C# - Run a command on shutdown

[kbjradmin]

I am working on writing a program that will start automatically when the system boots, times how long the computer is running, and store that information in a file when the computer is shutdown. I know how to do all of this except the last part. Is there some way to make my program do something ( like store info in a file ) when the computer shutdown? I don't even know where to start on this, so if someone could explain the basic idea of how to do this, or point me to a tutorial or explaination about this, it would be greatly appreciated. Thanks in advance.

[saif7463]

I don't know C#, but I'm sure you could constantly store timedata in a textfile. When the computer is shutdown, the updating will cease, thus the textfile will contain the shutdown time.

[kbjradmin]

i guess that idea would work, but what kind of resources would that require? would the computer be able to do that and run other programs without slowing or lagging? i guess i'll start working on that and see how it works. thanks.

[misson]

If the app is running all the time, the application exits at system shutdown, so store the runtime just before the main application function ends. Depending on how you're handling system notifications, you can also either handle the SessionEnding event or WM_ENDSESSION message.

[kbjradmin]

misson, i'm still somewhat new to C#. i have a basic understanding of event handling, but don't know how to handle system notifications. i tried to see if i could figure out how to handle the SessionEnding event, but couldn't get it to work. this is what i have:

using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.ServiceProcess;
using System.Text;
using System.Windows;

namespace UseMonitor
{

    public class DataContainer
    {
        public static string filesource = @"C:\Documents and Settings\HP_Administrator\Desktop\UseMonitor\UseMonitor\bin\Debug\";
        public static string filename = filesource + "system_use.log";
    }

    public partial class UseMonitor : ServiceBase
    {

        public UseMonitor()
        {
            InitializeComponent();
        }

        protected override void OnStart(string[] args)
        {
            // check that the log file exists
            if (!File.Exists(DataContainer.filename))
                CreateLog(DataContainer.filename);
            // update the log file
            UpdateLog(DataContainer.filename, false);
        }

        protected override void OnStop()
        {
            UpdateLog(DataContainer.filename, "[S]");
        }

        public delegate void SessionEndingEventHandler(object sender, EventArgs e);

        public event SessionEndingEventHandler SessionEnding
        {
            add
            {
                UpdateLog(DataContainer.filename, true);
            }
            remove
            {
            }
        }

        /// <summary>
        /// Creates the log file if it does not already exist
        /// </summary>
        /// <param name="file"></param>
        public static void CreateLog(string filename)
        {
            StreamWriter log;
            log = File.CreateText(filename);
            log.WriteLine("This Log File Was Generated By UseMonitor.");
            log.WriteLine("Each entry in this log contains a boot date and time, shutdown/log off date and time, and a total time the session was active.");
            log.WriteLine("");
            log.WriteLine("Legend:");
            log.WriteLine("[S] - The UseMonitor service was stopped prematurly and does not have an acurate session end time.");
            log.WriteLine("");
            log.Close();
        }

        /// <summary>
        /// Update the log file
        /// Runs on start-up and session end
        /// </summary>
        /// <param name="stop">
        /// False if the function is running at start-up, True if running at session end
        /// </param>
        public static void UpdateLog(string filename, bool stop)
        {
            // get data needed
            string[] time = GetTime();
            int line = GetLogLength(filename);

            // append data to the file
            StreamWriter SW;
            SW = File.AppendText(filename);
            if (stop)
            {
                SW.WriteLine(" " + time[0] + " " + time[1] + time[2]);
            }
            else
            {
                SW.Write(time[0] + " " + time[1] + time[2]);
            }
            SW.Close();
        }

        /// <summary>
        /// Update the log file
        /// Runs on start-up and session end
        /// </summary>
        /// <param name="stop">
        /// False if the function is running at start-up, True if running at session end
        /// </param>
        /// <param name="comment">
        /// Any comments about the nature of the service stop
        /// </param>
        public static void UpdateLog(string filename, string comment)
        {
            // get data needed
            string[] time = GetTime();
            int line = GetLogLength(filename);

