Startup Checker

• Download source - 11.25 KB
• Download demo - 46.22 KB

Introduction

The following dynamic link library searches for a certain process that was specified by the user / calling application, that is currently running. Thus if you want to prevent another process of the same application from opening / starting more than once, this function will do just that. I hope this will be useful.

Using the Code

To use the dynamic link library, follow these steps:

• Link your program with the .lib file.
• Project -> Settings -> Link -> Object/library modules.
• In the text area, add the startupchecker.lib file and click ok.
• After adding the library file, add the "startupchecker" header file.

#include "startupchecker.h"

After adding the .lib and header file, you can call the function.

• Function Name: seekProgram
• Function Parameters: char* Name (Exact Name of process to search for)
• Return Type: Integer
• Return: pid if found, else zero

Code Snippet from startupchecker.dll

HANDLE h_pro;
HANDLE h_sna;
PROCESSENTRY32 pe_sen = {0};

int result;
int returnValue;
int counter = 0;

char* ProcessNames = Name;

h_sna = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
if (h_sna == INVALID_HANDLE_VALUE){
    returnValue = -2;
    return (returnValue);
}

pe_sen.dwSize = sizeof(PROCESSENTRY32);

try{
    if (Process32First(h_sna, &pe_sen))
    {
        do
        {
            h_pro = OpenProcess (PROCESS_ALL_ACCESS, FALSE, pe_sen.th32ProcessID);
            CloseHandle (h_pro);
            
            if (pe_sen.th32ProcessID != 0)
            {
                result = strcmp (pe_sen.szExeFile,ProcessNames);
                
                if(result > 0){
                    // Not Found
                    returnValue = 0;
                }
                else if (result < 0){
                    // Not Found
                    returnValue = 0;
                }
                else
                {
                    // Found Process
                    globalVariable = pe_sen.th32ProcessID;
                    counter++;
                }
            }
        } while (Process32Next(h_sna, &pe_sen));
    }
}
catch(...)
{
    returnValue = -1;
}
CloseHandle (h_sna);

if (counter != 0 || counter > 0)
    return (globalVariable);     // Found the process and returning pid
else
    return 0;                    // Nothing was found

Code Snippet - Calling Function

int rc = seekProgram("winamp.exe");

History

• 10^th April, 2007: Initial post

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)