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stringlengths 24
24
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stringlengths 24
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stringclasses 5
values | feature_version
stringclasses 2
values | input_question
stringlengths 1
1.24k
⌀ | input_code
stringlengths 2
18.5k
⌀ | input_intention
stringlengths 1
2.48k
⌀ | input_task_description
stringlengths 18
3.32k
⌀ |
|---|---|---|---|---|---|---|---|
63c647a55f004bf4898cf57c | 2023-02-15T19:22:52.915Z | Help Fix Code | v1 | null | typedef struct user {
char name[MAX_NAME];
char profile_pic[MAX_NAME];
struct post *first_post;
struct user *friends[MAX_FRIENDS];
struct user *next;
} User;
User user1;
char user1.profile_pic[20]; | initialize user1.profile_pic to an empty array | null |
63c647a55f004bf4898cf57c | 2023-02-15T19:24:07.359Z | Help Fix Code | v1 | null | typedef struct user {
char name[MAX_NAME];
char profile_pic[MAX_NAME];
struct post *first_post;
struct user *friends[MAX_FRIENDS];
struct user *next;
} User;
User user1;
char user1.profile_pic[20]; | declare user1.profile_pic to be an array of char | null |
63c647a55f004bf4898cf57c | 2023-02-15T20:47:52.732Z | General Question | v1 | value of true | null | null | null |
63c647a55f004bf4898cf57c | 2023-04-06T21:58:37.321Z | Explain Code | v2 | null | strlen(NULL); | null | null |
63c647a55f004bf4898cf57c | 2023-04-06T22:12:19.600Z | Explain Code | v2 | null | char s[3];
sprintf(s, "%s", NULL); | null | null |
63c647a55f004bf4898cf581 | 2023-01-17T15:09:39.544Z | Question from Code | v1 | Is there any problem of this code? | int main() {
return 0;
} | null | null |
63c647a55f004bf4898cf581 | 2023-01-17T15:10:54.560Z | General Question | v1 | write a socket program that can transfer information | null | null | null |
63c647a55f004bf4898cf581 | 2023-01-28T18:46:02.605Z | General Question | v1 | do i need to free the pointer returned by ctime() | null | null | null |
63c647a55f004bf4898cf581 | 2023-01-28T18:46:21.534Z | General Question | v1 | what is a static variable? | null | null | null |
63c647a55f004bf4898cf581 | 2023-03-14T15:36:29.947Z | Question from Code | v2 | What does this code do? | int (*complex(int index))(char *s, int l); | null | null |
63c647ab5f004bf4898cf5a9 | 2023-01-24T21:31:28.693Z | Question from Code | v1 | Why does this code generate a seg fault | 8 void fib(int **fib_sequence, int n) {
19 *fib_sequence = malloc(sizeof(int) * n);
20 for (int i = 0; i < n; i++) {
21 if (i < 2) {
22 *fib_sequence[i] = i;
23 } else {
24 *fib_sequence[i] = *fib_sequence[i - 2] + *fib_sequence[i - 1];
25 }
26 }
27 } | null | null |
63c647ab5f004bf4898cf5a9 | 2023-01-24T22:21:14.309Z | Question from Code | v1 | Why does this code only look at the first argument of the list? | int **split_array(const int *s, int length) {
14 int **main_array = malloc(sizeof(int *) * 2);
15 main_array[0] = malloc(sizeof(int) * length / 2);
16 main_array[1] = malloc(sizeof(int) * length / 2);
17
18 for (int i = 0; i < length; i++) {
19 if (i % 2 == 0) {
20 main_array[0][i] = s[i];
21 } else {
22 main_array[1][i] = s[i];
23 }
24 }
25
26 return main_array;
27 } | null | null |
63c647ab5f004bf4898cf5a9 | 2023-01-24T22:22:16.167Z | Question from Code | v1 | Does line 2 correctly create a pointer to an array of two dynamically allocated arrays of ints? | int **split_array(const int *s, int length) {
14 int **main_array = malloc(sizeof(int *) * 2);
