Please answer the following question: Read the bio below and try to give details on lee e. mcmahon 's: - death date - birth date - name - nationality - alma mater - occupation Bio: lee e. mcmahon -lrb- 1931 -- 1989 -rrb- was an american computer scientist . he was a graduate of st. louis university and obtained a ph.d. in psychology at harvard . he worked for bell labs from 1963 until 1989 , and is best known for his contributions to early versions of the unix operating system , in particular the sed stream editor . mcmahon contributed to the development of comm , qsort , grep , index , cref , cu , and datakit . and devised the mcmahon system tournament .
A:
- death date is 1989- birth date is 1931- name is lee e. mcmahon- nationality is united states- alma mater is harvard university- occupation is computer scientist