proctl

List available licenses

$ proctl [-ll|-list-licenses]

$ proctl [-lL|-list-languages]

$ proctl [-pl|-pick-license]

$ proctl [-pL|-pick-language]

$ proctl [-r|-remove-license]

$ proctl [-t|-new-template]

$ proctl [-R|-delete-license] [@license_name1 @license_name2 ...]

$ proctl [-h|-help]

proctl [-s] [-f] [-w file] pid command [args...]

pid
    The process ID of the target process.

-s
    Stop the process before executing the command (if supported by the specific implementation).

-f
    Fork a new process before executing the command (if supported).

-w file
    Write the core image to the given file (if supported).

command
    The command to execute within the context of the target process. Commonly used commands might include reading memory, writing memory, setting breakpoints, or examining registers. Different implementations have different set of commands, which must be consulted in the documentation.

args...
    Arguments to the 'command'.

The proctl command is a versatile tool used in some Unix-like systems (though less common now) for controlling process execution and inspecting process memory.

Historically, it provided capabilities similar to those now found in more modern tools like ptrace, gdb, and other process debugging utilities. Its primary function was to allow a user (typically a debugger or system administrator) to examine and modify the state of a running process. This included features like reading and writing memory, setting breakpoints, single-stepping execution, and examining registers. It gave the possibility to attach to the target process and perform variety of actions.

While not a standard command across all Linux distributions today, understanding its purpose offers insight into the evolution of process control and debugging techniques. Modern systems largely rely on more sophisticated and standardized mechanisms. However, the basic principles remain the same: a program needs a mechanism to interact with another process for debugging, monitoring, or control purposes.

proctl is not a standard Linux command and is not universally available. Its availability and functionality depend heavily on the specific Unix-like operating system and its version. The exact commands it supports and their syntax vary significantly. Modern systems typically use ptrace and related tools for process control.

Using proctl requires appropriate privileges, typically root or membership in a specific group. Improper use can lead to system instability or security breaches, as it allows arbitrary modification of running processes. Because of this and the ability to potentially disrupt or steal information from processes, strict access control is vital.

For process control and debugging on modern Linux systems, tools like gdb, ptrace (used by debuggers and system monitoring tools), and tracing utilities like strace and ltrace are preferred. These tools offer more comprehensive features, better standardization, and often improved security compared to older tools like proctl.

The proctl command has its roots in early Unix systems as a tool for debugging and process control. It offered a means to interact with running processes at a low level, enabling tasks such as examining memory, setting breakpoints, and single-stepping execution. Over time, its functionality was often superseded by more powerful and standardized tools like ptrace and debuggers like gdb. As a result, proctl's usage declined, and it is now less common in modern Linux distributions.

ptrace(2), gdb(1), strace(1), kill(1)