15 main_array[0] = malloc(sizeof(int) * length / 2);
16 main_array[1] = malloc(sizeof(int) * length / 2);
17
18 for (int i = 0; i < length; i++) {
19 if (i % 2 == 0) {
20 main_array[0][i] = s[i];
21 } else {
22 main_array[1][i] = s[i];
23 }
24 }
25
26 return main_array;
27 } | null | null |
63c647ab5f004bf4898cf5a9 | 2023-01-24T22:23:12.133Z | Question from Code | v1 | Does line 2 correctly create a pointer to an array of two dynamically allocated arrays of ints? | int **split_array(const int *s, int length) {
14 int **main_array = malloc(sizeof(int) * 2);
15 main_array[0] = malloc(sizeof(int) * length / 2);
16 main_array[1] = malloc(sizeof(int) * length / 2);
17
18 for (int i = 0; i < length; i++) {
19 if (i % 2 == 0) {
20 main_array[0][i] = s[i];
21 } else {
22 main_array[1][i] = s[i];
23 }
24 }
25
26 return main_array;
27 } | null | null |
63c647ab5f004bf4898cf5a9 | 2023-01-24T22:25:13.623Z | Help Fix Code | v1 | null | 13 int **split_array(const int *s, int length) {
14 int **main_array = malloc(sizeof(int) * 2);
15 main_array[0] = malloc(sizeof(int) * length / 2);
16 main_array[1] = malloc(sizeof(int) * length / 2);
17
18 for (int i = 0; i < length; i++) {
19 if (i % 2 == 0) {
20 main_array[0][i] = s[i];
21 } else {
22 main_array[1][i] = s[i];
23 }
24 }
25
26 return main_array;
27 } | line 2 should create a pointer to an array of two dynamically allocated arrays of ints | null |
63c647ab5f004bf4898cf5a9 | 2023-01-25T00:01:43.240Z | Help Fix Code | v1 | null | int **split_array(const int *s, int length) {
int **main_array = malloc(sizeof(int *) * 2);
main_array[0] = malloc(sizeof(int) * (length / 2 + length % 2));
main_array[1] = malloc(sizeof(int) * (length / 2));
for (int i = 0; i < length; i++) {
if (i % 2 == 0) {
main_array[0][i / 2] = s[i];
} else {
main_array[1][i / 2] = s[i];
}
}
return main_array;
} | why does this overallocate memory on odd length arrays | null |
63c647ab5f004bf4898cf5a9 | 2023-01-25T14:49:13.252Z | Help Fix Code | v1 | null | int **split_array(const int *s, int length) {
int **main_array = malloc(sizeof(int *) * 2);
main_array[0] = malloc(sizeof(int) * (length / 2 + length % 2));
main_array[1] = malloc(sizeof(int) * (length / 2));
for (int i = 0; i < length; i++) {
if (i % 2 == 0) {
main_array[0][i / 2] = s[i];
} else {
main_array[1][i / 2] = s[i];
}
}
return main_array;
} | This code should allocate the correct amount of memory to each of the 2 arrays based on the length of the input array. For example, if the array is length 3, it should allocate sizeof(int) * 2 to the first array and sizeof(int) to the second | null |
63c647ab5f004bf4898cf5a9 | 2023-02-04T18:29:36.379Z | Help Fix Code | v1 | null | int create_user(const char *name, User **user_ptr_add) {
17
18 // Check the sizeof the name array
19 if (strlen(name) > 31) {
20 // Name is too long
21 return 2;
22 }
23
24 // Initialize a new user with name pointing to NULL
25 User new_user;
26 strcpy(new_user.name, name);
27 new_user.next = NULL;
28
29 // Check if there are no users currently in the list
30 if (*user_ptr_add == NULL) {
31 *user_ptr_add = &new_user;
32 return 0;
33 }
34
35 // Create a temp variable to iterate over the list
36 User *curr = *user_ptr_add;
37
38 while (curr != NULL) {
39
40 // Check if this is the end of the list
41 if (curr->next == NULL && curr->name != name) {
42 // Insert the new user
43 curr->next = &new_user;
44 } else if (curr->name != name) {
45 // If the name isnt taken, keep iterating
