readline/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 do_gets ()
  19 {
  20   /* If the buffer has already been allocated, return the memory
  21      to the free pool. */
  22   if (line_read != (char *)NULL)
  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 /*                                                                  */
  41 /*        Writing a Function to be Called by Readline.              */
  42 /*                                                                  */
  43 /* **************************************************************** */
  44
  45 /* Invert the case of the COUNT following characters. */
  46 invert_case_line (count, key)
  47      int count, key;
  48 {
  49   register int start, end;
  50
  51   start = rl_point;
  52
  53   if (count < 0)
  54     {
  55       direction = -1;
  56       count = -count;
  57     }
  58   else
  59     direction = 1;
  60
  61   /* Find the end of the range to modify. */
  62   end = start + (count * direction);
  63
  64   /* Force it to be within range. */
  65   if (end > rl_end)
  66     end = rl_end;
  67   else if (end < 0)
  68     end = -1;
  69
  70   if (start > end)
  71     {
  72       int temp = start;
  73       start = end;
  74       end = temp;
  75     }
  76
  77   if (start == end)
  78     return;
  79
  80   /* Tell readline that we are modifying the line, so save the undo
  81      information. */
  82   rl_modifying (start, end);
  83
  84   for (; start != end; start += direction)
  85     {
  86       if (uppercase_p (rl_line_buffer[start]))
  87         rl_line_buffer[start] = to_lower (rl_line_buffer[start]);
  88       else if (lowercase_p (rl_line_buffer[start]))
  89         rl_line_buffer[start] = to_upper (rl_line_buffer[start]);
  90     }
  91
  92   /* Move point to on top of the last character changed. */
  93   rl_point = end - direction;
  94 }
  95
  96