Add readline cmdline-editing extension
Patch by JinHua Luo, 01 Sep 2005
diff --git a/common/main.c b/common/main.c
index 758ef8d..ed4cb7b 100644
--- a/common/main.c
+++ b/common/main.c
@@ -2,6 +2,10 @@
  * (C) Copyright 2000
  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
  *
+ * Add to readline cmdline-editing by
+ * (C) Copyright 2005
+ * JinHua Luo, GuangDong Linux Center, <luo.jinhua@gd-linux.com>
+ *
  * See file CREDITS for list of people who contributed to this
  * project.
  *
@@ -516,6 +520,404 @@
 }
 #endif
 
+#ifdef CONFIG_CMDLINE_EDITING
+
+/*
+ * cmdline-editing related codes from vivi.
+ * Author: Janghoon Lyu <nandy@mizi.com>
+ */
+
+#if 1	/* avoid redundand code -- wd */
+#define putnstr(str,n)	do {			\
+		printf ("%.*s", n, str);	\
+	} while (0)
+#else
+void putnstr(const char *str, size_t n)
+{
+	if (str == NULL)
+		return;
+
+	while (n && *str != '\0') {
+		putc(*str);
+		str++;
+		n--;
+	}
+}
+#endif
+
+#define CTL_CH(c)		((c) - 'a' + 1)
+
+#define MAX_CMDBUF_SIZE		256
+
+#define CTL_BACKSPACE		('\b')
+#define DEL			((char)255)
+#define DEL7			((char)127)
+#define CREAD_HIST_CHAR		('!')
+
+#define getcmd_putch(ch)	putc(ch)
+#define getcmd_getch()		getc()
+#define getcmd_cbeep()		getcmd_putch('\a')
+
+#define HIST_MAX		20
+#define HIST_SIZE		MAX_CMDBUF_SIZE
+
+static int hist_max = 0;
+static int hist_add_idx = 0;
+static int hist_cur = -1;
+unsigned hist_num = 0;
+
+char* hist_list[HIST_MAX];
+char hist_lines[HIST_MAX][HIST_SIZE];
+
+#define add_idx_minus_one() ((hist_add_idx == 0) ? hist_max : hist_add_idx-1)
+
+static void hist_init(void)
+{
+	int i;
+
+	hist_max = 0;
+	hist_add_idx = 0;
+	hist_cur = -1;
+	hist_num = 0;
+
+	for (i = 0; i < HIST_MAX; i++) {
+		hist_list[i] = hist_lines[i];
+		hist_list[i][0] = '\0';
+	}
+}
+
+static void cread_add_to_hist(char *line)
+{
+	strcpy(hist_list[hist_add_idx], line);
+
+	if (++hist_add_idx >= HIST_MAX)
+		hist_add_idx = 0;
+
+	if (hist_add_idx > hist_max)
+		hist_max = hist_add_idx;
+
+	hist_num++;
+}
+
+static char* hist_prev(void)
+{
+	char *ret;
+	int old_cur;
+
+	if (hist_cur < 0)
+		return NULL;
+
+	old_cur = hist_cur;
+	if (--hist_cur < 0)
+		hist_cur = hist_max;
+
+	if (hist_cur == hist_add_idx) {
+		hist_cur = old_cur;
+		ret = NULL;
+	} else
+		ret = hist_list[hist_cur];
+
+	return (ret);
+}
+
+static char* hist_next(void)
+{
+	char *ret;
+
+	if (hist_cur < 0)
+		return NULL;
+
+	if (hist_cur == hist_add_idx)
+		return NULL;
+
+	if (++hist_cur > hist_max)
+		hist_cur = 0;
+
+	if (hist_cur == hist_add_idx) {
+		ret = "";
+	} else
+		ret = hist_list[hist_cur];
+
+	return (ret);
+}
+
+static void cread_print_hist_list(void)
+{
+	int i;
+	unsigned long n;
+
+	n = hist_num - hist_max;
+
+	i = hist_add_idx + 1;
+	while (1) {
+		if (i > hist_max)
+			i = 0;
+		if (i == hist_add_idx)
+			break;
+		printf("%s\n", hist_list[i]);
+		n++;
+		i++;
+	}
+}
+
+#define BEGINNING_OF_LINE() {			\