46 curr = curr->next;
47 } else {
48 // The name is taken
49 return 1;
50 }
51 }
52
53 // Successfully added the new user
54 return 0;
55 } | For some reason, this is not correctly adding a new user to the list of users | null |
63c647ab5f004bf4898cf5a9 | 2023-02-04T18:34:34.816Z | Help Fix Code | v1 | null | int create_user(const char *name, User **user_ptr_add) {
17
18 // Check the sizeof the name array
19 if (strlen(name) > 31) {
20 // Name is too long
21 return 2;
22 }
23
24 // Initialize a new user with name pointing to NULL
25 User new_user;
26 strcpy(new_user.name, name);
27 new_user.next = NULL;
28
29 // Check if there are no users currently in the list
30 if (*user_ptr_add == NULL) {
31 *user_ptr_add = &new_user;
32 return 0;
33 }
34
35 // Create a temp variable to iterate over the list
36 User *curr = *user_ptr_add;
37
38 while (curr != NULL) {
39
40 // Check if this is the end of the list
41 if (curr->next == NULL && curr->name != name) {
42 // Insert the new user
43 curr->next = &new_user;
44 } else if (curr->name != name) {
45 // If the name isnt taken, keep iterating
46 curr = curr->next;
47 } else {
48 // The name is taken
49 return 1;
50 }
51 }
52
53 // Successfully added the new user
54 return 0;
55 } | How do I allocate memory when creating the user struct | null |
63c647ab5f004bf4898cf5a9 | 2023-02-08T02:48:41.839Z | Help Fix Code | v1 | null | struct pixel **read_pixel_array(FILE *image, int pixel_array_offset, int width, int height) {
36
37 // Step 1
38 struct pixel **pixel_array = malloc(sizeof(struct pixel) * height);
39
40 // Step 2
41 for (int i = 0; i < height; i++) {
42 pixel_array[i] = malloc(sizeof(struct pixel) * width);
43 }
44
45 // Step 3
46 fseek(image, pixel_array_offset, SEEK_SET);
47 for (int i = 0; i < height; i++) {
48 for (int j = 0; j < width; j++) {
49 struct pixel new_pixel;
50 fread(&new_pixel, sizeof(struct pixel), 3, image);
51 pixel_array[i][j] = new_pixel;
52 }
53 }
54 return pixel_array;
55 } | this code should read input from a binary file and add it into the pixel array | null |
63c647ab5f004bf4898cf5a9 | 2023-02-08T16:43:38.027Z | Help Fix Code | v1 | null | char picture[MAX_NAME];
262 FILE *profile = fopen(user->profile_pic, "r");
263 fgets(picture, MAX_NAME, profile);
264 printf("%s\n", picture); | Print the contents of an ASCII file | null |
63c647ab5f004bf4898cf5a9 | 2023-02-08T16:45:32.777Z | Help Fix Code | v1 | null | char picture[MAX_NAME];
262 FILE *profile = fopen(user->profile_pic, "r");
263 fgets(picture, MAX_NAME, profile);
264 printf("%s", picture); | This code should print the entire file, but it only prints the first line | null |
63c647ab5f004bf4898cf5a9 | 2023-02-08T17:25:59.545Z | Help Fix Code | v1 | null | strcpy(new_post->contents, contents); | I am attempting to copy contents, which is type char * and allocated on the heap to contents, which is also type char *
| null |
63c647ab5f004bf4898cf5a9 | 2023-02-15T16:23:40.902Z | Help Fix Code | v1 | null | char *copy(char *dest, const char *src, int capacity) {
16
17 int i;
18 for (i = 0; i < capacity && src[i] != '\0'; i++) {
19 dest[i] = src[i];
20 }
21
22 for (; i < capacity; i++) {
23 dest[i] = '\0';
24 }
25
26 return dest;
27 } | This should work just the same as strncpy | null |
63c647ab5f004bf4898cf5a9 | 2023-02-28T02:00:56.099Z | Help Fix Code | v1 | null | /* Read from the open file fp, and create the linked data structure
9 that represents the Makefile contained in the file.
