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Overview

This page documents utility functions for working with processes, including checking if a process is alive, getting architecture information, and managing command line arguments.

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LM_IsProcessAlive

Checks if a given process is alive based on its PID and start time.

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Function Signature

LM_API lm_bool_t LM_CALL
LM_IsProcessAlive(const lm_process_t *process);

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Parameters

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process
const lm_process_t *
required
The process that will be checked. Both the PID and start time are used to verify the process is the same instance.

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Return Value

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return
lm_bool_t
Returns LM_TRUE if the process specified by the input lm_process_t is alive, or LM_FALSE otherwise.

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Example

lm_process_t target;

if (LM_FindProcess("game.exe", &target)) {
    printf("Found process\n");
    
    // Do some work...
    
    // Check if still alive
    if (LM_IsProcessAlive(&target)) {
        printf("Process is still running\n");
    } else {
        printf("Process has terminated\n");
    }
}

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Notes

  • This function checks both PID and start time to avoid false positives from PID reuse
  • More reliable than just checking if a PID exists
  • Useful for monitoring target processes in injectors or debuggers

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LM_GetBits

Returns the size of a pointer in bits, which corresponds to the current process’s bits (32 bits or 64 bits).

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Function Signature

LM_API lm_size_t LM_CALL
LM_GetBits();

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Parameters

This function takes no parameters.

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Return Value

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return
lm_size_t
Returns the size of a pointer in bits. Typically 32 or 64.

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Example

lm_size_t bits = LM_GetBits();
printf("Current process is %zu-bit\n", bits);

if (bits == 64) {
    printf("Running in 64-bit mode\n");
} else {
    printf("Running in 32-bit mode\n");
}

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Notes

  • Returns the architecture of the current process, not the system
  • Useful for determining pointer sizes and offsets
  • A 32-bit process on a 64-bit system will return 32

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LM_GetSystemBits

Returns the system architecture bits (32 bits or 64 bits).

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Function Signature

LM_API lm_size_t LM_CALL
LM_GetSystemBits();

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Parameters

This function takes no parameters.

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Return Value

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return
lm_size_t
Returns the system bits. Typically 32 or 64.

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Example

lm_size_t system_bits = LM_GetSystemBits();
lm_size_t process_bits = LM_GetBits();

printf("System: %zu-bit\n", system_bits);
printf("Process: %zu-bit\n", process_bits);

if (system_bits == 64 && process_bits == 32) {
    printf("Running 32-bit process on 64-bit system (WoW64)\n");
}

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Notes

  • Returns the architecture of the operating system, not the current process
  • On Windows, useful for detecting WoW64 (32-bit process on 64-bit Windows)
  • The system bits are always >= the process bits

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LM_GetCommandLine

Retrieves the command line arguments of a process.

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Function Signature

LM_API lm_char_t ** LM_CALL
LM_GetCommandLine(lm_process_t *process);

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Parameters

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process
lm_process_t *
required
The process to retrieve the command line from.

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Return Value

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return
lm_char_t **
Returns an allocated NULL-terminated array of strings containing the command line arguments, or NULL if it fails. The returned array must be freed with LM_FreeCommandLine.

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Example

lm_process_t target;

if (LM_FindProcess("game.exe", &target)) {
    lm_char_t **cmdline = LM_GetCommandLine(&target);
    
    if (cmdline) {
        printf("Command line arguments:\n");
        for (int i = 0; cmdline[i] != NULL; i++) {
            printf("  [%d]: %s\n", i, cmdline[i]);
        }
        
        LM_FreeCommandLine(cmdline);
    } else {
        printf("Failed to get command line\n");
    }
}

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Notes

  • WARNING: On Windows, this function requires reading process memory
  • Always free the returned buffer with LM_FreeCommandLine
  • May require elevated privileges on some systems
  • Returns NULL on failure

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LM_FreeCommandLine

Frees a command line buffer obtained from LM_GetCommandLine.

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Function Signature

LM_API lm_void_t LM_CALL
LM_FreeCommandLine(lm_char_t **cmdline);

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Parameters

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cmdline
lm_char_t **
required
The allocated command line buffer to free.

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Return Value

This function does not return a value.

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Example

lm_char_t **cmdline = LM_GetCommandLine(&process);
if (cmdline) {
    // Use the command line...
    
    // Free when done
    LM_FreeCommandLine(cmdline);
}

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Notes

  • Always call this function to free memory allocated by LM_GetCommandLine
  • Safe to call with NULL pointer (no-op)
  • Failure to free will cause memory leaks

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Complete Example

Here’s a complete example demonstrating all utility functions: 
#include <libmem/libmem.h>
#include <stdio.h>

int main()
{
    // Get system and process architecture info
    lm_size_t system_bits = LM_GetSystemBits();
    lm_size_t process_bits = LM_GetBits();
    
    printf("System: %zu-bit\n", system_bits);
    printf("Current process: %zu-bit\n", process_bits);
    
    // Find a target process
    lm_process_t target;
    if (!LM_FindProcess("game.exe", &target)) {
        printf("Process not found\n");
        return 1;
    }
    
    printf("\nFound process: %s\n", target.name);
    printf("  PID: %d\n", target.pid);
    printf("  Bits: %zu\n", target.bits);
    
    // Check if architecture matches
    if (target.bits != process_bits) {
        printf("  WARNING: Architecture mismatch!\n");
    }
    
    // Get command line arguments
    lm_char_t **cmdline = LM_GetCommandLine(&target);
    if (cmdline) {
        printf("\nCommand line arguments:\n");
        for (int i = 0; cmdline[i] != NULL; i++) {
            printf("  [%d]: %s\n", i, cmdline[i]);
        }
        LM_FreeCommandLine(cmdline);
    }
    
    // Monitor process
    printf("\nMonitoring process...\n");
    int checks = 0;
    while (checks < 10 && LM_IsProcessAlive(&target)) {
        printf("Process still alive (check %d/10)\n", ++checks);
        sleep(1);
    }
    
    if (!LM_IsProcessAlive(&target)) {
        printf("Process has terminated\n");
    }
    
    return 0;
}

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See Also

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