+	while (num) {				\
+		getcmd_putch(CTL_BACKSPACE);	\
+		num--;				\
+	}					\
+}
+
+#define ERASE_TO_EOL() {				\
+	if (num < eol_num) {				\
+		int tmp;				\
+		for (tmp = num; tmp < eol_num; tmp++)	\
+			getcmd_putch(' ');		\
+		while (tmp-- > num)			\
+			getcmd_putch(CTL_BACKSPACE);	\
+		eol_num = num;				\
+	}						\
+}
+
+#define REFRESH_TO_EOL() {			\
+	if (num < eol_num) {			\
+		wlen = eol_num - num;		\
+		putnstr(buf + num, wlen);	\
+		num = eol_num;			\
+	}					\
+}
+
+static void cread_add_char(char ichar, int insert, unsigned long *num,
+	       unsigned long *eol_num, char *buf, unsigned long len)
+{
+	unsigned long wlen;
+
+	/* room ??? */
+	if (insert || *num == *eol_num) {
+		if (*eol_num > len - 1) {
+			getcmd_cbeep();
+			return;
+		}
+		(*eol_num)++;
+	}
+
+	if (insert) {
+		wlen = *eol_num - *num;
+		if (wlen > 1) {
+			memmove(&buf[*num+1], &buf[*num], wlen-1);
+		}
+
+		buf[*num] = ichar;
+		putnstr(buf + *num, wlen);
+		(*num)++;
+		while (--wlen) {
+			getcmd_putch(CTL_BACKSPACE);
+		}
+	} else {
+		/* echo the character */
+		wlen = 1;
+		buf[*num] = ichar;
+		putnstr(buf + *num, wlen);
+		(*num)++;
+	}
+}
+
+static void cread_add_str(char *str, int strsize, int insert, unsigned long *num,
+	      unsigned long *eol_num, char *buf, unsigned long len)
+{
+	while (strsize--) {
+		cread_add_char(*str, insert, num, eol_num, buf, len);
+		str++;
+	}
+}
+
+static int cread_line(char *buf, unsigned int *len)
+{
+	unsigned long num = 0;
+	unsigned long eol_num = 0;
+	unsigned long rlen;
+	unsigned long wlen;
+	char ichar;
+	int insert = 1;
+	int esc_len = 0;
+	int rc = 0;
+	char esc_save[8];
+
+	while (1) {
+		rlen = 1;
+		ichar = getcmd_getch();
+
+		if ((ichar == '\n') || (ichar == '\r')) {
+			printf("\n");
+			break;
+		}
+
+		/*
+		 * handle standard linux xterm esc sequences for arrow key, etc.
+		 */
+		if (esc_len != 0) {
+			if (esc_len == 1) {
+				if (ichar == '[') {
+					esc_save[esc_len] = ichar;
+					esc_len = 2;
+				} else {
+					cread_add_str(esc_save, esc_len, insert,
+						      &num, &eol_num, buf, *len);
+					esc_len = 0;
+				}
+				continue;
+			}
+
+			switch (ichar) {
+
+			case 'D':	/* <- key */
+				ichar = CTL_CH('b');
+				esc_len = 0;
+				break;
+			case 'C':	/* -> key */
+				ichar = CTL_CH('f');
+				esc_len = 0;
+				break;	/* pass off to ^F handler */
+			case 'H':	/* Home key */
+				ichar = CTL_CH('a');
+				esc_len = 0;
+				break;	/* pass off to ^A handler */
+			case 'A':	/* up arrow */
+				ichar = CTL_CH('p');
+				esc_len = 0;
+				break;	/* pass off to ^P handler */
+			case 'B':	/* down arrow */
+				ichar = CTL_CH('n');
+				esc_len = 0;
+				break;	/* pass off to ^N handler */
+			default:
+				esc_save[esc_len++] = ichar;
+				cread_add_str(esc_save, esc_len, insert,
+					      &num, &eol_num, buf, *len);
+				esc_len = 0;
+				continue;
+			}
+		}
+
+		switch (ichar) {