10 See the top of pmake.h for the specification of Makefile contents.
11 */
12 Rule *parse_file(FILE *fp) {
13 // Implement this function and remove the stubbed return statement below.
14
15 // Initialize the head node
16 Rule *head = malloc(sizeof(Rule));
17
18 // Initialize the variable to store the output from each line of the file
19 char output[MAXLINE];
20
21 // Create a variable to iterate over
22 Rule *curr = head;
23
24 // Traverse the file
25 while (fgets(output, MAXLINE, fp) != NULL) {
26
27 // Check if it's a target
28 if (output[0] != '\t' && is_comment_or_empty(output) == 0) {
29 // printf("%s", output);
30 // Find the target from the current line
31 char *ptr = strchr(output, ':');
32
33 // Copy the length of ptr - 1 to the target variable
34 int size = strlen(ptr) - 1;
35 curr->target = malloc(sizeof(char) * size);
36 strncpy(curr->target, ptr, size - 1);
37 curr->target[size] = '\0';
38
39 // TODO: Properly initialize rest of struct
40 curr->dependencies = NULL;
41 curr->actions = NULL;
42 curr->next_rule = malloc(sizeof(Rule));
43 curr = curr->next_rule;
44
45 // Otherwise it's an action line
46 } else if (output[0] == '\t' && is_comment_or_empty(output) == 0) {
47 // If its an action, parse the args into
48 // a heap allocated list
49 // TODO: Delete:
50 // printf("%s", output);
51 }
52 }
53
54 return head;
55 } | Currently, this code always produces a segmentation fault | null |
63c647ab5f004bf4898cf5a9 | 2023-02-28T02:44:41.414Z | Help Fix Code | v1 | null | char *output;
char *ptr = strchr(output, ':');
32
33 // Copy the length of ptr - 1 to the target variable
34 int size = ptr - output; | this code is meant to find the length of the string before the colon | null |
63c647ab5f004bf4898cf5a9 | 2023-02-28T02:45:43.892Z | Help Fix Code | v1 | null | char *output;
char *ptr = strchr(output, ':');
32
33 // Copy the length of ptr - 1 to the target variable
34 int size = ptr - output - 1; | this code is meant to find the length of the string before the colon | null |
63c647ab5f004bf4898cf5a9 | 2023-03-09T20:53:34.549Z | Help Fix Code | v2 | This code is meant to read 2 lines from standard input, and send them to the child. The child is then meant to execute the validate process with the user and password sent from the parent and return an exit code. Currently, when run the code is on an infinite loop | #include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>
#define MAXLINE 256
#define SUCCESS "Password verified\n"
#define INVALID "Invalid password\n"
#define NO_USER "No such user\n"
int main(void) {
char user_id[MAXLINE];
char password[MAXLINE];
/* The user will type in a user name on one line followed by a password
on the next.
DO NOT add any prompts. The only output of this program will be one
of the messages defined above.
Please read the comments in validate carefully
*/
if(fgets(user_id, MAXLINE, stdin) == NULL) {
perror("fgets");
exit(1);
}
if(fgets(password, MAXLINE, stdin) == NULL) {
perror("fgets");
exit(1);
}
// TODO: Error checking
int fd[2], status, r, exit_status;
if (pipe(fd) == -1) {
perror("pipe");
exit(1);
}
// fork
r = fork();
if (r < 0) {
perror("fork");
}
// Child process
if (r == 0) {
// Read from the pipe
dup2(fd[0], fileno(stdin));
char user[MAXLINE];
char pswd[MAXLINE];
read(fd[0], user, MAXLINE);
read(fd[0], pswd, MAXLINE);
// Close the read end of the pipe
close(fd[0]);
dup2(fd[1], fileno(stdout));
execl("./validate", "validate", user, pswd, NULL);
close(fd[1]);
perror("execl");
exit(-1);
} else if (r > 0) {
// Parent process
// Write to the pipe
dup2(fd[1], fileno(stdout));
write(fd[1], user_id, strlen(user_id) + 1);
write(fd[1], password, strlen(password) + 1);
close(fd[1]);
wait(&status);
if (WIFEXITED(status)) {
exit_status = WEXITSTATUS(status);
if (exit_status == 0) {
printf(SUCCESS);
} else if (exit_status == 2) {
printf(INVALID);
} else if (exit_status == 3) {
printf(NO_USER);
} else {
fprintf(stderr, "Invalid exit status %d\n", exit_status);
exit(EXIT_FAILURE);
}
}
}
return 0;
}
| null | null |
63c647ab5f004bf4898cf5a9 | 2023-03-12T17:01:31.733Z | Help Fix Code | v2 | This code is meant to tokenize a word off spaces and build a list of rules and dependencies. Currently, it only does one iteration | char *dep = strtok(NULL, " ");
Rule *rule_adder = curr;
Dependency *curr_dep;
while (dep != NULL) {
// Allocate space for the dependency
Dependency *new_dep = malloc(sizeof(Dependency));
if (rule_adder->dependencies == NULL) {
rule_adder->dependencies = new_dep;
curr_dep = rule_adder->dependencies;
} else {
curr_dep->next_dep = new_dep;
curr_dep = curr_dep->next_dep;
}
// Create the corresponding Rule
curr_dep->rule = malloc(sizeof(Rule));
curr_dep->rule->target = malloc(strlen(dep) + 1);
strncpy(curr_dep->rule->target, dep, strlen(dep));
// Initialize all other fields to NULL
curr_dep->rule->actions = NULL;
curr_dep->rule->dependencies = NULL;
curr_dep->rule->next_rule = NULL;
// Add the rule to the chain
rule_adder->next_rule = curr_dep->rule;
rule_adder = rule_adder->next_rule;
dep = strtok(NULL, " ");
curr_dep->next_dep = NULL;
} | null | null |
63c647ac5f004bf4898cf5b3 | 2023-01-25T08:32:19.203Z | Explain Code | v1 | null | #include <stdlib.h>
#include <stdio.h>
/*
* Define a function void fib(...) below. This function takes parameter n
* and generates the first n values in the Fibonacci sequence. Recall that this
* sequence is defined as:
* 0, 1, 1, 2, 3, 5, ... , fib[n] = fib[n-2] + fib[n-1], ...
* The values should be stored in a dynamically-allocated array composed of
* exactly the correct number of integers. The values should be returned
* through a pointer parameter passed in as the first argument.
*
* See the main function for an example call to fib.
* Pay attention to the expected type of fib's parameters.
*/
/* Write your solution here */
void fib(int **pt_fib, int n){
*pt_fib = malloc(n * sizeof(int));
*pt_fib[0] = 0;
//*pt_fib[1] = 1;
//**(pt_fib + 1) = 1;
//printf("%d\n",*pt_fib[0]);
}
int main(int argc, char **argv) {
/* do not change this main function */
int count = strtol(argv[1], NULL, 10);
int *fib_sequence;
fib(&fib_sequence, count);
for (int i = 0; i < count; i++) {
printf("%d ", fib_sequence[i]);
}
free(fib_sequence);
return 0;
}
| null | null |
63c647ac5f004bf4898cf5b3 | 2023-01-25T08:34:05.905Z | Help Fix Code | v1 | null | #include <stdlib.h>
#include <stdio.h>
/*
* Define a function void fib(...) below. This function takes parameter n
* and generates the first n values in the Fibonacci sequence. Recall that this
* sequence is defined as:
* 0, 1, 1, 2, 3, 5, ... , fib[n] = fib[n-2] + fib[n-1], ...
* The values should be stored in a dynamically-allocated array composed of
* exactly the correct number of integers. The values should be returned
* through a pointer parameter passed in as the first argument.
*
* See the main function for an example call to fib.
* Pay attention to the expected type of fib's parameters.
*/
/* Write your solution here */
void fib(int **pt_fib, int n){
*pt_fib = malloc(n * sizeof(int));
*pt_fib[0] = 0;
*pt_fib[1] = 1;
//**(pt_fib + 1) = 1;
//printf("%d\n",*pt_fib[0]);
}
int main(int argc, char **argv) {
/* do not change this main function */
int count = strtol(argv[1], NULL, 10);
int *fib_sequence;
fib(&fib_sequence, count);
for (int i = 0; i < count; i++) {
printf("%d ", fib_sequence[i]);
}
free(fib_sequence);
return 0;
}
| should print 1 | null |
63c647ac5f004bf4898cf5b3 | 2023-01-25T08:36:31.645Z | Help Fix Code | v1 | null | #include <stdlib.h>
#include <stdio.h>
/*
* Define a function void fib(...) below. This function takes parameter n
* and generates the first n values in the Fibonacci sequence. Recall that this
* sequence is defined as:
* 0, 1, 1, 2, 3, 5, ... , fib[n] = fib[n-2] + fib[n-1], ...
* The values should be stored in a dynamically-allocated array composed of
* exactly the correct number of integers. The values should be returned
* through a pointer parameter passed in as the first argument.
*
* See the main function for an example call to fib.
* Pay attention to the expected type of fib's parameters.
*/
/* Write your solution here */
void fib(int **pt_fib, int n){
*pt_fib = malloc(n * sizeof(int));
*pt_fib[0] = 0;
//*pt_fib[1] = 1;
**(pt_fib + 1) = 1;
//printf("%d\n",*pt_fib[0]);
}
int main(int argc, char **argv) {
/* do not change this main function */
int count = strtol(argv[1], NULL, 10);
int *fib_sequence;
fib(&fib_sequence, count);
for (int i = 0; i < count; i++) {
printf("%d ", fib_sequence[i]);
}
free(fib_sequence);
return 0;
}
| should print 1 | null |
63c647ac5f004bf4898cf5b3 | 2023-01-25T09:52:28.387Z | General Question | v1 | *pt[2] is equal to what expression in C
| null | null | null |
63c647ac5f004bf4898cf5b3 | 2023-01-25T09:53:30.887Z | General Question | v1 | why *pt[2] = malloc(2 * size(int)) is invalid expression in C | null | null | null |
63c647ac5f004bf4898cf5b3 | 2023-01-25T09:58:14.403Z | Explain Code | v1 | null | int **split_array(const int *s, int length) {
int **pt;
*pt = malloc(2 * sizeof(int *));
**pt = malloc((length / 2 ) * sizeof(int));
} | null | null |
63c647ac5f004bf4898cf5b3 | 2023-01-25T10:01:53.860Z | Explain Code | v1 | null | int **split_array(const int *s, int length) {
int **pt;
*pt = malloc(2 * sizeof(int *));
pt = malloc((length / 2 ) * sizeof(int));
} | null | null |
63c647ac5f004bf4898cf5b3 | 2023-01-25T10:03:23.261Z | Help Fix Code | v1 | null | int **split_array(const int *s, int length) {
int **pt;
*pt = malloc(2 * sizeof(int *));
pt = malloc((length / 2 ) * sizeof(int));
} | Check whether the pt has structure pt[2][length / 2] | null |
