OPT: add main to avoid system calls
OPT: add main to avoid system calls

Former-commit-id: 8e48299bfff22de32504d13bac4197d047e7fc39 [formerly ebec626b3ab8ce21e397dbb1ec8d771c6ac91fe6]
Former-commit-id: a220570ee05087c3e242466d22b2d5bf5b853b79
Former-commit-id: 5606b5468b9e72cba9aa330e0a39505fd469a838
neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox,neuropoly/spinalcordtoolbox