What is the difference between using "faillir" and "il s'en est fallu de peu que"?

Question

For example, "J'ai failli le faire" vs "Il s'en est fallu de peu que je le fasse."

Accepted Answer

Hi Dean,
They are very close in meaning , it is the difference between to be close to doing something and to almost do something.
Up to you to judge which one to use...

Answer

I don't get the 2nd one...what is exact translation?

Answer

Hi Diane,
It is indeed a very interesting impersonal expression -
S'en falloir de peu/d'un cheveu  etc. = to have been close to something by a very  little margin
Take a look at the following examples to clarify its use, often in the perfect tense and is followed by a subjunctive :
Il s'en est fallu d'un cheveu qu'ils gagnent cette élection = They came within a hair of winning this election 
Il s'en est fallu de peu que tu te fasses renverser par la voiture = You came so close to being run over by the car
Hope this helps!