63c647ac5f004bf4898cf5b3 | 2023-01-26T08:33:29.676Z | Help Fix Code | v1 | null | (define (n-of n v) void)
(if (zero? n)
`()
(cons(x xl) (n-of n-1 v))) | why my racket program saying n unbound error | null |
63c647ac5f004bf4898cf5b3 | 2023-01-26T15:09:32.147Z | General Question | v1 | How to implement greedy algorithm | null | null | null |
63c647ac5f004bf4898cf5b3 | 2023-01-26T15:10:06.571Z | General Question | v1 | You only know C? | null | null | null |
63c647ac5f004bf4898cf5b3 | 2023-02-07T15:20:59.665Z | General Question | v1 | What is write in memory when run int I=5; | null | null | null |
63c647ac5f004bf4898cf5b8 | 2023-01-23T03:07:45.045Z | General Question | v1 | how do I read in la -l input to my files without using pipes
| null | null | null |
63c647ad5f004bf4898cf5bd | 2023-01-18T00:25:10.526Z | General Question | v1 | How do I prevent segfaults? | null | null | null |
63c647ad5f004bf4898cf5bd | 2023-01-18T00:27:53.981Z | Explain Code | v1 | null | int main(int b,char**i){long long n=B,a=I^n,r=(a/b&a)>>4,y=atoi(*++i),_=(((a^n/b)*(y>>T)|y>>S)&r)|(a^r);printf("%.8s\n",(char*)&_);} | null | null |
63c647ad5f004bf4898cf5c2 | 2023-01-26T02:23:34.400Z | Explain Code | v1 | null | int arr[10]; | null | null |
63c647ad5f004bf4898cf5c2 | 2023-01-26T02:28:22.181Z | Explain Code | v1 | null | int arr[]; | null | null |
63c647ad5f004bf4898cf5c2 | 2023-01-26T02:28:51.444Z | Question from Code | v1 | How much memory is allocated? | int arr[]; | null | null |
63c647ad5f004bf4898cf5c2 | 2023-02-17T15:45:36.180Z | Explain Code | v1 | null |
#include<stdlib.h>
#include<stdio.h>
#include<string.h>
struct user{
int age1;
int *age2;
int data1[10];
int *data2;
char *name1; // string literal
char *name2; // dynamicallay allocated string
char name3[10]; // allocated when user is declared
};
void function(struct user user){
user.age1 += 1;
*user.age2 += 1;
user.data1[0] = 5;
user.data2[0] = 5;
}
int main(){
struct user user;
user.age1 = 10;
user.age2 = malloc(sizeof(int));
*user.age2 = 10;
user.data2 = malloc(sizeof(int) * 10);
for (int i = 1; i <= 10; i++){
user.data1[i - 1] = i;
user.data2[i - 1] = i;
}
user.name1 = "kai";
user.name2 = malloc(sizeof(char) * 10);
strncpy(user.name2, "kai", 10);
user.name2[9] = '\0';
strncpy(user.name3, "kai", sizeof(user.name3));
user.name3[9] = '\0';
function(user);
printf("age1: %d *age2: %d\n", user.age1, *user.age2);
printf("data1: ");
for (int i = 0; i < 10; i++){
printf("%d ", user.data1[i]);
}
printf("\n");
printf("data2: ");
for (int i = 0; i < 10; i++){
printf("%d ", user.data2[i]);
}
printf("\n")
printf("name1: %s name2: %s name3: %s", user.name1, user.name2, user.name3);
return 0;
} | null | null |
63c647ad5f004bf4898cf5c2 | 2023-04-04T16:28:24.397Z | Help Fix Code | v2 | remove target_client from the linked list, client | /*
* Remove target_client from the given clients and free the memory.
* Return the fd of the client if it was removed successfully.
* Return 0 otherwise.
