????? ?????? (assert)

1
????? 3

• ?????
• ????? ?????? (assert)

??-?? ???? litalma_at_cs.technion.ac.il ???? ?''?
???? ????????
2
????? - Structures

• struct ltstruct namegt
• lttype name1gt ltfield1gt
• lttype name2gt ltfield2gt
• .
• .
• lttype namengt ltfieldngt
• ????????? ?? ???? ?????? ?? ???? ????? ????????
  ?????
• ??? ????? ??????? ????? ?"? ????? ???????? ??????
• ?????? ?????
• ????? ?? ??????? ????? ?????
• ????? ??? ???? ??????? - ???????? ??????? ?? ??
  ????? ???????

3
????? - Structures

• ????? ?????
• struct ltstruct namegt ltvariable namegt
• ????? - ???? ?????? ???? ?????. ?????? ??????
  ?????? ?? ????? ?????.
• struct Date_t
• int day
• char month4
• int year
• ????? ????? ???? date
• struct Date_t d

Why 4 chars ?
4
????? ??? ?????

• int start_day, start_year
• int end_day, end_year
• char start_month4, end_month4
• int compare_dates(int day1, char month1, int
  year1, int day2, char month2, int year2)
• ...
• compare_dates(start_day, start_month, start_year,
• end_day, end_month, end_year)

5
????? ?? ?????

• struct Date_t start
• struct Date_t end
• int compare_dates(struct Date_t date1,
• struct Date_t date2)
• ...
• compare_dates(start,end)
• ???? ??? ????
• ???? ???? ????
• ???? ???????? ????????? ??? ????
• ???? ????? ??????? ??? ????????

6
????? - Structures

• ????? ???? ???? ????? ???? struct ????? ?"?
• ltvariable namegt.ltfield namegt
• ???? ???? ????? ?struct-, ???? ???? ???? ?????
  ?????
• (ltpointer namegt).ltfield namegt
• ?????? ???? ?? ???????, ????? ??? ????? ??????
  ???? ???? ????
• ltpointer namegt -gt ltfield namegt
• ?????
• struct Date_t p
• pd
• p-gtday12 / or (p).day12 /

7
????? - Structures

• ?????? ?????
• int main()
• struct Date_t date , pdate
• date.day 21
• strcpy(date.month , "NOV")
• pdate date
• pdate-gtyear 1971
• printf ("The year is d\n",date.year)

8
?? ???? ??????

• ?????? ?????? ???? ????? ??? struct Date_t
• ???? ?????? ?????? ?????? struct ?? ???, ???? ???
  ?????? ??? ?? ???? ?????? ???? ??? ????, ????
  Date
• ??? ????? ???? ??????? ??????, ????? ???? ???
  ???????? ???????????? ?? ????
• int i
• char c
• Date date
• ?-C ?????? ?????? ?? ???? ?''? typedef

Date ??? ?? ???? ?-struct Date_t
9
?? ???? ?????? ??????? typedef

• typedef ltold type namegt ltnew type namegt
• ?????? ????? ?? ???? ??? ???? ?? ?????
• ???? ?????? ??? ????? ???????? ????? ?????
• ??????
• typedef int ID
• typedef int Element
• ...
• ID i
• Element element

??? ?- int i int element
10
?? ???? ????? ??????? typedef

• typedef struct Date_t Date
• ???? ?? ?????? ????? ?? ????? ?????
• typedef struct Date_t pDate
• ??
• typedef Date pDate
• ???? ???? ?? ????? ????? ?????? ?? ???? ???
• typedef struct Date_t
• int day
• char month4
• int year
• Date
• typedef Date pDate

11
????? ????? ???? ????

• ???? ?????? ???? ???? ??? ?????? ???? ???
• typedef struct Date_t
• int day
• char month4
• int year
• Date
• typedef struct Person_t
• char name
• int height
• Date birth
• Person
• ???? ???? ?? ????? ??????
• Person p
• Person ppp
• p.birth.year 1994
• pp-gtbirth.year 1994
• ???? ?? pp-gtbirth-gtyear ?

12
????? ?????? ????? ???? ????

• ????? ?????? ?? birth ???? ??????Date ???? ???
  ??????? ?????? ????? ?????? Date
• typedef struct Person_t
• char name
• int height
• Date birth
• Person
• ???? ???? ?? ????? ??????
• Person p
• Person ppp
• p.birth-gtyear 1994
• pp-gtbirth-gtyear 1994
• ??? ?? ???? ?????? ?? p Person?? ????? ????
  ???? ???? ????? ?????? Date ??? ?????? ????
• ??? ??? ???? ????? ???? ???? !
• ???? ???? ??????

13
????? ????????? ?????

• ?????? ???? ???? ?????? ???????? ?????? ?????
  ????? ????
• typedef struct Date_t
• int day
• char month4
• int year
• struct Date_t next
• Date
• ???? ????? ????? ?? ?????? ?? ???? ??? ?????
  ????? ???? ?????
• int main()
  
• Date dt1, dt2, pdt
• dt1.day 31 dt1.year 1992
• strcpy(dt1.month,DEC)
• dt2.day 1 dt2.year 1993
• strcpy(dt2.month,JAN)
• pdt dt2
• dt1.next dt2
• printf ("Year in dt1 d\n Year in dt2 d\n
  ",dt1.year, (dt1.next)-gtyear)

14
????? ??????? ???? ????? ?????? ??????

• ???? ????? ?? ???? ?? ???? year ?? ?????? dt2
  ???? ??????
• dt2.year 1994
• pdt?year 1994
• (dt1.next) ?year 1994
• ????? ??? ????? ?????? ?? ??? ??????
• ?? ???? ????? ???? ?? ???? next ?-dt ??? ????
  ???? ???? ?????

pdt
15
????? ?????? ?? ????? ??????? ????? ?????

• ?????
• ???? ????? ????? ???????? ???? ?? ???? ??
  ???????, ???????? ???? ???? ???? ??????
• ?????
• ????? ?????? ?? ???????

16
????? ?????? ?? ????? ??????? ????? ?????
??? ?????? ?????? ?

• int main()
• Date top NULL, tmp NULL
• int day, year
• char month4
• while (scanf("d s d", day ,month , year) !
  EOF)
• tmp (Date) malloc(sizeof(Date))
• if (tmp NULL)
• free_date_list(top) exit(0)
• tmp-gtday day tmp-gtyear year
• strcpy(tmp-gtmonth ,month)
• tmp-gtnext top top tmp
• print_date_list(top)
• return 0

?? ??? ???? ???????? ?
17
????? ?????? ?? ????? ??????? ????? ?????

• void free_date_list(Date top)
• while (top ! NULL)
• Date tmptop
• toptop-gtnext
• free(tmp)

18
????? ?????? ?? ????? ??????? ????? ?????

• void print_date_list(Date top)
• Date tmp top
• while (tmp ! NULL)
• printf("d s d\n",
• tmp-gtday, tmp-gtmon, tmp-gtyear)
• tmp tmp-gtnext

19
??????? ???? ?????

• int main()
• Date top NULL, tmp NULL
• int day,year
• char month4
• while (scanf("d s d", day ,month , year) !
  EOF)
• tmp (Date) malloc(sizeof(Date))
• if (tmp NULL)
• free_date_list(top) exit(0)
• tmp-gtday day tmp-gtyear year
• strcpy(tmp-gtmonth ,month)
• tmp-gtnext top top tmp
• print_date_list(top)
• return 0

int main() Date top NULL Date
date while (scanf("d s d", date.day
,date.month , date.year) 3) Date
tmp (Date) malloc(sizeof(Date)) if (tmp
NULL) free_date_list(top)
exit(0) tmp date
tmp-gtnext top top tmp
print_date_list(top) free_date_list(top)
return 0
20
????? ????? ?????? ?????? ????????

• ????? ?????? ??????? ??????? ????????? ????
  ?????? ?????.
• ???????
• ???? ???? ????? ??????? ?????????
• ????? ???????
• ???? ?? ????? ????? ???? ??????? ????????? ???
  ????? ??????
• ????? ????? ???????? events
• 1 JAN 404 Last gladiator competition
• 6 MAY 1889 Eiffel tower opens
• 21 NOV 1794 Honolulu harbor discovered
• 1 JAN 1852 First US public bath opens
• 2 MAR 1969 First takeoff of the Concorde
• 6 MAY 1915 Orson Welles is born
• 6 MAY 1626 Manhattan purchased for 1000
• 2 MAR 1969 First landing of the Concorde

21
????? ????? ?????? ?????? ????????

• ????? ??????? ????? ??????
• gt important_dates events
• enter date 2 MAR 1969
• First takeoff of the concorde
• First landing of the concorde
• enter date 23 NOV 1999
• Nothing special

22
????? ?????
historicalDateList
event

• ????? ????? ?????? ?? ???????
• ??? ????? ????? ????? ?? ??????? ???? ?????? ??

date
events list
next
date
events list
next
23
?????

• ??????
• define MAX_LINE_LENGTH 100
• ???? ?????
• typedef struct Date_t
• int day
• char month4
• int year
• Date

24
?????

• ???? ?????
• typedef struct Event_t
• char description
• struct Event_t next
• Event

???? ?? ????? ?????? ?? ?????. description ????
???? ???? d,des,desc,dsc ?? ???? ??????
??????/????? ??????? dscrptn,descript
25
?????

• ???? ????? ???????
• typedef struct HistoricalDate_t
• Date date
• Event eventList
• struct HistoricalDate_t next
• HistoricalDate

26
???????? ??? ????? ????

• ????? ????? ????? ??? ???? (????? ?????? ???????
  ????? ???????? !)
• int readDate(FILE inputFile, Date date)
• if (inputFile NULL date NULL)
• return 0
• if (fscanf (inputFile, d s d ,
  (date-gtday),date-gtmonth,
• (date-gtyear))3)
• return 1
• return 0

27
???????? ??? ????? ????

• ????? ???? ????? ??????? ????? ??? ????. (?????
  ??????, ???????? ?????? ?????? ??????? ?????
  ???????? !)
• int readEvent(FILE inputFile, Date date, char
  buffer)
• if (inputFile NULL date NULL
  buffer NULL)
• return 0
• if (readDate(inputFile,date) 0)
• return 0
• if(fgets(buffer, MAX_LINE_LENGTH,
  inputFile)NULL)
• return 0
• return 1

28
???????? ??? ????? ???? ????? ???????

• Event allocateEvent(char description)
• Event newEvent
• if (description NULL) return NULL
• newEvent(Event)malloc(sizeof(Event))
• if (newEvent NULL) return NULL
• newEvent-gtdescription(char)malloc(strlen(desc
  ription)1)
• if (newEvent-gtdescription NULL)
• free (newEvent)
• return NULL
• strcpy(newEvent-gtdescription, description)
• newEvent-gtnext NULL
• return newEvent

29
???????? ??? ????? ???? ????? ???????

• HistoricalDate allocateHistoricalDate(Date date)
  
• HistoricalDate newHistoricalDate
• (HistoricalDate) malloc(sizeof(HistoricalDate)
  )
• if (newHistoricalDate NULL)
• return NULL
• newHistoricalDate -gtdate date
• newHistoricalDate -gteventList NULL
• newHistoricalDate -gtnext NULL
• return newHistoricalDate

30
???????? ??? ????? ????? ??????? ?????? ???????

• HistoricalDate find(HistoricalDate first, Date
  date)
• if (first NULL)
• return NULL
• if (first-gtdate.day date.day
• strcmp(first-gtdate.month,date.month) 0
• first-gtdate.year date.year)
• return first
• return find(first-gtnext,date)

31
???????? ??? ????? ????? ??????? ?????????

• void printEvents(Event event)
• if (event NULL )
• return
• printf (s\n, event-gtdescription)
• printEvents(event-gtnext)

32
???????? ??? ????? ???? ???????

• HistoricalDate readEvents(FILE inputFIle)
• char bufferMAX_LINE_LENGTH
• Date date
• HistoricalDate firstHistoricalDate NULL ,
  currentHistoricalDate NULL
• Event event NULL
• while (readEvent(inputFIle,date,buffer))
• currentHistoricalDate find(firstHistoricalDat
  e ,date)
• if (currentHistoricalDate NULL) / in
  case the date doesn't exist
• add this date to be the first in the
  list /
• currentHistoricalDate allocateHistoricalDate
  (date)
• if (currentHistoricalDate NULL)
• return NULL
• currentHistoricalDate-gtnext
  firstHistoricalDate
• firstHistoricalDate currentHistoricalDate
• event allocateEvent(buffer)
• if (event NULL)
• return NULL

33
??????? ??????

• int main(int argc, char argv)
• FILE inputFile NULL
• HistoricalDate historicalDateList NULL ,
  historicalDate NULL
• Date date
• if (argc ! 2)
• return 1
• if ((inputFIle fopen(argv1,r))NULL)
• return 2
• historicalDateList readEvents(inputFile)
  /creating the list/
• fclose(inputFile)
• if (historicalDateList NULL)
• return 3
• while (readDate(stdin,date))
• historicalDate find(historicalDateList
  ,date)
• if (historicalDate NULL)
• printf (Nothing special\n)
• else
• printEvents(historicalDate-gteventList)

34
???????? ???????

• ????? ??????? ???? ???????.
• ????? ??????? ???? ????? ????? ???? ????? ?????
  ???? ???????? readEvents.
• ?????? ????? ?????? ??????.
• ????? ????? ??? ???????? ???? ????? ????? define
  ?? enum

35
????? ?????? - assert

• ??? ????? ????? ?????? ?????? ???? ????? ?????
• ????? ?????? ????? ???? ?????? ??????? ?????
  ?????? ?????? ?????? ??????
• ?-C ????? ?''? ????? ?????? assert????? ?????
  ?????? ?-int
• ????? ?-assert.h
• ?????? ???????? ???? ???? ??????

36
????? ?????? - assert

• prog.c
• int main(int argc, char argv)
• ...
• if(argc gt 3)
• ...
• else if (argc lt 2)
• ...
• else
• / if we are here argc is 2 /
• ...
• ...

assert(argc 2)
37
????? ?????? - assert

• gt gcc prog.c -o prog
• gt prog
• gt prog a
• gt prog a b c
• gt prog a b
• prog prog.c12 main Assertion argc 2'
  failed.
• Abort
• gt

38
????? ?????? - assert

• ??????? ?? ??????? ??????? ????? ??????? ?????
  ????? ?????? ??
• ????? ??? ???????
• ????? ?????
• ?? ?????
• ???? ????
• ?? ????????

39
????? ?????? - assert

• ???? ???? ?? ?????? asserts?''? ?????? ?? ???
  -DNDEBUG
• gt gcc DNDEBUG prog.c -o prog
• gt prog a b
• gt
• ???? ?????? ?? ???? ??? ????? ?????
  (production version)
• asserts ??????? ?? ????? ????? (development
  version)
• ?????? ????????? ?? ?????? ???? ???????? ????????
  ?? ???? ???
• ????? ?????? ?-asserts ???? ????? ?? ?????? ????

40
????? ?????? ????? ?? ????

• ????? ?-assert ??? ????? ?????? ??????? ?? ?????
  ?? ?? ????? ?????
• int main(int argc, char argv)
• assert(argc 2) / the program must be called
  with only one parameter /
• ...

if(argc ! 2) fprintf(stderr, the program
must be called with ) fprintf(stderr,
only one parameter\n) exit(0)
41
????? ?????? ????? ?? ????

• FILE fd fopen(input.txt" , "r")
• assert(fd ! NULL)

if(fd NULL) error(Failed to open
input.txt!\n)
42
????? ?????? ????? ?? ????

• ????? ???????, ??????? ?????? ??????? ????
  ?assert-
• assert((result calculate()) gt MIN_RESULT)
• / working with result /
• ...
• ?-production version ?assert- ?? ????? ???????
  ????? ?? ????? !

43
????? ?????? ????? ????

• result calculate()
• assert(result gt MIN_RESULT)
• / working with result /
• ...