+		case 0x1b:
+			if (esc_len == 0) {
+				esc_save[esc_len] = ichar;
+				esc_len = 1;
+			} else {
+				printf("impossible condition #876\n");
+				esc_len = 0;
+			}
+			break;
+
+		case CTL_CH('a'):
+			BEGINNING_OF_LINE();
+			break;
+		case CTL_CH('c'):	/* ^C - break */
+			*buf = '\0';	/* discard input */
+			return (-1);
+		case CTL_CH('f'):
+			if (num < eol_num) {
+				getcmd_putch(buf[num]);
+				num++;
+			}
+			break;
+		case CTL_CH('b'):
+			if (num) {
+				getcmd_putch(CTL_BACKSPACE);
+				num--;
+			}
+			break;
+		case CTL_CH('d'):
+			if (num < eol_num) {
+				wlen = eol_num - num - 1;
+				if (wlen) {
+					memmove(&buf[num], &buf[num+1], wlen);
+					putnstr(buf + num, wlen);
+				}
+
+				getcmd_putch(' ');
+				do {
+					getcmd_putch(CTL_BACKSPACE);
+				} while (wlen--);
+				eol_num--;
+			}
+			break;
+		case CTL_CH('k'):
+			ERASE_TO_EOL();
+			break;
+		case CTL_CH('e'):
+			REFRESH_TO_EOL();
+			break;
+		case CTL_CH('o'):
+			insert = !insert;
+			break;
+		case CTL_CH('x'):
+			BEGINNING_OF_LINE();
+			ERASE_TO_EOL();
+			break;
+		case DEL:
+		case DEL7:
+		case 8:
+			if (num) {
+				wlen = eol_num - num;
+				num--;
+				memmove(&buf[num], &buf[num+1], wlen);
+				getcmd_putch(CTL_BACKSPACE);
+				putnstr(buf + num, wlen);
+				getcmd_putch(' ');
+				do {
+					getcmd_putch(CTL_BACKSPACE);
+				} while (wlen--);
+				eol_num--;
+			}
+			break;
+		case CTL_CH('p'):
+		case CTL_CH('n'):
+		{
+			char * hline;
+
+			esc_len = 0;
+
+			if (ichar == CTL_CH('p'))
+				hline = hist_prev();
+			else
+				hline = hist_next();
+
+			if (!hline) {
+				getcmd_cbeep();
+				continue;
+			}
+
+			/* nuke the current line */
+			/* first, go home */
+			BEGINNING_OF_LINE();
+
+			/* erase to end of line */
+			ERASE_TO_EOL();
+
+			/* copy new line into place and display */
+			strcpy(buf, hline);
+			eol_num = strlen(buf);
+			REFRESH_TO_EOL();
+			continue;
+		}
+		default:
+			cread_add_char(ichar, insert, &num, &eol_num, buf, *len);
+			break;
+		}
+	}
+	*len = eol_num;
+	buf[eol_num] = '\0';	/* lose the newline */
+
+	if (buf[0] && buf[0] != CREAD_HIST_CHAR)
+		cread_add_to_hist(buf);
+	hist_cur = hist_add_idx;
+
+	return (rc);
+}
+
+#endif /* CONFIG_CMDLINE_EDITING */
+
 /****************************************************************************/
 
 /*
@@ -528,6 +930,20 @@
  */
 int readline (const char *const prompt)
 {
+#ifdef CONFIG_CMDLINE_EDITING
+	char *p = console_buffer;
+	unsigned int len=MAX_CMDBUF_SIZE;
+	static int initted = 0;
+
+	if (!initted) {
+		hist_init();
+		initted = 1;
+	}
+
+	printf("%s",prompt);
+
+	return cread_line(p, &len);
+#else
 	char   *p = console_buffer;
 	int	n = 0;				/* buffer index		*/
 	int	plen = 0;			/* prompt length	*/
@@ -623,6 +1039,7 @@
 			}
 		}
 	}
+#endif /* CONFIG_CMDLINE_EDITING */
 }
 
 /****************************************************************************/