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Your program is to authenticate 0Tqthe user running the program by requesting the password and validating it, then change the UID to the users UID gand the GID to the users primary GID and execute the command. The program is described further in the @=attached manual page.As always, your program must be robust. w{` Extra Credit h ( 15 points)  Modify your program in problem 1 so that is the  user  flag is given as  user.group , the GID is changed to that of  group  when  user  is a member of the group. If  user  is not a member of the  group , and the real UID is B@1root , allow the change; otherwise, deny it. 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If no user is named, the UID of T@root  is used. #+ uThe  command  may be in quotes (one argument) or may be multiple arguments. The command is run in a pristine }environment. Specifically, the  PATH  is set to search /usr/bin, /bin, /usr/sbin, /sbin, and /etc in that order; the HOME  is set to the home of  user  (again, to that of  root  if no  user  is named on the command line);  SHELL  is set "to the users login shell;  IFS  is set to tab, newline, and blank; and  TZ  is set to PDT8PST. No other environment |variables are set. All files except for standard input, output, and error are closed.All signals are reset to their default @value. (`OPTIONS ) ~ d Ignore failure of the change to the requested UID (or  root , if none). This flag is used for debugging, @6when the programmer is not running as  root . * u   user The real and effective UIDs and GIDs are to be set to those of  user  rather than  root . If  user  is an "finteger, it is handled as follows. If a user exists with that integer UID, the command acts as though othe name of the user had been typed. If no user exists with that UID, and the user executing  xsu  has wthe real UID of  root , the password requested is that of  root  and the given UID is used. If no user wexists with that UID and the user executing  xsu  does not have the real UID of  root , the command is @ refused. , ` EXIT CODE - If  command  cannot be executed,  xsu  exits with a code of 127. If  command  is executed, the program returns with  @&the return code of  command . ./` EXAMPLES /;`(xsu u bishop more /home/bishop/private 0F`[This executes the command more /home/bishop/private with  bishop s privileges. 1`xsu u nobody ed /tmp/plugh 2`fThis allows the user to edit the file /tmp/plugh with the privileges of the  nobody  user. 3k` SEE ALSO 4w` su (1) S5` HHˆRoHHˆppl}lAwslMGke1 }ArtMGl eTitle }AsMGme }lA*vlNGne3 }AuwNGoe Heading2 }AvrNGpe }$Q9#y$$ OWz e P:Numbered+ }HQ;#xzH$ OW{ eP }6Q=#y{6$ OW| eN }26Q?#z|26$ OW} eN }hQA#{h$ OW~ e }$QC#~$$ PW e P:Lettered+ }HQE#}H$ PW eP }6QG#~6$ PW eN }26QI#26$ PW eN }hQK#xh$ PW e }$QM# $$ QW e P:AnswerA+ }HQO#H$ QW eP }6QQ#6$ QW  eN }26QS#26$ QW  eN }hQU#}h$ QW  e }$j,QW#$j,$ RW  e P:AnswerA }jH,QY# jH,,$ R&eLI te Parent = UL Qxe Depth = 0 }j6,Q[# j6,$ RW eN }2j6,Q]# 2j6,$ RW eN }hj,Q_# hj,$ RW e }$ZQa# $Z$ SW e P:Answer+ }ZHQc# ZH$ SW eP }Z6Qe# Z6$ SW eN }2Z6Qg#2Z6$ SW eN }hZQi#hZ$ SW e }$.,Qk#*$.,$ TW e P:Answer }.H,Qm#.H,,$ T&eLI je Parent = UL Qre Depth = 0 }.6,Qo#.6,$ TW eN }2.6,Qq#2.6,$ TW eN }h.,Qs# h.,$ TW e }$*Q#$*$ UW eCSS Export Encoding }*Q#*$ UW  e ISO-8859-1 }h*HQ#^h*H$ UW! e }$Q#n$$ VW" eExport Encoding }Q#$ VW# e ISO-8859-1 }hHQ#hH$ VW$ e }W#|$ LGye P:ManOption }HW#H$ LGeP }6W#6$ LGeN }6W# 6$ LG eN }W#$ LGe dLeftd"Rightd Referenced dHeadingsd+HTMLd#HTMLdiHTMLdof@D QBodyBody. @@ QBody. f@D Q.Due DateBody. @@ QMapping Table Title. @@ QMapping Table Cell. f@N Q Numbered N:.\t. @@QMapping Table Title. @@ QMapping Table Cell. f@ Q Indented. @@ Q $ H l      D h  ManHeading. @@QMapping Table Cell. @@ QMapping Table Cell. @@QMapping Table Cell. @@ QHeader Double Line. f@T Q TableTitleT:Table : .  f@PQTitleBody. f@D Q.Due DateBody. f@ Q CellFooting. f@E Q BulletedBulleted. f@ Q Footnote. @@ QFooter. f@T QHeading2Body. f@T Q HeadingRunInBody. f@D QBodyBody. $f@AE Q$. 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