            // append data to the file
            StreamWriter SW;
            SW = File.AppendText(filename);
            SW.WriteLine(" " + time[0] + " " + time[1] + time[2] + " " + comment);
            SW.Close();
        }

        /// <summary>
        /// Counts the number of line in a file
        /// Note: Not used in the recent version
        /// </summary>
        /// <param name="filename"></param>
        /// <returns>The number of lines in filename</returns>
        public static int GetLogLength(string filename)
        {
            int count = 0;
            using (var reader = File.OpenText(filename))
            {
                while (reader.ReadLine() != null)
                {
                    count++;
                }
            }
            return count;
        }

        /// <summary>
        /// Gets the current date and time and isolates the seperate parts in an array.
        /// </summary>
        /// <returns>The date and time in an array</returns>
        public static string[] GetTime()
        {
            return DateTime.Now.ToString().Split(new Char[] { ' ' });
        }

    }

}

am i even close, or am i just way off?

[descalzo]

I could probably write it for you in perl.

What you do in perl is register a SIGNAL handler, since the system sends the running program a signal when the system is shutting down. Do they have signal handlers in C#?

Then open the file and write the starting time.

Then call sleep() in a loop. Does C# have a sleep function?

When the terminate signal is sent to the program, it writes the current time, closes the file and exits.

[misson]

namespace UseMonitor {
[...]
    public partial class UseMonitor : ServiceBase {
[...]
        public delegate void SessionEndingEventHandler(object sender, EventArgs e);

        public event SessionEndingEventHandler SessionEnding {
            add {
                UpdateLog(DataContainer.filename, true);
            }
            remove {}
        }
[...]
    }
}

am i even close, or am i just way off?

Not way off, but not exactly close. What you've done is defined an event on your UseMonitor class, so it can fire its own SessionEnding events. Take a look at "How do I... Catch system level events in C#?" and the following example:

using Microsoft.Win32;
namespace UseMonitor {
[...]
    public partial class UseMonitor : ServiceBase {
        static UseMonitor () {
            // register event handler
            SystemEvents.SessionEnding += new SessionEndingEventHandler(OnSessionEnding);
        }

        // define event handler
        private static void OnSessionEnding(object sender, SessionEndingEventArgs e) {
            UpdateLog(DataContainer.filename, true);
        }
        [...]
    }
}

[kbjradmin]

thank you, misson, for a very thorough answer as usual.


Edit:
ok, i tried doing what you said, but i still can't get it to work. what am i doing wrong? here is what i have now:

using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.ServiceProcess;
using System.Text;
using System.Windows;
using Microsoft.Win32;

namespace UseMonitor
{

    /// <summary>
    /// Used to contain variables needed by multiple methods
    /// </summary>
    public class DataContainer
    {
        public static string filesource = @"C:\Documents and Settings\HP_Administrator\Desktop\UseMonitor\UseMonitor\bin\Debug\";
        public static string filename = filesource + "system_use.log";
        public static DateTime startTime;
        public static DateTime endTime;
    }

    public partial class UseMonitor : ServiceBase
    {

        public UseMonitor()
        {
            InitializeComponent();
        }

        /// <summary>
        /// Occurs on service start
        /// </summary>
        /// <param name="args"></param>
        protected override void OnStart(string[] args)
        {
            SystemEvents.SessionEnding += new SessionEndingEventHandler(OnSessionEnding);
            // check that the log file exists
            if (!File.Exists(DataContainer.filename))
                CreateLog(DataContainer.filename);
            // update the log file
            UpdateLog(DataContainer.filename, false);
        }

        /// <summary>
        /// Occurs on service stop
        /// </summary>
        protected override void OnStop()
        {
            UpdateLog(DataContainer.filename, "[S]");
        }

        /// <summary>
        /// Occurs on session end (shutdown / logoff)
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private static void OnSessionEnding(object sender, SessionEndingEventArgs e)
        {
            UpdateLog(DataContainer.filename, true);
        }

