argp-standalone

argp-standalone is another standalone version of the argp argument parsing functions from glibc by Thomas Mathys. It is distributed under the terms of the GNU LGPL v2.1. It is currently available in source form only from https://github.com/tom42/argp-standalone.

Missing things

• glibc compiles its argp sources using the -fexceptions option. argp-standalone currently doesn't do this; even with -fexceptions I don't think letting exceptions propagate into C code is a particularly good idea.
• gettext is currently not supported.
• Although argp-standalone contains glibc's getopt implementation it does not provide getopt through its headers. Doing so would be messy e.g. on Cygwin which provides getopt but not argp.

Compatibility

I haven't done any extensive testing, but I have successfully built version 1.0.0 and run the tests with the following compilers:

• Visual Studio 2019, both for x86 and x64
• i686-pc-windows-msvc clang 10.0.0. This is what's supplied with Visual Studio 2019. Did not run the tests since running 'nmake test' didn't do anything.
• Cygwin gcc 10.2.0 for x64, with newlib
• Cygwin clang 8.0.1 for x64, with newlib
• Cygwin i686-w64-mingw32-gcc 10.2.0
• gcc 10.2.1 for x64, on GNU/Linux, with glibc
• i686-w64-mingw32-gcc, on GNU/Linux
• x86_64-w64-mingw32-gcc, on GNU/Linux

Building examples

Using Visual Studio 2019

• This example assumes that you are doing an in-tree build
• Open e.g. a x86 Native Tools Command Prompt for VS 2019
• Change to the directory where the argp-standalone source code resides
• Run cmake, e.g. "C:\Program Files\CMake\bin\cmake.exe" -G "Visual Studio 16 2019" -A Win32 .
  • Omit the -A Win32 option to build for x64 instead of x86
• cmake should have generated argp-standalone.sln in the current directory. Open it with Visual Studio 2019

Using your host gcc

• This example assumes that you are doing an in-tree build
• Change to the directory where the argp-standalone source code resides
• Run cmake, e.g. cmake -DCMAKE_BUILD_TYPE=Release .
• Run make to build

Using MinGW

• This example assumes that you are doing an in-tree build and that your MinGW gcc is called i686-w64-mingw32-gcc
• Change to the directory where the argp-standalone source code resides
• Run cmake, e.g. cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_C_COMPILER=i686-w64-mingw32-gcc .
• Run make to build

Possible improvements for future versions

• Factor out duplicated ad hoc implementations of what's basically basename (search for occurrences of ARGP_PATH_SEPARATOR). Provide better implementations where possible. The current implementation has various shortcomings:
  • On Windows it only recognizes \ as the path separator, but should probably recognize both \ and /
  • It returns an empty string if the path ends with the path separator. This is normally not the case but I've seen it happening.
• Fix the preprocessor #warning in __argp_short_program_name:
  • On Windows we could fall back to GetModuleFileName
• gettext support

History

• 2020-12-29: Version 1.0.0, based on glibc 2.24.
  glibc 2.24 was simpler to get going than the back then current glibc 2.32. Functionally there should not be much of a difference.