In this short story, two men -- one more by the book and the other less so -- are the crew on a cargo ship. An accident takes out their oxygen reserves, leaving only enough for one of them to make it back. One detail I can recall: the more easygoing one allows himself the occasional cigarette, infuriating his crewmate. Only the easygoing one survives, and it's one of those mystery reveal type stories where we find out the end of the story before we learn what happened. It possibly may be by Arthur C. Clarke, but just as possibly not. It's driving me nuts not being able to remember! Thank you in advance!
You are describing Breaking Strain by Arthur C. Clarke.
Two men (Grant and McNeil) are the only crew of a cargo ship, whose oxygen reserves are lost when a meteor hits the refrigeration coils.
Grant discovers that McNeil has been smoking:
Nothing could have been more trivial than that which made Grant pause in the corridor outside McNeil's room. In the ordinary way he would not even have noticed it. It was the smell of tobacco smoke.
The thought that the sybaritic engineer had so little self-control filled Grant with blinding fury. He stood for a moment quite paralyzed with the intensity of his emotion.
- Grant attempts to murder McNeil, and then the narration skips forwards to the ship being rescued, where it is revealed that McNeil, not Grant, was the sole survivor. The narration then goes back and shows how things played out.