08f639f1ac104c9a8c0527321bc92ba89070e4db
1 /*
2 * SysDB - src/tools/sysdb/input.c
3 * Copyright (C) 2013 Sebastian 'tokkee' Harl <sh@tokkee.org>
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
17 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
22 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
23 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
25 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
28 /*
29 * This module implements the core of the command line tool. It handles all
30 * input from the user and the remote server, interacting with the scanner and
31 * command handling as needed.
32 *
33 * The main loop is managed by the flex scanner which parses the user input.
34 * It will call into this module (using sdb_input_readline()) whenever it
35 * needs further input to continue parsing. Whenever it finds a full query
36 * (terminated by a semicolon), it will hand the query back to this module
37 * (using sdb_input_exec_query()) which will then execute it.
38 *
39 * Most of the process life-time will be spend waiting for input. User input
40 * and (asynchronous) server replies are handled at the same time.
41 */
43 #if HAVE_CONFIG_H
44 # include "config.h"
45 #endif /* HAVE_CONFIG_H */
47 #include "tools/sysdb/input.h"
48 #include "tools/sysdb/command.h"
50 #include "utils/error.h"
51 #include "utils/strbuf.h"
53 #include <errno.h>
55 #include <sys/select.h>
57 #include <stdio.h>
58 #include <stdlib.h>
60 #include <string.h>
62 #include <termios.h>
63 #include <unistd.h>
65 #if HAVE_EDITLINE_READLINE_H
66 # include <editline/readline.h>
67 # if HAVE_EDITLINE_HISTORY_H
68 # include <editline/history.h>
69 # endif
70 #elif HAVE_READLINE_READLINE_H
71 # include <readline/readline.h>
72 # if HAVE_READLINE_HISTORY_H
73 # include <readline/history.h>
74 # endif
75 #elif HAVE_READLINE_H
76 # include <readline.h>
77 # if HAVE_HISTORY_H
78 # include <history.h>
79 # endif
80 #endif /* READLINEs */
82 extern int yylex(void);
84 /*
85 * public variables
86 */
88 sdb_input_t *sysdb_input = NULL;
90 /*
91 * private variables
92 */
94 static struct termios orig_term_attrs;
95 static bool have_orig_term_attrs;
97 /*
98 * private helper functions
99 */
101 static void
102 reset_term_attrs(void)
103 {
104 tcsetattr(STDIN_FILENO, TCSANOW, &orig_term_attrs);
105 } /* reset_term_attrs */
107 static void
108 term_rawmode(void)
109 {
110 struct termios attrs;
112 if (! have_orig_term_attrs) {
113 memset(&orig_term_attrs, 0, sizeof(orig_term_attrs));
114 tcgetattr(STDIN_FILENO, &orig_term_attrs);
115 atexit(reset_term_attrs);
116 have_orig_term_attrs = 1;
117 }
119 /* setup terminal to operate in non-canonical mode
120 * and single character input */
121 memset(&attrs, 0, sizeof(attrs));
122 tcgetattr(STDIN_FILENO, &attrs);
123 attrs.c_lflag &= (tcflag_t)(~ICANON);
124 attrs.c_cc[VMIN] = 1;
125 tcsetattr(STDIN_FILENO, TCSANOW, &attrs);
126 } /* term_rawmode */
128 static void
129 handle_input(char *line)
130 {
131 if (! line) {
132 sysdb_input->eof = 1;
133 return;
134 }
136 if (sdb_client_eof(sysdb_input->client))
137 sdb_input_reconnect();
139 sdb_strbuf_append(sysdb_input->input, "%s\n", line);
140 free(line);
142 if (sysdb_input->interactive)
143 rl_callback_handler_remove();
144 } /* handle_input */
146 /* wait for a new line of data to be available */
147 static ssize_t
148 input_readline(void)
149 {
150 size_t len;
152 fd_set fds;
153 int client_fd;
155 const char *prompt = "sysdb=> ";
157 len = sdb_strbuf_len(sysdb_input->input);
159 if (! sysdb_input->interactive) {
160 char *line = readline("");
161 handle_input(line);
