *
3  * sprompt.c
4  * simple_prompt() routine
5  *
6  * Portions Copyright (c) 1996-2017, PostgreSQL Global Development Group
7  * Portions Copyright (c) 1994, Regents of the University of California
8  *
9  *
10  * IDENTIFICATION
11  * src/port/sprompt.c
12  *
13  *-------------------------------------------------------------------------
14  */
15 #include "c.h"
16 
17 #ifdef HAVE_TERMIOS_H
18 #include <termios.h>
19 #endif
20 
21 
22 /*
23  * simple_prompt
24  *
25  * Generalized function especially intended for reading in usernames and
26  * passwords interactively. Reads from /dev/tty or stdin/stderr.
27  *
28  * prompt: The prompt to print, or NULL if none (automatically localized)
29  * destination: buffer in which to store result
30  * destlen: allocated length of destination
31  * echo: Set to false if you want to hide what is entered (for passwords)
32  *
33  * The input (without trailing newline) is returned in the destination buffer,
34  * with a '\0' appended.
35  */
36 void
37 simple_prompt(const char *prompt, char *destination, size_t destlen, bool echo)
38 {
39  int length;
40  FILE *termin,
41  *termout;
42 
43 #ifdef HAVE_TERMIOS_H
44  struct termios t_orig,
45  t;
46 #else
47 #ifdef WIN32
48  HANDLE t = NULL;
49  DWORD t_orig = 0;
50 #endif
51 #endif
52 
53 #ifdef WIN32
54 
55  /*
56  * A Windows console has an "input code page" and an "output code page";
57  * these usually match each other, but they rarely match the "Windows ANSI
58  * code page" defined at system boot and expected of "char *" arguments to
59  * Windows API functions. The Microsoft CRT write() implementation
60  * automatically converts text between these code pages when writing to a
61  * console. To identify such file descriptors, it calls GetConsoleMode()
62  * on the underlying HANDLE, which in turn requires GENERIC_READ access on
63  * the HANDLE. Opening termout in mode "w+" allows that detection to
64  * succeed. Otherwise, write() would not recognize the descriptor as a
65  * console, and non-ASCII characters would display incorrectly.
66  *
67  * XXX fgets() still receives text in the console's input code page. This
68  * makes non-ASCII credentials unportable.
69  */
70  termin = fopen("CONIN$", "r");
71  termout = fopen("CONOUT$", "w+");
72 #else
73 
74  /*
75  * Do not try to collapse these into one "w+" mode file. Doesn't work on
76  * some platforms (eg, HPUX 10.20).
77  */
78  termin = fopen("/dev/tty", "r");
79  termout = fopen("/dev/tty", "w");
80 #endif
81  if (!termin || !termout
82 #ifdef WIN32
83 
84  /*
85  * Direct console I/O does not work from the MSYS 1.0.10 console. Writes
86  * reach nowhere user-visible; reads block indefinitely. XXX This affects
87  * most Windows terminal environments, including rxvt, mintty, Cygwin
88  * xterm, Cygwin sshd, and PowerShell ISE. Switch to a more-generic test.
89  */
90  || (getenv("OSTYPE") && strcmp(getenv("OSTYPE"), "msys") == 0)
91 #endif
92  )
93  {
94  if (termin)
95  fclose(termin);
96  if (termout)
97  fclose(termout);
98  termin = stdin;
99  termout = stderr;
100  }
101 
102 #ifdef HAVE_TERMIOS_H
103  if (!echo)
104  {
105  tcgetattr(fileno(termin), &t);
106  t_orig = t;
107  t.c_lflag &= ~ECHO;
108  tcsetattr(fileno(termin), TCSAFLUSH, &t);
109  }
110 #else
111 #ifdef WIN32
112  if (!echo)
113  {
114  /* get a new handle to turn echo off */
115  t = GetStdHandle(STD_INPUT_HANDLE);
116 
117  /* save the old configuration first */
118  GetConsoleMode(t, &t_orig);
119 
120  /* set to the new mode */
121  SetConsoleMode(t, ENABLE_LINE_INPUT | ENABLE_PROCESSED_INPUT);
122  }
123 #endif
124 #endif
125 
126  if (prompt)
127  {
128  fputs(_(prompt), termout);
129  fflush(termout);
130  }
131 
132  if (fgets(destination, destlen, termin) == NULL)
133  destination[0] = '\0';
134 
135  length = strlen(destination);
136  if (length > 0 && destination[length - 1] != '\n')
137  {
138  /* eat rest of the line */
139  char buf[128];
140  int buflen;
141 
142  do
143  {
144  if (fgets(buf, sizeof(buf), termin) == NULL)
145  break;
146  buflen = strlen(buf);
147  } while (buflen > 0 && buf[buflen - 1] != '\n');
148  }
149 
150  if (length > 0 && destination[length - 1] == '\n')
151  /* remove trailing newline */
152  destination[length - 1] = '\0';
153 
154 #ifdef HAVE_TERMIOS_H
155  if (!echo)
156  {
157  tcsetattr(fileno(termin), TCSAFLUSH, &t_orig);
158  fputs("\n", termout);
159  fflush(termout);
160  }
161 #else
162 #ifdef WIN32
163  if (!echo)
164  {
165  /* reset to the original console mode */
166  SetConsoleMode(t, t_orig);
167  fputs("\n", termout);
168  fflush(termout);
169  }
170 #endif
171 #endif
172 
173  if (termin != stdin)
174  {
175  fclose(termin);
176  fclose(termout);
177  }
178 }
int length(const List *list)
Definition: list.c:1271
static char * buf
Definition: pg_test_fsync.c:67
void simple_prompt(const char *prompt, char *destination, size_t destlen, bool echo)
Definition: sprompt.c:37
#define _(x)
Definition: elog.c:84