Added example

README.md

@@ -5,6 +5,67 @@ BETaskHelper helps you run NSTask interactively. Specifically you can:
 - receive output of the task line-by-line
 - send strings such as passwords to the task 
 
+## Example
+
+This example uses the `openssl` command to encrypt a file.
+
+In the header file implement the `BETaskHelperDelegate` protocol:
+
+	#import "BETaskHelper.h"
+
+	@interface FileEncrypter : NSObject <BETaskHelperDelegate> {
+		BETaskHelper *taskHelper;
+	}
+
+	// Sets up and runs the find task (you can call the method anything you like)
+	-(void) run;
+
+	@end
+
+Note that we keep the task helper as an instance variable because the task runs asynchronously.
+
+In the implementation file use the `BETaskHelper` delegate methods to capture the output of the `openssl` command and send the password when requested:
+
+	#import "FileEncrypter.h"
+
+	@implementation FileEncrypter
+
+	-(void) run {
+		// Setup task
+		NSTask *task = [[[NSTask alloc] init] autorelease];   // BETaskHelper will retain it for us
+		[task setLaunchPath:@"/usr/bin/openssl"];
+		NSString *inputPath = [NSHomeDirectory() stringByAppendingPathComponent:@"Report.txt"];
+		NSString *outputPath = [NSHomeDirectory() stringByAppendingPathComponent:@"Report.enc"];
+		
+		[task setArguments:[NSArray arrayWithObjects:@"enc", @"-aes-256-cbc", @"-salt", @"-in", inputPath, @"-out", outputPath, nil]];
+		
+		// Hook up task with helper
+		taskHelper = [[BETaskHelper alloc] initWithDelegate:self forTask:task];
+		
+		// Launch task -- must happen via task helper!
+		[taskHelper launchTask];
+	}
+
+	#pragma mark BETaskHelper delegate methods
+
+	-(void) task:(NSTask *)task hasOutputAvailable:(NSString *)outputLine {
+		// Log all output
+		NSLog(@"%@", outputLine);
+
+		// Send password if requested (will be called twice for verification)
+		if ([outputLine rangeOfString:@" password:"].location != NSNotFound) {
+			// Most commands require newline character to signal end of input
+			[taskHelper sendInput:@"YouWillNeverGuess\n"];
+		}
+	}
+
+	-(void) task:(NSTask *)task hasCompletedWithStatus:(int) status {
+		NSString *message = (status == 0) ? @"Success!" : @"Failed!";
+		NSLog(@"%@", message);
+	}
+
+	@end
+
 ## License
 
 Copyright (c) 2007, Incredible Bee Ltd. All rights reserved.