Erik modified rc directly to add a history system.

On Jan 23, 2009, at 5:50 AM, Francisco J Ballesteros wrote:

> Russ posted two script called " and "" time ago on this list,
> IIRC.
>
>
> On Fri, Jan 23, 2009 at 11:03 AM, pavel.klinkovsky@gmail.com
> <pavel.klinkovsky@gmail.com> wrote:
>> Hi all,
>>
>> In Plan9 I missed the simple way to repeat previous (or previous of
>> previous etc.) command in the terminal.
>> I prepared a very small (an stupid) program to allow that.
>>
>> Compile the following source code and run it in that way:
>> 8.out | rc -i
>>
>> You can insert the commands, and if you want to walk through the
>> "history", just press CTRL+K (backward) or CTRL+L (foreward).
>>
>> That is all, folks. ;-)
>>
>> Pavel
>>
>>
>> #include <u.h>
>> #include <libc.h>
>>
>> enum
>> {
>>       KCtrlD = 0x04,
>>       KCtrlK = 0x0B,
>>       KCtrlL = 0x0C,
>>       KDelete = 0x7F,
>>
>>       MaxLen = 128,
>>       MaxDepth = 10
>> };
>>
>> struct Line
>> {
>>       int len;
>>       char buf[MaxLen];
>> };
>> typedef struct Line Line;
>>
>> void
>> main(void)
>> {
>>       // Console control file descriptor
>>       int cfd;
>>       // End flag
>>       int end = 0;
>>       // Actual read character
>>       char c;
>>       // Array of BackSpaces
>>       char bs[MaxLen];
>>       // Array of Lines
>>       Line line[MaxDepth];
>>       // Index of actual line
>>       int act = 0;
>>       // Index of stored line
>>       int stored = 0;
>>
>>       memset(bs, '\b', sizeof(bs));
>>       memset(line, 0, sizeof(line));
>>
>>       cfd = open("/dev/consctl", OWRITE);
>>       if (cfd < 0)
>>               sysfatal("%r");
>>       write(cfd, "rawon", 5);
>>
>>       while (!end) {
>>               if (read(0, &c, sizeof(c)) < 0)
>>                       sysfatal("%r");
>>
>>               switch (c) {
>>               case KCtrlD:
>>               case KDelete:
>>                       end++;
>>                       break;
>>
>>               case '\b':
>>                       if (line[act].len > 0) {
>>                               line[act].len--;
>>                               write(2, &c, sizeof(c));
>>                       }
>>                       break;
>>
>>               case '\n':
>>                       if (line[act].len > 0)
>>                               write(1, line[act].buf, line[act].len);
>>                       write(1, &c, sizeof(c));
>>                       write(2, &c, sizeof(c));
>>                       act = stored = (act + 1) % MaxDepth;
>>                       line[act].len = 0;
>>                       break;
>>
>>               case KCtrlK:
>>                       write(2, bs, line[act].len);
>>                       stored = (stored + MaxDepth - 1) % MaxDepth;
>>                       line[act] = line[stored];
>>                       write(2, line[act].buf, line[act].len);
>>                       break;
>>
>>               case KCtrlL:
>>                       write(2, bs, line[act].len);
>>                       stored = (stored + 1) % MaxDepth;
>>                       line[act] = line[stored];
>>                       write(2, line[act].buf, line[act].len);
>>                       break;
>>
>>               case -0x11:
>>                       read(0, &c, sizeof(c));
>>                       read(0, &c, sizeof(c));
>>                       break;
>>
>>               default:
>>                       if (line[act].len < MaxLen) {
>>                               line[act].buf[line[act].len++] = c;
>>                               write(2, &c, sizeof(c));
>>                       }
>>                       break;
>>               }
>>       }
>>
>>       close(cfd);
>>
>>       exits(nil);
>> }
>>
>>
>