Bobby Shmurda has just been sentenced to 4 years in prison for having a shank, but the good news for him ... it doesn't mean extra time behind bars.
The rapper -- who is already serving 7 years for his murder conspiracy conviction -- appeared in court with attorney Paul London Friday and pled guilty to the crime of attempted promoting prison contraband.
The new sentence runs concurrently ... meaning it won't be tacked on to his 7 year sentence.
As we reported ... sources close to Bobby say friends, family and lawyers all pushed him to take the deal. Bobby's been in jail since December 2014, so he's already taken a chunk out of his sentence.