        /// <summary>
        /// Creates the log file if it does not already exist
        /// </summary>
        /// <param name="file"></param>
        public static void CreateLog(string filename)
        {
            StreamWriter log;
            log = File.CreateText(filename);
            log.WriteLine("This Log File Was Generated By UseMonitor.");
            log.WriteLine("Each entry in this log contains a boot date and time, shutdown/log off date and time, and a total time the session was active.");
            log.WriteLine("");
            log.WriteLine("Legend:");
            log.WriteLine("[S] - The UseMonitor service was stopped prematurly and does not have an acurate session end time.");
            log.WriteLine("");
            log.Close();
        }

        /// <summary>
        /// Update the log file
        /// Runs on start-up and session end
        /// </summary>
        /// <param name="stop">
        /// False if the function is running at start-up, True if running at session end
        /// </param>
        public static void UpdateLog(string filename, bool stop)
        {
            // get data needed
            string[] time = GetTime();
            int line = GetLogLength(filename);

            // append data to the file
            StreamWriter SW;
            SW = File.AppendText(filename);
            if (stop)
            {
                DataContainer.endTime = DateTime.Parse(time[0] + " " + time[1] + " " + time[2]);
                TimeSpan totalTime = DataContainer.endTime.Subtract(DataContainer.startTime);
                SW.WriteLine("     " + time[0] + " " + time[1] + time[2] + "     " + WriteTime(totalTime));
            }
            else
            {
                DataContainer.startTime = DateTime.Parse(time[0] + " " + time[1] + " " + time[2]);
                SW.Write(time[0] + " " + time[1] + time[2]);
            }
            SW.Close();
        }

        /// <summary>
        /// Update the log file
        /// Runs on start-up and session end
        /// </summary>
        /// <param name="stop">
        /// False if the function is running at start-up, True if running at session end
        /// </param>
        /// <param name="comment">
        /// Any comments about the nature of the service stop
        /// </param>
        public static void UpdateLog(string filename, string comment)
        {
            // get data needed
            string[] time = GetTime();
            int line = GetLogLength(filename);

            // append data to the file
            StreamWriter SW;
            SW = File.AppendText(filename);
            DataContainer.endTime = DateTime.Parse(time[0] + " " + time[1] + " " + time[2]);
            TimeSpan totalTime = DataContainer.endTime.Subtract(DataContainer.startTime);
            SW.WriteLine("     " + time[0] + " " + time[1] + time[2] +  "     " + WriteTime(totalTime) + "     " + comment);
            SW.Close();
        }

        /// <summary>
        /// Counts the number of line in a file
        /// Note: Not used in the recent version
        /// </summary>
        /// <param name="filename"></param>
        /// <returns>The number of lines in filename</returns>
        public static int GetLogLength(string filename)
        {
            int count = 0;
            using (var reader = File.OpenText(filename))
            {
                while (reader.ReadLine() != null)
                {
                    count++;
                }
            }
            return count;
        }

        /// <summary>
        /// Gets the current date and time and isolates the seperate parts in an array.
        /// </summary>
        /// <returns>The date and time in an array</returns>
        public static string[] GetTime()
        {
            return DateTime.Now.ToString().Split(new Char[] { ' ' });
        }

        /// <summary>
        /// Converts a TimeSpan into a string in the format d:hh:mm:ss
        /// </summary>
        /// <param name="time"></param>
        /// <returns></returns>
        public static string WriteTime(TimeSpan time)
        {
            return time.Days + ":" + time.Hours + ":" + time.Minutes + ":" + time.Seconds;
        }

    }

}

[kbjradmin]

ok, i've gone from one problem to three...
first, there is the problem i first posted about (see previous post for details).
second, i have a part of my program that is using the current username. when i handcode the username in, it works fine; but when i use Environment.UserName, it doesn't work, and i can't figure out why.
third, is there anyway to get a list of all of the users on the computer?