162 return (ssize_t)(sdb_strbuf_len(sysdb_input->input) - len);
163 }
165 if (sysdb_input->query_len)
166 prompt = "sysdb-> ";
167 if (sdb_client_eof(sysdb_input->client))
168 prompt = "!-> ";
170 rl_callback_handler_install(prompt, handle_input);
171 client_fd = sdb_client_sockfd(sysdb_input->client);
172 while ((sdb_strbuf_len(sysdb_input->input) == len)
173 && (! sysdb_input->eof)) {
174 bool connected = !sdb_client_eof(sysdb_input->client);
175 int max_fd, n;
177 /* XXX: some versions of libedit don't properly reset the terminal in
178 * rl_callback_read_char(); detect those versions */
179 term_rawmode();
181 FD_ZERO(&fds);
182 FD_SET(STDIN_FILENO, &fds);
183 max_fd = STDIN_FILENO;
185 if (connected) {
186 FD_SET(client_fd, &fds);
187 if (client_fd > max_fd)
188 max_fd = client_fd;
189 }
191 n = select(max_fd + 1, &fds, NULL, NULL, /* timeout = */ NULL);
192 if (n < 0)
193 return (ssize_t)n;
194 else if (! n)
195 continue;
197 /* handle user input with highest priority */
198 if (FD_ISSET(STDIN_FILENO, &fds)) {
199 rl_callback_read_char();
200 continue;
201 }
203 if ((! connected) || (! FD_ISSET(client_fd, &fds)))
204 continue;
206 /* some response / error message from the server pending */
207 /* XXX: clear current line */
208 printf("\n");
209 sdb_command_print_reply(sysdb_input->client);
211 if (sdb_client_eof(sysdb_input->client)) {
212 rl_callback_handler_remove();
213 /* XXX */
214 printf("Remote side closed the connection.\n");
215 /* return EOF -> restart scanner */
216 return 0;
217 }
218 else
219 rl_forced_update_display();
220 }
222 /* new data available */
223 return (ssize_t)(sdb_strbuf_len(sysdb_input->input) - len);
224 } /* input_readline */
226 /*
227 * public API
228 */
230 int
231 sdb_input_init(sdb_input_t *input)
232 {
233 /* register input handler */
234 sysdb_input = input;
236 input->interactive = isatty(STDIN_FILENO) != 0;
237 errno = 0;
238 if (input->interactive)
239 term_rawmode();
240 return 0;
241 } /* sdb_input_init */
243 int
244 sdb_input_mainloop(void)
245 {
246 while (! sysdb_input->eof)
247 yylex();
248 return 0;
249 } /* sdb_input_mainloop */
251 ssize_t
252 sdb_input_readline(char *buf, size_t *n_chars, size_t max_chars)
253 {
254 const char *data;
255 size_t len;
257 len = sdb_strbuf_len(sysdb_input->input) - sysdb_input->tokenizer_pos;
259 if (! len) {
260 ssize_t n = input_readline();
261 if (n <= 0) {
262 *n_chars = 0; /* YY_NULL */
263 return n;
264 }
265 len += (size_t)n;
266 }
268 len = (len < max_chars) ? len : max_chars;
269 data = sdb_strbuf_string(sysdb_input->input);
270 data += sysdb_input->tokenizer_pos;
271 strncpy(buf, data, len);
273 sysdb_input->tokenizer_pos += len;
274 *n_chars = (int)len;
275 return (ssize_t)len;
276 } /* sdb_input_readline */
278 int
279 sdb_input_exec_query(void)
280 {
281 char *query = sdb_command_exec(sysdb_input);
283 HIST_ENTRY *current_hist;
284 const char *hist_line = NULL;
286 if (! query)
287 return -1;
289 current_hist = current_history();
290 if (current_hist)
291 hist_line = current_hist->line;
293 if (*query != ' ')
294 if ((! hist_line) || strcmp(hist_line, query))
295 add_history(query);
296 free(query);
297 return 0;
298 } /* sdb_input_exec_query */
300 int
301 sdb_input_reconnect(void)
302 {
303 sdb_client_close(sysdb_input->client);
304 if (sdb_client_connect(sysdb_input->client, sysdb_input->user)) {
305 printf("Failed to reconnect to SysDBd.\n");
306 return -1;
307 }
308 printf("Successfully reconnected to SysDBd.\n");
309 return 0;
310 } /* sdb_input_reconnect */
312 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */