readline/examples/manexamp.c

   1 /* manexamp.c -- The examples which appear in the documentation are here. */
   2
   3 /* Copyright (C) 1987-2009 Free Software Foundation, Inc.
   4
   5    This file is part of the GNU Readline Library (Readline), a library for
   6    reading lines of text with interactive input and history editing.
   7
   8    Readline is free software: you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation, either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    Readline is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with Readline.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include <stdio.h>
  23 #include <readline/readline.h>
  24
  25 /* **************************************************************** */
  26 /*                                                                  */
  27 /*                      How to Emulate gets ()                      */
  28 /*                                                                  */
  29 /* **************************************************************** */
  30
  31 /* A static variable for holding the line. */
  32 static char *line_read = (char *)NULL;
  33
  34 /* Read a string, and return a pointer to it.  Returns NULL on EOF. */
  35 char *
  36 rl_gets ()
  37 {
  38   /* If the buffer has already been allocated, return the memory
  39      to the free pool. */
  40   if (line_read)
  41     {
  42       free (line_read);
  43       line_read = (char *)NULL;
  44     }
  45
  46   /* Get a line from the user. */
  47   line_read = readline ("");
  48
  49   /* If the line has any text in it, save it on the history. */
  50   if (line_read && *line_read)
  51     add_history (line_read);
  52
  53   return (line_read);
  54 }
  55
  56 /* **************************************************************** */
  57 /*                                                                  */
  58 /*        Writing a Function to be Called by Readline.              */
  59 /*                                                                  */
  60 /* **************************************************************** */
  61
  62 /* Invert the case of the COUNT following characters. */
  63 invert_case_line (count, key)
  64      int count, key;
  65 {
  66   register int start, end;
  67
  68   start = rl_point;
  69
  70   if (count < 0)
  71     {
  72       direction = -1;
  73       count = -count;
  74     }
  75   else
  76     direction = 1;
  77
  78   /* Find the end of the range to modify. */
  79   end = start + (count * direction);
  80
  81   /* Force it to be within range. */
  82   if (end > rl_end)
  83     end = rl_end;
  84   else if (end < 0)
  85     end = -1;
  86
  87   if (start > end)
  88     {
  89       int temp = start;
  90       start = end;
  91       end = temp;
  92     }
  93
  94   if (start == end)
  95     return;
  96
  97   /* Tell readline that we are modifying the line, so save the undo
  98      information. */
  99   rl_modifying (start, end);
 100
 101   for (; start != end; start += direction)
 102     {
 103       if (_rl_uppercase_p (rl_line_buffer[start]))
 104         rl_line_buffer[start] = _rl_to_lower (rl_line_buffer[start]);
 105       else if (_rl_lowercase_p (rl_line_buffer[start]))
 106         rl_line_buffer[start] = _rl_to_upper (rl_line_buffer[start]);
 107     }
 108
 109   /* Move point to on top of the last character changed. */
 110   rl_point = end - direction;
 111 }