here is my current code:

using Microsoft.Win32;
using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Management;
using System.Security.AccessControl;
using System.ServiceProcess;
using System.Text;
using System.Windows;
using System.Windows.Forms;

namespace UseMonitor
{

    /// <summary>
    /// Used to contain variables needed by multiple methods
    /// </summary>
    public class DataContainer
    {
        public static string filesource = Environment.GetEnvironmentVariable("userprofile") + @"\Desktop\UseMonitor\UseMonitor\bin\Debug\";
        public static string filename = filesource + "system_use.log";
        public static DateTime startTime;
        public static DateTime endTime;
        public static string systemName = Environment.MachineName; // YOUR-4DACD0EA75
        public static string userName = Environment.UserName; // HP_Administrator
        public static string[] userList = { "HP_Administrator" };
    }

    public partial class UseMonitor : ServiceBase
    {

        public UseMonitor()
        {
            SystemEvents.SessionEnding += new SessionEndingEventHandler(OnSessionEnding);
            InitializeComponent();
        }

        protected override void OnStart(string[] args)
        {
            // check that the log file exists
            if (!File.Exists(DataContainer.filename))
                CreateLog();
            // update the log file
            UpdateLog(false);
        }

        protected override void OnStop()
        {
            UpdateLog("[S]");
            SystemEvents.SessionEnding -= new SessionEndingEventHandler(OnSessionEnding);
        }

        void OnSessionEnding(object sender, SessionEndingEventArgs e)
        {
            UpdateLog(true);
        }

        public static void CreateLog()
        {
            StreamWriter log;
            log = File.CreateText(DataContainer.filename);
            log.WriteLine("This Log File Was Generated By UseMonitor.");
            log.WriteLine("Each entry in this log contains a boot date and time, shutdown/log off date and time, and a total time the session was active.");
            log.WriteLine("");
            log.WriteLine("Legend:");
            log.WriteLine("[S] - The UseMonitor service was stopped prematurly and does not have an acurate session end time.");
            log.WriteLine(""); log.WriteLine("");
            log.WriteLine("======================================================");
            log.WriteLine(""); log.WriteLine("");
            log.Close();

            // lock the file for all users on the system
            foreach (string user in DataContainer.userList)
            {
                LockFile(DataContainer.filename, DataContainer.systemName + "\\" + user, true);
            }
        }

        public static void UpdateLog(bool stop)
        {
            // get data needed
            string[] time = GetTime();
            int line = GetLogLength(DataContainer.filename);

            // unlock the log file
            LockFile(DataContainer.filename, DataContainer.systemName + "\\" + DataContainer.userName, false);

            // append data to the file
            StreamWriter SW;
            SW = File.AppendText(DataContainer.filename);
            if (stop)
            {
                DataContainer.endTime = DateTime.Parse(time[0] + " " + time[1] + " " + time[2]);
                TimeSpan totalTime = DataContainer.endTime.Subtract(DataContainer.startTime);
                SW.WriteLine("     " + time[0] + " " + time[1] + time[2] + "     " + WriteTime(totalTime));
            }
            else
            {
                DataContainer.startTime = DateTime.Parse(time[0] + " " + time[1] + " " + time[2]);
                SW.Write(time[0] + " " + time[1] + time[2]);
            }
            SW.Close();

            // re-lock the log file
            LockFile(DataContainer.filename, DataContainer.systemName + "\\" + DataContainer.userName, true);
        }

        public static void UpdateLog(string comment)
        {
            // get data needed
            string[] time = GetTime();
            int line = GetLogLength(DataContainer.filename);

            // unlock the log file
            LockFile(DataContainer.filename, DataContainer.systemName + "\\" + DataContainer.userName, false);

            // append data to the file
            StreamWriter SW;
            SW = File.AppendText(DataContainer.filename);
            DataContainer.endTime = DateTime.Parse(time[0] + " " + time[1] + " " + time[2]);
            TimeSpan totalTime = DataContainer.endTime.Subtract(DataContainer.startTime);
            SW.WriteLine("     " + time[0] + " " + time[1] + time[2] +  "     " + WriteTime(totalTime) + "     " + comment);
            SW.Close();

