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;
96 /*
97 * private helper functions
98 */
100 static void
101 reset_term_attrs(void)
102 {
103 tcsetattr(STDIN_FILENO, TCSANOW, &orig_term_attrs);
104 } /* reset_term_attrs */
106 static void
107 term_rawmode(void)
108 {
109 struct termios attrs;
111 /* setup terminal to operate in non-canonical mode
112 * and single character input */
113 memset(&orig_term_attrs, 0, sizeof(orig_term_attrs));
114 tcgetattr(STDIN_FILENO, &orig_term_attrs);
115 atexit(reset_term_attrs);
117 memset(&attrs, 0, sizeof(attrs));
118 tcgetattr(STDIN_FILENO, &attrs);
119 attrs.c_lflag &= (tcflag_t)(~ICANON);
120 attrs.c_cc[VMIN] = 1;
121 tcsetattr(STDIN_FILENO, TCSANOW, &attrs);
122 } /* term_rawmode */
124 static void
125 handle_input(char *line)
126 {
127 if (! line) {
128 sysdb_input->eof = 1;
129 return;
130 }
132 sdb_strbuf_append(sysdb_input->input, "%s\n", line);
133 free(line);
135 if (sysdb_input->interactive)
136 rl_callback_handler_remove();
137 } /* handle_input */
139 /* wait for a new line of data to be available */
140 static ssize_t
141 input_readline(void)
142 {
143 size_t len;
145 fd_set fds;
146 int client_fd;
148 const char *prompt = "sysdb=> ";
150 len = sdb_strbuf_len(sysdb_input->input);
152 if (! sysdb_input->interactive) {
153 char *line = readline("");
154 handle_input(line);
155 return (ssize_t)(sdb_strbuf_len(sysdb_input->input) - len);
156 }
158 if (sysdb_input->query_len)
159 prompt = "sysdb-> ";
161 rl_callback_handler_install(prompt, handle_input);
162 client_fd = sdb_client_sockfd(sysdb_input->client);
163 while ((sdb_strbuf_len(sysdb_input->input) == len)
164 && (! sysdb_input->eof)) {
165 int n;
167 /* XXX: some versions of libedit don't properly reset the terminal in
168 * rl_callback_read_char(); detect those versions */
169 term_rawmode();
171 FD_ZERO(&fds);
172 FD_SET(STDIN_FILENO, &fds);
173 FD_SET(client_fd, &fds);
175 n = select(client_fd + 1, &fds, NULL, NULL, /* timeout = */ NULL);
176 if (n < 0)
177 return (ssize_t)n;
178 else if (! n)
179 continue;
181 /* handle user input with highest priority */
182 if (FD_ISSET(STDIN_FILENO, &fds)) {
183 rl_callback_read_char();
184 continue;
185 }
187 if (! FD_ISSET(client_fd, &fds))
188 continue;
190 if (sdb_client_eof(sysdb_input->client)) {
191 /* XXX: try to reconnect */
192 printf("\n");
193 sdb_log(SDB_LOG_ERR, "Remote side closed the connection.");
194 /* return EOF */
195 return 0;
196 }
198 /* some response / error message from the server pending */
199 /* XXX: clear current line */
200 printf("\n");
201 sdb_command_print_reply(sysdb_input->client);
202 rl_forced_update_display();
203 }
205 /* new data available */
206 return (ssize_t)(sdb_strbuf_len(sysdb_input->input) - len);
207 } /* input_readline */
209 /*
210 * public API
211 */
213 int
214 sdb_input_init(sdb_input_t *input)
215 {
216 /* register input handler */
217 sysdb_input = input;
219 input->interactive = isatty(STDIN_FILENO) != 0;
220 errno = 0;
221 if (input->interactive)
222 term_rawmode();
223 return 0;
224 } /* sdb_input_init */
226 int
227 sdb_input_mainloop(void)
228 {
229 yylex();
230 return 0;
231 } /* sdb_input_mainloop */
233 ssize_t
234 sdb_input_readline(char *buf, size_t *n_chars, size_t max_chars)
235 {
236 const char *data;
237 size_t len;
239 len = sdb_strbuf_len(sysdb_input->input) - sysdb_input->tokenizer_pos;
241 if (! len) {
242 ssize_t n = input_readline();
243 if (n <= 0) {
244 *n_chars = 0; /* YY_NULL */
245 return n;
246 }
247 len += (size_t)n;
248 }
250 len = (len < max_chars) ? len : max_chars;
251 data = sdb_strbuf_string(sysdb_input->input);
252 data += sysdb_input->tokenizer_pos;
253 strncpy(buf, data, len);
255 sysdb_input->tokenizer_pos += len;
256 *n_chars = (int)len;
257 return (ssize_t)len;
258 } /* sdb_input_readline */
260 int
261 sdb_input_exec_query(void)
262 {
263 char *query = sdb_command_exec(sysdb_input);
265 HIST_ENTRY *current_hist;
266 const char *hist_line = NULL;
268 if (! query)
269 return -1;
271 current_hist = current_history();
272 if (current_hist)
273 hist_line = current_hist->line;
275 if (*query != ' ')
276 if ((! hist_line) || strcmp(hist_line, query))
277 add_history(query);
278 free(query);
279 return 0;
280 } /* sdb_input_exec_query */
282 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */