1. Cs288 Intensive Programming in Linux
Instructor: C F Yurkoski
Section web site:
Class 8

2. today homework revu scanf Pointers Bit operations FILE operations
Macros
Typedefs
malloc() and free()
Linked lists
C lib
Recursion
In class exercises
cfy

3. homework Do exercise 1-19 from the text.
Redo problem 4 from class 2 as a C program
Write a program which reads stdin and converts any local case characters to upper
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4. 1-19
write a function called reverse(s) which reverses the character string s. Use it to write a program which reverses its input. solution at:
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5. cfy

6. cfy

7. cfy

8. 1-21
write a program that replaces blanks with the minimum number of tabs and blanks.
soluton at:
cfy

9. cfy

10. Problem3 https://web.njit.edu/~yurkowsk/x/prob3A.c
cfy

11. toupper.c https://web.njit.edu/~yurkowsk/x/toupper.c
#include <stdio.h> main(){ char c; while((c=getchar())!=EOF){ if(c>='a' && c <= 'z') c+='A'-'a'; putchar(c); }
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12. scanf Format similar to printf %d, %s, %x etc.
int scanf(const char *restrict format, ... );
%d, %s, %x etc.
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13. example
#include <stdio.h> main(){ char action[6]; int word; while(scanf("%s %d",action,&word)!=EOF){ fprintf(stderr,"%s %d\n",action,word); if(!strcmp(action,“DO")) fprintf(stderr, “do something%x\n",word); else “reverse action %x\n",word); }
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14. >: echo “DO 666" |. /a. out add 10 add a >: echo “UNDO 7" |. /a
>: echo “DO 666" | ./a.out add 10 add a >: echo “UNDO 7" | ./a.out delete 7
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15. pointers char c='a', d='b', *cp; cp= &d; *cp=c; printf("%c %c\n",c,d);
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16. Referencing structures
typedef struct string string; struct string{ struct string *forward; int data; }a[SZ]; a[i].forward=&a[i+1];
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17. Using pointers w/ structures
struct list{
struct list *l;
int payload;
}array[SIZE];
struct list *lp;
lp=array;
lp->payload=data[10];
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18. BIT OPERATIONS int x, y, z; x&=7; z=y|x; z=y<<2; if(y^x); x=~y;
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19. FILE I/O fopen() and friends (fwrite(), fread(), fseek() etc.
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20. FILE *f; f=fopen("/tmp/yurkoski","w"); fprintf(f,“msg");
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21. Code macros e.g.: #define sum(a,b) (a+b)
#define macro-name(args) (expression)
e.g.:
#define sum(a,b) (a+b)
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22. #include <stdio.h> #include <stdlib.h>
#define cube(a) (a*a*a) /* no semicolon*/
main(int argc, char *argv[]) {
int a;
if(argc != 2){
fprintf(stderr,
"usage: %s n\n",argv[0]);
exit(-1); }
a=atoi(argv[1]);
printf("the cube of %d is %d\n",
a, cube(a));
6-9-15

23. Revu typedefs Used to define you own types
syntax: typedef {structure-def}typedef-name;
Usage:
typedef-name variable-name;

24. typedef struct {
int fill;
char name[8];
}frame;
frame *p;
p=(frame *)malloc(SIZE*sizeof(frame));
p++;
p->fill=fill;

25. #include <stdlib.h> #define SIZE 10 typedef struct { int fill;
char name[8];
}frame;
main() {
frame *p, *q, fill;
char cmd[10];
q=p=malloc(SIZE*sizeof(frame));
6-9-15

26. Linked list Singly linked lists Doubly linked lists
Circularly linked lists
Multiply linked lists
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27. Singly linked lists
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28. Doubly linked lists
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29. C library
atoi()
itoa()
atof()
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30. Recursion
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31. In class problem 1
Write a C program which accepts as a command line argument an integer and reads another integer from standard input and bit wise or the two together and writes the result (converted to an ascii string) to a file in the in /tmp whose name is your student id number.
Put your source code in moodle.

32. example
if the file /tmp/x contains a 5, and your id is 666 cc yourprogm.c –o yourprogm cat /tmp/x | yourprogm 6 should write the ascii string 30 to the file 666 in the current directory.

33. In class problem 2
Write a program which reads a series of integers for standard input until an EOF is encountered.
Store them in a linked list in sorted order.
Upon encountering the EOF, output the items on the list.