1 files changed, 139 insertions, 0 deletions
diff --git a/src/user/lib/std/readline.c b/src/user/lib/std/readline.c
new file mode 100644
index 0000000..a3beefa
--- /dev/null
+++ b/src/user/lib/std/readline.c
@@ -0,0 +1,139 @@
+#include <readline.h>
+#include <stdlib.h>
+
+char* freadln(FILE f) {
+	fprint(f, "\x1b[e");	// enable keyboard echo
+	int i;
+
+	char *p = (char*)malloc(256);
+	char *b = p;
+
+	while (1) {
+		int l = read(f, 0, 255, b);
+		if (l < 0) {
+			free(b);
+			return 0;
+		}
+
+		for (i = 0; i < l; i++) {
+			if (b[i] == '\n') {
+				b[i+1] = 0;
+				return p;
+			} else if (b[i] == 27) {		// ignore escape sequences
+				b[i] = 0;
+				l = i;
+			}
+		}
+
+		int d = b - p + l;
+
+		char* newp = (char*)malloc(d + 256);
+		memcpy(newp, p, d);
+		free(p);
+		p = newp;
+		b = p + d;
+	}
+}
+
+
+// ** READLINE
+
+char *readline(FILE f, readline_history *h) {
+	int i;
+	fprint(f, "\x1b[h");	// disable keyboard echo
+
+	if (h->str == 0) {
+		h->str = (char**)malloc(h->max * sizeof(char*));
+		for (i = 0; i < h->max; i++) h->str[i] = 0;
+		h->n = 0;
+	}
+
+	int lid;
+	if (h->n < h->max) {
+		lid = h->n++;
+	} else {
+		free(h->str[0]);
+		int i;
+		for (i = 0; i < h->max - 1; i++) {
+			h->str[i] = h->str[i+1];
+		}
+		lid = h->max - 1;
+		h->str[lid] = 0;
+	}
+
+	if (h->str[lid] == 0) h->str[lid] = (char*)malloc(256);
+
+	char *str = h->str[lid];
+	str[0] = 0;
+	char *cur = str;	// position in string
+	int len = 0;		// string length
+
+	while (1) {
+		int finished = 0;
+
+		int te = cur - str;
+
+		char buf[16];
+		int l = read(f, 0, 16, buf);
+		if (l < 0) return 0;
+
+		if (buf[0] == 27) {
+			if (buf[1] == '[') {
+				if (buf[2] == 'A') {			// up
+					if (lid > 0) {
+						lid--;
+						str = h->str[lid];
+						len = strlen(str);
+						cur = str + len;
+					}
+				} else if (buf[2] == 'B') {		// down
+					if (lid < h->n - 1) {
+						lid++;
+						str = h->str[lid];
+						len = strlen(str);
+						cur = str + len;
+					}
+				} else if (buf[2] == 'C') {		// forward (right)
+					if (cur < str + len) cur++;
+				} else if (buf[2] == 'D') {		// back (left)
+					if (cur > str) cur--;
+				}
+			} else {
+				// ALT sequence - ignore
+			}
+		} else if (buf[0] == '\n') {
+			finished = 1;
+			cur = str + len;
+		} else if (buf[0] == '\b') {
+			if (cur > str) {
+				cur--;
+				len--;
+				char* c;
+				for (c = cur; *c != 0; c++) c[0] = c[1];
+			}
+		} else if (buf[0] == '\t') {
+			// ignore tabs -- todo: tab completion???? haha
+		} else if (buf[0] >= ' ') {
+			if (l < 255) {
+				char* c;
+				for (c = cur + len; c >= cur; c--) c[1] = c[0];
+				cur[0] = buf[0];
+				cur++;
+				len++;
+			}
+		}
+
+		// ASSUMPTION : everything will fit on one line...
+		if (te > 0) fprintf(f, "\x1b[%iD", te);
+		fprintf(f, "\x1b[K%s", str);
+		te = len - (cur - str);
+		if (te > 0) fprintf(f, "\x1b[%iD", te);
+		
+		
+		if (finished) {
+			fprintf(f, "\n");
+			if (h->str[h->n-1][0] == 0) h->n--;
+			return str;
+		}
+	}
+}