input.c

   1 /* $OpenBSD: input.c,v 1.2 2012/07/10 10:28:05 nicm Exp $ */
   2
   3 /*
   4  * Copyright (c) 2012 Nicholas Marriott <nicm@openbsd.org>
   5  *
   6  * Permission to use, copy, modify, and distribute this software for any
   7  * purpose with or without fee is hereby granted, provided that the above
   8  * copyright notice and this permission notice appear in all copies.
   9  *
  10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  14  * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
  15  * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
  16  * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  17  */
  18
  19 #include <sys/types.h>
  20
  21 #include <ctype.h>
  22 #include <errno.h>
  23 #include <signal.h>
  24 #include <stdio.h>
  25 #include <string.h>
  26 #include <termios.h>
  27 #include <unistd.h>
  28
  29 #include "cu.h"
  30
  31 /*
  32  * Prompt and read a line of user input from stdin. We want to use the termios
  33  * we were started with so restore and stick in a signal handler for ^C.
  34  */
  35
  36 volatile sig_atomic_t input_stop;
  37
  38 void    input_signal(int);
  39
  40 void
  41 input_signal(int sig __attribute__((unused)))
  42 {
  43         input_stop = 1;
  44 }
  45
  46 const char *
  47 get_input(const char *prompt)
  48 {
  49         static char             s[BUFSIZ];
  50         struct sigaction        act, oact;
  51         char                    c, *cp, *out = NULL;
  52         ssize_t                 n;
  53
  54         memset(&act, 0, sizeof(act));
  55         sigemptyset(&act.sa_mask);
  56         act.sa_flags = 0;
  57         act.sa_handler = input_signal;
  58         if (sigaction(SIGINT, &act, &oact) != 0)
  59                 cu_err(1, "sigaction");
  60         input_stop = 0;
  61
  62         restore_termios();
  63
  64         printf("%s ", prompt);
  65         fflush(stdout);
  66
  67         cp = s;
  68         while (cp != s + sizeof(s) - 1) {
  69                 n = read(STDIN_FILENO, &c, 1);
  70                 if (n == -1 && errno != EINTR)
  71                         cu_err(1, "read");
  72                 if (n != 1 || input_stop)
  73                         break;
  74                 if (c == '\n') {
  75                         out = s;
  76                         break;
  77                 }
  78                 if (!iscntrl((u_char)c))
  79                         *cp++ = c;
  80         }
  81         *cp = '\0';
  82
  83         set_termios();
  84
  85         sigaction(SIGINT, &oact, NULL);
  86
  87         return (out);
  88 }