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/strbuf.h"
52 #include <sys/select.h>
54 #include <stdio.h>
55 #include <stdlib.h>
57 #include <string.h>
59 #include <termios.h>
60 #include <unistd.h>
62 #if HAVE_EDITLINE_READLINE_H
63 # include <editline/readline.h>
64 # if HAVE_EDITLINE_HISTORY_H
65 # include <editline/history.h>
66 # endif
67 #elif HAVE_READLINE_READLINE_H
68 # include <readline/readline.h>
69 # if HAVE_READLINE_HISTORY_H
70 # include <readline/history.h>
71 # endif
72 #elif HAVE_READLINE_H
73 # include <readline.h>
74 # if HAVE_HISTORY_H
75 # include <history.h>
76 # endif
77 #endif /* READLINEs */
79 extern int yylex(void);
81 /*
82 * public variables
83 */
85 sdb_input_t *sysdb_input = NULL;
87 /*
88 * private variables
89 */
91 static struct termios orig_term_attrs;
93 /*
94 * private helper functions
95 */
97 static void
98 reset_term_attrs(void)
99 {
100 tcsetattr(STDIN_FILENO, TCSANOW, &orig_term_attrs);
101 } /* reset_term_attrs */
103 static void
104 term_rawmode(void)
105 {
106 struct termios attrs;
108 /* setup terminal to operate in non-canonical mode
109 * and single character input */
110 memset(&orig_term_attrs, 0, sizeof(orig_term_attrs));
111 tcgetattr(STDIN_FILENO, &orig_term_attrs);
112 atexit(reset_term_attrs);
114 memset(&attrs, 0, sizeof(attrs));
115 tcgetattr(STDIN_FILENO, &attrs);
116 attrs.c_lflag &= (tcflag_t)(~ICANON);
117 attrs.c_cc[VMIN] = 1;
118 tcsetattr(STDIN_FILENO, TCSANOW, &attrs);
119 } /* term_rawmode */
121 static void
122 handle_input(char *line)
123 {
124 if (! line) {
125 sysdb_input->eof = 1;
126 return;
127 }
129 sdb_strbuf_append(sysdb_input->input, line);
130 sdb_strbuf_append(sysdb_input->input, "\n");
131 free(line);
133 rl_callback_handler_remove();
134 } /* handle_input */
136 /* wait for a new line of data to be available */
137 static ssize_t
138 input_readline(void)
139 {
140 size_t len;
142 fd_set fds;
143 int client_fd;
145 const char *prompt = "sysdb=> ";
147 if (sysdb_input->query_len)
148 prompt = "sysdb-> ";
150 rl_callback_handler_install(prompt, handle_input);
151 client_fd = sdb_client_sockfd(sysdb_input->client);
153 len = sdb_strbuf_len(sysdb_input->input);
154 while ((sdb_strbuf_len(sysdb_input->input) == len)
155 && (! sysdb_input->eof)) {
156 int n;
158 /* XXX: some versions of libedit don't properly reset the terminal in
159 * rl_callback_read_char(); detect those versions */
160 term_rawmode();
162 FD_ZERO(&fds);
163 FD_SET(STDIN_FILENO, &fds);
164 FD_SET(client_fd, &fds);
166 n = select(client_fd + 1, &fds, NULL, NULL, /* timeout = */ NULL);
167 if (n < 0)
168 return (ssize_t)n;
169 else if (! n)
170 continue;
172 /* handle user input with highest priority */
173 if (FD_ISSET(STDIN_FILENO, &fds)) {
174 rl_callback_read_char();
175 continue;
176 }
178 if (! FD_ISSET(client_fd, &fds))
179 continue;
181 /* some response / error message from the server pending */
182 /* XXX: clear current line */
183 printf("\n");
184 sdb_command_print_reply(sysdb_input);
185 rl_forced_update_display();
186 }
188 /* new data available */
189 return (ssize_t)(sdb_strbuf_len(sysdb_input->input) - len);
190 } /* input_readline */
192 /*
193 * public API
194 */
196 int
197 sdb_input_init(sdb_input_t *input)
198 {
199 /* register input handler */
200 sysdb_input = input;
202 if (! isatty(STDIN_FILENO))
203 return -1;
205 term_rawmode();
206 return 0;
207 } /* sdb_input_init */
209 int
210 sdb_input_mainloop(void)
211 {
212 yylex();
213 return 0;
214 } /* sdb_input_mainloop */
216 ssize_t
217 sdb_input_readline(char *buf, int *n_chars, size_t max_chars)
218 {
219 const char *data;
220 size_t len;
222 len = sdb_strbuf_len(sysdb_input->input) - sysdb_input->tokenizer_pos;
224 if (! len) {
225 ssize_t n = input_readline();
226 if (n <= 0) {
227 *n_chars = 0; /* YY_NULL */
228 return n;
229 }
230 len += (size_t)n;
231 }
233 len = (len < max_chars) ? len : max_chars;
234 data = sdb_strbuf_string(sysdb_input->input);
235 data += sysdb_input->tokenizer_pos;
236 strncpy(buf, data, len);
238 sysdb_input->tokenizer_pos += len;
239 *n_chars = (int)len;
240 return (ssize_t)len;
241 } /* sdb_input_readline */
243 int
244 sdb_input_exec_query(void)
245 {
246 char *query = sdb_command_exec(sysdb_input);
248 HIST_ENTRY *current_hist;
249 const char *hist_line = NULL;
251 if (! query)
252 return -1;
254 current_hist = current_history();
255 if (current_hist)
256 hist_line = current_hist->line;
258 if (*query != ' ')
259 if ((! hist_line) || strcmp(hist_line, query))
260 add_history(query);
261 free(query);
262 return 0;
263 } /* sdb_input_exec_query */
265 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */