From ed5e9f689fa28c6fe88be1f3076e6d9804ab3a01 Mon Sep 17 00:00:00 2001
From: Brian Barto <bartobrian@gmail.com>
Date: Sun, 1 May 2016 17:09:38 -0400
Subject: [PATCH] Support for the '-a' command line option to auto-start the
 decryption effect

	modified:   README.md
	modified:   src/main.c
	modified:   src/nms.c
	modified:   src/nms.h
---
 README.md  | 11 +++++++++++
 src/main.c | 21 +++++++++++++++++++--
 src/nms.c  | 11 ++++-------
 src/nms.h  |  3 ++-
 4 files changed, 36 insertions(+), 10 deletions(-)

diff --git a/README.md b/README.md
index 17dc70f..d1a14f2 100644
--- a/README.md
+++ b/README.md
@@ -62,6 +62,14 @@ Once the "encrypted" data is displayed, the program will pause until you press a
 decryption effect will start. After that is completed, it will again pause until
 you press a key, at which point the program will terminate.
 
+#### Command Line Options
+
+Use the `-a` option to set the auto_decrypt flag. This will automatically start the decryption effect,
+eliminating the need for the user to press a key to start it.
+```
+ls -l / | nms -a
+```
+
 Using the Module in Your Program
 ---------------------------------
 
@@ -120,6 +128,7 @@ typedef struct {
     int input_cursor_x;
     int input_cursor_y;
     bool show_cursor;
+    bool auto_decrypt;
 } NmsArgs;
 ```
 * `char *src`
@@ -133,6 +142,8 @@ Useful for displaying menus:
   * If your menu has a specific location that you'd like to place the cursor for user input, use these to set the x and y screen coordinates for the position.
 * `bool show_cursor`
   * Set to `true` if you want the cursor to be visible during the text decryption effect. It is set to `false` by default.
+* `bool auto_decrypt`
+  * Set to `true` to automatically start the decryption effect, eliminating the need for the user to press a key to start it.
 
 Assign values to the structure members as needed. Then simply pass a pointer to the structure to the
 nms_exec() function:
diff --git a/src/main.c b/src/main.c
index 60c23fd..3fae0be 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,13 +1,30 @@
 #include <stdio.h>
 #include <stdlib.h>
+#include <unistd.h>
+#include <ctype.h>
 #include "nms.h"
 
-int main(void) {
+int main(int argc, char *argv[]) {
+	int c, o, inSize = 0;
 	char *input = NULL;
 	NmsArgs args = INIT_NMSARGS;
 
+	// Processing command arguments
+	while ((o = getopt(argc, argv, "a")) != -1) {
+		switch (o) {
+			case 'a':
+                args.auto_decrypt = true;
+                break;
+			case '?':
+				if (isprint(optopt))
+					fprintf (stderr, "Unknown option '-%c'.\n", optopt);
+				else
+					fprintf (stderr, "Unknown option character '\\x%x'.\n", optopt);
+                return 1;
+        }
+    }
+
 	// Geting input
-	int c, inSize = 0;
 	while ((c = getchar()) != EOF) {
 		++inSize;
 		input = realloc(input, inSize + 1);
diff --git a/src/nms.c b/src/nms.c
index 39b80d3..4de277c 100644
--- a/src/nms.c
+++ b/src/nms.c
@@ -153,13 +153,10 @@ char nms_exec(NmsArgs *args) {
 	// Flush any input up to this point
 	flushinp();
 
-	// Reopen stdin for interactive input (keyboard), then require user
-	// to press a key to continue.
-	if (!isatty(STDIN_FILENO))
-		if (!freopen ("/dev/tty", "r", stdin))
-			sleep(1);
-		else
-			getch();
+	// If auto_decrypt flag is set, we sleep. Otherwise, reopen stdin for interactive
+	// input (keyboard), then require user to press a key to continue.
+	if (args->auto_decrypt == true || (!isatty(STDIN_FILENO) && !freopen ("/dev/tty", "r", stdin)))
+		sleep(1);
 	else
 		getch();
 
diff --git a/src/nms.h b/src/nms.h
index c7d63e2..e614aff 100644
--- a/src/nms.h
+++ b/src/nms.h
@@ -5,7 +5,7 @@
 #include <stdbool.h>
 
 // Default arguments for nms_exec()
-#define INIT_NMSARGS { NULL, NULL, -1, -1, false }
+#define INIT_NMSARGS { NULL, NULL, -1, -1, false, false }
 
 // Argument structure for nms_exec()
 typedef struct {
@@ -14,6 +14,7 @@ typedef struct {
 	int input_cursor_x;
 	int input_cursor_y;
 	bool show_cursor;
+	bool auto_decrypt;
 } NmsArgs;
 
 // Display the characters stored in the display queue