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Question 1

What does the following code do:

#include int main(void) { char str[]; int rc = scanf("%s ", str); if (rc == 1) printf("%s ", str); return 0; }

Question 1 options:

A	None of the above.
B	It crashes.
C	It reads a string from stdin and prints it to stdout.
D	It does not compile.

Question 2

What does this program print:

#include int main(int argc, char ** argv) { int res = sizeof(argc) == sizeof(int) && sizeof(argv) == sizeof(char **); if (res) printf("true "); else printf("false "); return 0; }

Question 2 options:

A	The result depends on the machine on which it is run.
B	It prints "true."
C	The result depends on what is in the command line.
D	It crashes.
E	None of the above.
F	It does not compile.
G	It prints "false."

Question 3

If the command line is

./my_pgm -t 10 my_data.dat

what is in argv[2] when ./my_pgm is run?

Question 3 options:

A	'\0'
B	None of the above.
C	NULL
D	The address of the string literal "my_data.dat".
E	The address of the string literal "10".
F	'1'
G	The address of the string literal "-t".
H	The integer 10.

Question 4

Should you use scanf or sscanf to solve this problem?

Read a sequence of integers from stdin until EOF and print the absolute value of each number read.

Question 4 options:

A	scanf
B	sscanf

Question 5

What does the following code print on a 64-bit machine?

#include void printSize(char p[]) { printf("%zu ", sizeof(p)); } int main(void) { char p[] = "Hello, World!"; printSize(p); return 0; }

Question 5 options:

A	It does not compile.
B	8
C	14
D	It crashes.

Question 6

Does this program read the command-line arguments?

int main(void) { ... }

Question 6 options:

A	Yes.
B	No.
C	Maybe.

Question 7

Does the following code read the command-line arguments?

int main(void) { int argc = 3; char const * argv[] = {"./my_pgm", "-t", "12"}; int n = 10; /* default */ int err = parseArgs(argc, argv, &n); printf("%d ", n); return err; }

Question 7 options:

A	It would, but the initializer of argv causes a syntax error.
B	Yes.
C	No.
D	It depends on what is in function parseArgs.

Question 8

What does the following program do?

#include int main(void) { double pi = 3.14159; double x; int rc; while ((rc = scanf("%lg", &x)) != EOF) { if (rc != 1) return -1; double diff = x - pi; if (-0.1 < diff && diff < 0.1) { printf("%g is close enough to %g ", x, pi); return 0; } } return 0; }

Question 8 options:

A	None of the above.
B	It reads a double from the command line.
C	It computes an approximation to {"version":"1.1","math":"$\mathrm{}$"} by Taylor series expansion.
D	It reads doubles from stdin until either EOF is reached or a number sufficiently close to {"version":"1.1","math":"$\mathrm{}$"} or something that is not a doubleis entered.

Question 9

What do scanf and sscanf return?

Question 9 options:

A	They return the number of characters read.
B	They return the number of successful assignments performed.
C	They return nothing.
D	They return 0 if successful and -1 otherwise.

Question 10

What is the problem with this code?

#include int main(void) { int * p; int rc = scanf("%d", p); return rc != 1; }

Question 10 options:

A	The return expression gives a syntax error.
B	It works just fine.
C	The pointer p does not point to a valid address.
D	The address of p should be passed to scanf (as in &p).