src/tools/sysdb/input.c

   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  */
  27
  28 #if HAVE_CONFIG_H
  29 #       include "config.h"
  30 #endif /* HAVE_CONFIG_H */
  31
  32 #include "tools/sysdb/input.h"
  33 #include "tools/sysdb/command.h"
  34
  35 #include "utils/strbuf.h"
  36
  37 #include <sys/select.h>
  38
  39 #include <stdio.h>
  40 #include <stdlib.h>
  41
  42 #include <string.h>
  43
  44 #include <termios.h>
  45 #include <unistd.h>
  46
  47 #if HAVE_EDITLINE_READLINE_H
  48 #       include <editline/readline.h>
  49 #       if HAVE_EDITLINE_HISTORY_H
  50 #               include <editline/history.h>
  51 #       endif
  52 #elif HAVE_READLINE_READLINE_H
  53 #       include <readline/readline.h>
  54 #       if HAVE_READLINE_HISTORY_H
  55 #               include <readline/history.h>
  56 #       endif
  57 #elif HAVE_READLINE_H
  58 #       include <readline.h>
  59 #       if HAVE_HISTORY_H
  60 #               include <history.h>
  61 #       endif
  62 #endif /* READLINEs */
  63
  64 /*
  65  * public variables
  66  */
  67
  68 sdb_input_t *sysdb_input = NULL;
  69
  70 /*
  71  * private variables
  72  */
  73
  74 static struct termios orig_term_attrs;
  75
  76 /*
  77  * private helper functions
  78  */
  79
  80 static void
  81 reset_term_attrs(void)
  82 {
  83         tcsetattr(STDIN_FILENO, TCSANOW, &orig_term_attrs);
  84 } /* reset_term_attrs */
  85
  86 static void
  87 term_rawmode(void)
  88 {
  89         struct termios attrs;
  90
  91         /* setup terminal to operate in non-canonical mode
  92          * and single character input */
  93         memset(&orig_term_attrs, 0, sizeof(orig_term_attrs));
  94         tcgetattr(STDIN_FILENO, &orig_term_attrs);
  95         atexit(reset_term_attrs);
  96
  97         memset(&attrs, 0, sizeof(attrs));
  98         tcgetattr(STDIN_FILENO, &attrs);
  99         attrs.c_lflag &= (tcflag_t)(~ICANON);
 100         attrs.c_cc[VMIN] = 1;
 101         tcsetattr(STDIN_FILENO, TCSANOW, &attrs);
 102 } /* term_rawmode */
 103
 104 static void
 105 handle_input(char *line)
 106 {
 107         if (! line) {
 108                 sysdb_input->eof = 1;
 109                 return;
 110         }
 111
 112         sdb_strbuf_append(sysdb_input->input, line);
 113         sdb_strbuf_append(sysdb_input->input, "\n");
 114         free(line);
 115
 116         rl_callback_handler_remove();
 117 } /* handle_input */
 118
 119 /* wait for a new line of data to be available */
 120 static ssize_t
 121 input_readline(void)
 122 {
 123         size_t len;
 124
 125         fd_set fds;
 126         int client_fd;
 127
 128         const char *prompt = "sysdb=> ";
 129
 130         if (sysdb_input->query_len)
 131                 prompt = "sysdb-> ";
 132
 133         rl_callback_handler_install(prompt, handle_input);
 134         client_fd = sdb_client_sockfd(sysdb_input->client);
 135
 136         len = sdb_strbuf_len(sysdb_input->input);
 137         while ((sdb_strbuf_len(sysdb_input->input) == len)
 138                         && (! sysdb_input->eof)) {
 139                 int n;
 140
 141                 /* XXX: some versions of libedit don't properly reset the terminal in
 142                  * rl_callback_read_char(); detect those versions */
 143                 term_rawmode();
 144
 145                 FD_ZERO(&fds);
 146                 FD_SET(STDIN_FILENO, &fds);
 147                 FD_SET(client_fd, &fds);
 148
 149                 n = select(client_fd + 1, &fds, NULL, NULL, /* timeout = */ NULL);
 150                 if (n < 0)
 151                         return (ssize_t)n;
 152                 else if (! n)
 153                         continue;
 154
 155                 /* handle user input with highest priority */
 156                 if (FD_ISSET(STDIN_FILENO, &fds)) {
 157                         rl_callback_read_char();
 158                         continue;
 159                 }
 160
 161                 if (! FD_ISSET(client_fd, &fds))
 162                         continue;
 163
 164                 /* some response / error message from the server pending */
 165                 /* XXX: clear current line */
 166                 printf("\n");
 167                 sdb_command_print_reply(sysdb_input);
 168                 rl_forced_update_display();
 169         }
 170
 171         /* new data available */
 172         return (ssize_t)(sdb_strbuf_len(sysdb_input->input) - len);
 173 } /* input_readline */
 174
 175 /*
 176  * public API
 177  */
 178
 179 int
 180 sdb_input_init(sdb_input_t *input)
 181 {
 182         /* register input handler */
 183         sysdb_input = input;
 184
 185         if (! isatty(STDIN_FILENO))
 186                 return -1;
 187
 188         term_rawmode();
 189         return 0;
 190 } /* sdb_input_init */
 191
 192 ssize_t
 193 sdb_input_readline(char *buf, int *n_chars, size_t max_chars)
 194 {
 195         const char *data;
 196         size_t len;
 197
 198         len = sdb_strbuf_len(sysdb_input->input) - sysdb_input->tokenizer_pos;
 199
 200         if (! len) {
 201                 ssize_t n = input_readline();
 202                 if (n <= 0) {
 203                         *n_chars = 0; /* YY_NULL */
 204                         return n;
 205                 }
 206                 len += (size_t)n;
 207         }
 208
 209         len = (len < max_chars) ? len : max_chars;
 210         data = sdb_strbuf_string(sysdb_input->input);
 211         data += sysdb_input->tokenizer_pos;
 212         strncpy(buf, data, len);
 213
 214         sysdb_input->tokenizer_pos += len;
 215         *n_chars = (int)len;
 216         return (ssize_t)len;
 217 } /* sdb_input_readline */
 218
 219 int
 220 sdb_input_exec_query(void)
 221 {
 222         char *query = sdb_command_exec(sysdb_input);
 223
 224         HIST_ENTRY *current_hist;
 225         const char *hist_line = NULL;
 226
 227         if (! query)
 228                 return -1;
 229
 230         current_hist = current_history();
 231         if (current_hist)
 232                 hist_line = current_hist->line;
 233
 234         if (*query != ' ')
 235                 if ((! hist_line) || strcmp(hist_line, query))
 236                         add_history(query);
 237         free(query);
 238         return 0;
 239 } /* sdb_input_exec_query */
 240
 241 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 242