---------------------------------------------------------------------------- COP 3610 -- EXAM 1 -- 60 POINTS MAX M. Schmalz 010220 ---------------------------------------------------------------------------- *** YOU MAY USE A TWO-SIDED 8-1/2" x 11" CRIB SHEET FOR THIS EXAM *** *** ALL OTHER BOOKS AND NOTES MUST BE PUT AWAY *** *** ANSWER ALL QUESTIONS - NO PENALTY FOR GUESSING *** NAME:______K E Y _____________________ SSN: _______________________ ANSWER EACH QUESTION WITH THE "BEST" ANSWER. PUT ANSWERS IN BLANKS NOTE: More than one answer may be true. Choose carefully. 6pts 1) State and exemplify two differences between the Korn and C shells. #1 _____Korn shell support more sophisticated control structures #2 _____Korn and C shells have different syntax (e.g., for some commands like setenv. 8pts 2) What are two advantages and two disadvantages of multiprogramming? ADV#1:__Increased CPU usage, descreased operator time___ ADV#2:__Better usage of memory - many processes_________ DIS#1:__Process starvation, if no round-robin scheduling DIS#2:__Special HW/SW required for memory protection____ 4pts 3) An operating system: C is correct answer a) links source code to machine code b) replaces operators c) provides convenient interface between user, applications, & hardware d) disassembles machine code to source code e) none of the above 8pts 4) What four new ideas did the OS/360 operating system introduce? #1:_upward compatibility_ #2:_Programmable OS with JCL #3:_cross-platform compatib#4:_SW development on one m/c 7pts 5) Discuss two differences between multiprogramming and time sharing. #1: Multiprograming does not necessarily use optimal or round-robin scheduling, does not time-slice running processes, thus can lead to process starvation #2: Time sharing can be used to present the user with an illusion of real-time or near-real-time computing on one's own machine (terminal) due to time slicing. Multiprogramming does not necessarily support this. ---------------------------------------------------------------------------- COP 3610 -- EXAM 1 -- 60 POINTS MAX M. Schmalz page 2 ---------------------------------------------------------------------------- Given the following UNIX response to the ls -l command, answer each of the questions below, ASSUMING THAT EACH LISTED COMMAND IS INDEP- ENDENT OF THE OTHER COMMANDS. If an erroneous command, write "ERROR". d-wxrw---x 1 bert student 2722 Feb 14 15:04 S01msg1.tst -rw-r--rw- 1 bert student 3533 Feb 14 15:01 S01exam1.txt drw--w-r-- 1 bert student 512 Feb 14 13:10 Projecst 3pts 6) Show permission string for chmod g+rw S01***.txt ===> _-rw-rw-rw________________ 3pts 7) Show permission string for chmod go-w S01msg1.txt ===> _file not exist - ERROR___ 3pts 8) Show permission string(s) for chmod g+x *st ===> _d-wxrwx--x (S01msg...) drw--wxr-- (Proj...) 3pts 9) How many directories (excluding . and ..) displayed for ls -al ===> _2________________________ 3pts 10) How many "w"'s in permission string(s) for chmod go-xw S01* ===> _2________________________ 3pts 11) How many "ls" entries displayed for ls -lc *ts ===> _0 -- no files end in "ts" 3pts 12) Show permission string(s) for chmod ugo+r S00*x* ===> _filename mismatch - ERROR 3pts 13) How many "r"'s in the permission string(s) for chmod gu+wr S00* ===> _filename mismatch - ERROR 3pts 14) What can user "bert" do to "S01msg.tst" after chmod ou-r S01msg.tst ===> _filename mismatch - ERROR -EOF-