            // re-lock the log file
            LockFile(DataContainer.filename, DataContainer.systemName + "\\" + DataContainer.userName, true);
        }

        public static int GetLogLength(string filename)
        {
            int count = 0;
            using (var reader = File.OpenText(filename))
            {
                while (reader.ReadLine() != null)
                {
                    count++;
                }
            }
            return count;
        }

        public static string[] GetTime()
        {
            return DateTime.Now.ToString().Split(new Char[] { ' ' });
        }

        public static string WriteTime(TimeSpan time)
        {
            return time.Days + ":" + time.Hours + ":" + time.Minutes + ":" + time.Seconds;
        }

        public static void AddFileSecurity(string fileName, string account, FileSystemRights rights, AccessControlType controlType)
        {

            // Get a FileSecurity object that represents the
            // current security settings.
            System.Security.AccessControl.FileSecurity fSecurity = File.GetAccessControl(fileName);

            // Add the FileSystemAccessRule to the security settings.
            fSecurity.AddAccessRule(new FileSystemAccessRule(account, rights, controlType));

            // Set the new access settings.
            File.SetAccessControl(fileName, fSecurity);

        }

        public static void RemoveFileSecurity(string fileName, string account, FileSystemRights rights, AccessControlType controlType)
        {

            // Get a FileSecurity object that represents the
            // current security settings.
            System.Security.AccessControl.FileSecurity fSecurity = File.GetAccessControl(fileName);

            // Add the FileSystemAccessRule to the security settings.
            fSecurity.RemoveAccessRule(new FileSystemAccessRule(account, rights, controlType));

            // Set the new access settings.
            File.SetAccessControl(fileName, fSecurity);

        }

        public static void LockFile(string filename, string account, bool lockfile)
        {
            if (lockfile)
            {
                AddFileSecurity(filename, account, FileSystemRights.Write, AccessControlType.Deny);
                AddFileSecurity(filename, account, FileSystemRights.Delete, AccessControlType.Deny);
                AddFileSecurity(filename, account, FileSystemRights.ChangePermissions, AccessControlType.Deny);
            }
            else
            {
                RemoveFileSecurity(filename, account, FileSystemRights.Write, AccessControlType.Deny);
                RemoveFileSecurity(filename, account, FileSystemRights.Delete, AccessControlType.Deny);
                RemoveFileSecurity(filename, account, FileSystemRights.ChangePermissions, AccessControlType.Deny);
            }
        }

    }

}

thanks in advance for any help.

[misson]

ok, i've gone from one problem to three...
first, there is the problem i first posted about (see previous post for details).

From the MSDN documentation for SessionEnding

This event is only raised if the message pump is running. In a Windows service, unless a hidden form is used or the message pump has been started manually, this event will not be raised. For a code example that shows how to handle system events by using a hidden form in a Windows service, see the SystemEvents class.

second, i have a part of my program that is using the current username. when i handcode the username in, it works fine; but when i use Environment.UserName, it doesn't work, and i can't figure out why.

Is the handcoded user name the same as Environment.UserName? One potential problem is you're adding a deny permission for FileSystemRights.ChangePermissions, which means non-admins can't then remove all the deny permissions.

Note that you don't need separate calls to AddFileSecurity/RemoveFileSecurity because you can combine permissions by or-ing them:

 AddFileSecurity(filename, account, 
                        FileSystemRights.Write | FileSystemRights.Delete | FileSystemRights.ChangePermissions, 
                        AccessControlType.Deny);

Also, having separate LockFile and UnlockFile methods rather than a single LockFile method is cleaner.

If you're using file permissions for exclusive access, the better way is to use file locks, via the FileShare argument to the FileStream constructor.

        public static void UpdateLog(string comment) {
            // get data needed
            string[] time = GetTime();
            int line = GetLogLength(DataContainer.filename);

            // append data to the file
            FileStream fs = new FileStream(DataContainer.filename, FileMode.Append, FileAccess.Write, FileShare.Read);
            StreamWriter log = new StreamWriter(fs);
            ...
            log.Close(); // also closes fs
        }

FileShare.Read allows other processes to open the log file with read access but not write access. Use FileShare.None for exclusive access.

third, is there anyway to get a list of all of the users on the computer?

Should be moot at this point, but here's one way.