From 95ae145cd11e1721e3f0d0a4fb7ff136d4191aed Mon Sep 17 00:00:00 2001
From: Jeremiah Orians <jeremiah@pdp10.guru>
Date: Mon, 18 Jul 2016 18:30:03 -0400
Subject: [PATCH] Added Minimal TTY library required for proper user interface
 approximation and fixed bugs in SET

---
 SET.c | 44 +++++++++++++++++++++++++++---------
 tty.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 105 insertions(+), 11 deletions(-)
 create mode 100644 tty.c

diff --git a/SET.c b/SET.c
index bfab39c..25015eb 100644
--- a/SET.c
+++ b/SET.c
@@ -13,6 +13,7 @@
 
 bool Reached_EOF;
 char temp[max_string + 1];
+char tty_getchar();
 
 struct Line
 {
@@ -21,6 +22,16 @@ struct Line
 	struct Line* prev;
 };
 
+int get_linenum(struct Line* p)
+{
+	if(NULL == p->prev)
+	{
+		return 0;
+	}
+
+	return get_linenum(p->prev) + 1;
+}
+
 struct Line* newLine()
 {
 	struct Line* p;
@@ -32,6 +43,7 @@ struct Line* newLine()
 		exit (EXIT_FAILURE);
 	}
 
+	p->Text[0] = '\n';
 	return p;
 }
 
@@ -128,10 +140,13 @@ struct Line* RemoveLine(struct Line* p)
 	if(NULL != p->prev)
 	{
 		p->prev->next = p->next;
-		return p->prev;
 	}
 
-	return p->next;
+	if(NULL != p->next)
+	{
+		return p->next;
+	}
+	return p->prev;
 }
 
 struct Line* InsertLine(struct Line* head)
@@ -176,10 +191,9 @@ struct Line* AppendLine(struct Line* head)
 	return head;
 }
 
-void Editor_loop(struct Line* head, FILE* source_file)
+void Editor_loop(struct Line* head, char* file_name)
 {
-	Readline(stdin);
-	switch(temp[0])
+	switch(tty_getchar())
 	{
 		case 'a':
 		{
@@ -190,7 +204,7 @@ void Editor_loop(struct Line* head, FILE* source_file)
 		{
 			if(NULL != head->prev)
 			{
-				Editor_loop(head->prev, source_file);
+				Editor_loop(head->prev, file_name);
 			}
 			break;
 		}
@@ -209,7 +223,7 @@ void Editor_loop(struct Line* head, FILE* source_file)
 		{
 			if(NULL != head->next)
 			{
-				Editor_loop(head->next, source_file);
+				Editor_loop(head->next, file_name);
 			}
 			break;
 		}
@@ -220,6 +234,7 @@ void Editor_loop(struct Line* head, FILE* source_file)
 		}
 		case 'p':
 		{
+			printf("Showing contents of line %04x:\n", get_linenum(head));
 			fputs(head->Text, stdout);
 			break;
 		}
@@ -229,8 +244,10 @@ void Editor_loop(struct Line* head, FILE* source_file)
 		}
 		case 'w':
 		{
-			rewind(source_file);
+			FILE* source_file;
+			source_file = fopen(file_name, "w");
 			WriteOut(GetHead(head), source_file);
+			fclose(source_file);
 			break;
 		}
 		case '?':
@@ -240,7 +257,7 @@ void Editor_loop(struct Line* head, FILE* source_file)
 		}
 	}
 
-	Editor_loop(head,source_file);
+	Editor_loop(head, file_name);
 }
 
 /* Standard C main program */
@@ -254,7 +271,10 @@ int main(int argc, char **argv)
 	}
 
 	FILE* source_file;
-	source_file = fopen(argv[1], "rw+");
+	char file_name[256] = {0};
+
+	strncpy(file_name, argv[1], 255);
+	source_file = fopen(file_name, "rw+");
 
 	Reached_EOF = false;
 	struct Line* head = NULL;
@@ -267,7 +287,9 @@ int main(int argc, char **argv)
 		head = addLine(head, p);
 	}
 
-	Editor_loop(head, source_file);
+	fclose(source_file);
+
+	Editor_loop(head, file_name);
 
 	return EXIT_SUCCESS;
 }
diff --git a/tty.c b/tty.c
new file mode 100644
index 0000000..6166e12
--- /dev/null
+++ b/tty.c
@@ -0,0 +1,72 @@
+#include <stdlib.h>
+#include <termios.h>
+#include <unistd.h>
+
+/****************************************************
+ * To make effective use of this library function:  *
+ * add prototypes for the bellow functions that you *
+ * wish to use. Please note that they contain bugs  *
+ ****************************************************/
+
+
+/* In order to restore at exit.*/
+static struct termios orig_termios;
+
+/* Raw mode: 1960 magic shit. */
+void enableRawMode()
+{
+	struct termios raw;
+
+	if(!isatty(STDIN_FILENO))
+	{
+		exit(EXIT_FAILURE);
+	}
+
+	if(tcgetattr(STDIN_FILENO, &orig_termios) == -1)
+	{
+		exit(EXIT_FAILURE);
+	}
+
+	raw = orig_termios;	 /* modify the original mode */
+	/* input modes: no break, no CR to NL, no parity check, no strip char,
+	 * no start/stop output control. */
+	raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
+	/* output modes - disable post processing */
+	raw.c_oflag &= ~(OPOST);
+	/* control modes - set 8 bit chars */
+	raw.c_cflag |= (CS8);
+	/* local modes - choing off, canonical off, no extended functions,
+	 * no signal chars (^Z,^C) */
+	raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
+	/* control chars - set return condition: min number of bytes and timer. */
+	raw.c_cc[VMIN] = 0; /* Return each byte, or zero for timeout. */
+	raw.c_cc[VTIME] = 1; /* 100 ms timeout (unit is tens of second). */
+
+	/* put terminal in raw mode after flushing */
+	if(tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw) < 0)
+	{
+		exit(EXIT_FAILURE);
+	}
+
+	return;
+}
+
+void disableRawMode()
+{
+	tcsetattr(STDIN_FILENO, TCSAFLUSH, &orig_termios);
+}
+
+char tty_getchar()
+{
+	int nread;
+	char c;
+
+	enableRawMode();
+	do
+	{
+		nread = read(STDIN_FILENO, &c, 1);
+	} while(nread  == 0);
+	disableRawMode();
+
+	return c;
+}