OllyDbg vs Perl Debugger

OllyDbg is a free 32-bit assembler-level debugger for Microsoft Windows, intended for binary analysis when source code is unavailable. It traces registers and identifies procedures, loops, API calls, switches, tables, constants, and strings. The debugger can load DLLs, attach to running programs, and handle multithreaded applications. Breakpoint types include conditional, logging, memory, and hardware breakpoints; execution tracing can log arguments for known functions. Patches can be retained between sessions, written back to executable files, and used to update fixups. An open architecture supports third-party plugins, and the maker provides a Plugin Development Kit with documented samples. Listed requirements include Windows 95, 98, NT 4.0, 2000, or higher; Win32s is unsupported. Development is frozen, and the 64-bit version is incomplete. Registration is free and requested for permanent or commercial use. The maker says original versions 1.00–1.10 do not communicate with other computers except for remote files specified by the user.

Perl Debugger is an interactive debugger included with Perl, not a separate program. Running Perl with the `-d` flag loads the debugger and adds source information, allowing users to inspect code, set breakpoints, view stack backtraces, and change variable values. The program must compile correctly before debugging.

Debugger commands support stepping into subroutine calls, stepping over them, and tracing execution. Conditional breakpoints and watches on global expressions can pause a run when specified conditions or changes occur. The `x` command can pretty-print nested data; displaying lexical variables requires PadWalker version 0.08 or higher. Options can be set interactively, through `PERLDB_OPTS`, or in `.perldb` files. Documentation also describes a GUI option through Devel::ptkdb. The debugger does not provide stack-frame information for functions not compiled by Perl, such as C or C++ extension functions, and compile-time executable statements are not stopped, though some can be traced with AutoTrace. Perl is listed for Linux, macOS, and Windows, and the debugger is free.