contrib/libreadline/examples/manexamp.c

   1 /* manexamp.c -- The examples which appear in the documentation are here. */
   2
   3 #include <stdio.h>
   4 #include <readline/readline.h>
   5
   6
   7 /* **************************************************************** */
   8 /*                                                                  */
   9 *                       How to Emulate gets ()                      */
  10 /*                                                                  */
  11 /* **************************************************************** */
  12
  13 /* A static variable for holding the line. */
  14 static char *line_read = (char *)NULL;
  15
  16 /* Read a string, and return a pointer to it.  Returns NULL on EOF. */
  17 char *
  18 rl_gets ()
  19 {
  20   /* If the buffer has already been allocated, return the memory
  21      to the free pool. */
  22   if (line_read)
  23     {
  24       free (line_read);
  25       line_read = (char *)NULL;
  26     }
  27
  28   /* Get a line from the user. */
  29   line_read = readline ("");
  30
  31   /* If the line has any text in it, save it on the history. */
  32   if (line_read && *line_read)
  33     add_history (line_read);
  34
  35   return (line_read);
  36 }
  37
  38 /* **************************************************************** */
  39 /*                                                                  */
  40 /*        Writing a Function to be Called by Readline.              */
  41 /*                                                                  */
  42 /* **************************************************************** */
  43
  44 /* Invert the case of the COUNT following characters. */
  45 invert_case_line (count, key)
  46      int count, key;
  47 {
  48   register int start, end;
  49
  50   start = rl_point;
  51
  52   if (count < 0)
  53     {
  54       direction = -1;
  55       count = -count;
  56     }
  57   else
  58     direction = 1;
  59
  60   /* Find the end of the range to modify. */
  61   end = start + (count * direction);
  62
  63   /* Force it to be within range. */
  64   if (end > rl_end)
  65     end = rl_end;
  66   else if (end < 0)
  67     end = -1;
  68
  69   if (start > end)
  70     {
  71       int temp = start;
  72       start = end;
  73       end = temp;
  74     }
  75
  76   if (start == end)
  77     return;
  78
  79   /* Tell readline that we are modifying the line, so save the undo
  80      information. */
  81   rl_modifying (start, end);
  82
  83   for (; start != end; start += direction)
  84     {
  85       if (uppercase_p (rl_line_buffer[start]))
  86         rl_line_buffer[start] = to_lower (rl_line_buffer[start]);
  87       else if (lowercase_p (rl_line_buffer[start]))
  88         rl_line_buffer[start] = to_upper (rl_line_buffer[start]);
  89     }
  90
  91   /* Move point to on top of the last character changed. */
  92   rl_point = end - direction;
  93 }
  94