*/
int remove_client(Client *target_client, Client **clients){
Client *curr_client = *clients;
// return 0 if the list is empty
if (curr_client == NULL){
return 0;
}
// find and remove target_client from the list, if it exists
if (curr_client == target_client){
*clients = curr_client->next_client;
}
else{
// find client with next client equal to the target_client
while (curr_client->next_client != NULL && curr_client->next_client != target_client){
curr_client = curr_client->next_client;
}
// return 0 if target_client doesn't exist in the list
if (curr_client->next_client == NULL){
return 0;
}
// remove the target_client
curr_client->next_client = curr_client->next_client->next_client;
}
// free the memory and return the fd
int client_fd = target_client->fd;
free(target_client->username);
free(target_client);
return client_fd;
} | null | null |
63c647ad5f004bf4898cf5c2 | 2023-04-04T16:51:56.384Z | General Question | v2 | how can i find length of int as a string
| null | null | null |
63c647ad5f004bf4898cf5c2 | 2023-04-04T18:31:34.130Z | General Question | v2 | How do i use asprintf | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-02-13T00:40:00.300Z | General Question | v1 | I've used malloc to allocate the memory in the heap for a local-scope variable, but that still gets destroyed after the function call. What went wrong? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-02-13T00:43:41.725Z | Help Fix Code | v1 | null | int make_friends (const char *name1, const char *name2, User *head) {
/* Find the users from the user list first, regardless of whether
they are valid users or not*/
User *user1 = find_user(name1, head);
User *user2 = find_user(name2, head);
// To count for existing friends a user has (To be later)
int count = 1;
// ====================== Checking assumptions ========================
// If one of them is not even a user
if (user1 == NULL || user2 == NULL) {
return 4;
} // Now both the users beyond this point are valid
// If they are the same user
if (strcmp(name1, name2) == 0) {
return 3;
}
// Count for how many friends in each user's friendlist
if (*user1->friends) {
printf("There is at least one friend for the first user\n");
User *currfriend = *user1->friends;
while (currfriend->next) {
count++;
currfriend = currfriend->next;
}
if (count == MAX_FRIENDS) {
return 2;
}
}
if (*user2->friends) {
printf("There is at least one friend for the second user\n");
// Reset
count = 1;
User *currfriend = *user2->friends;
while (currfriend->next) {
printf("%10s\n", currfriend->name);
count++;
currfriend = currfriend->next;
}
if (count == MAX_FRIENDS) {
return 2;
}
}
/* If both of them are already friends.
Note that friendship is symmetric, so checking one is good enough*/
User *first_currfriend = *user1->friends;
User *second_currfriend = *user2->friends;
// If the name is NULL <=> that user does NOT exist
while (second_currfriend->name != NULL) {
if (strcmp(second_currfriend->name, name1) == 0) {
return 1;
}
second_currfriend = second_currfriend->next;
}
// ======================== Making friendships =============================
// Loop till the end of each non-empty friendlists
/* User *copy1 = malloc(sizeof(User));
User *copy2 = malloc(sizeof(User));
User user_copy1 = *user1;
User user_copy2 = *user2;
copy1 = &user_copy1;
copy2 = &user_copy2;
copy1->next = NULL;
copy2->next = NULL; */
if (first_currfriend) {
while (first_currfriend->name) {
if (strcmp(first_currfriend->name, name2) == 0) {
return 1;
}
first_currfriend = first_currfriend->next;
}
// At the end of the friend list for first user
first_currfriend->next = user2;
}
if (second_currfriend) {
while (second_currfriend->name != NULL) {
if (strcmp(second_currfriend->name, name1) == 0) {
return 1;
}
second_currfriend = second_currfriend->next;
}
// At the end of the friend list for second user
second_currfriend->next = user1;
}
printf("\n");
// Now is the case when the first or the second user does not have a friend yet
if (!*(user1->friends)) {
// Here the first user does not have any friend
printf("There is not even a friend for user1\n");
*(user1->friends) = user2;
}
if (!*(user2->friends)) {
// Here the second user does not have any friend
printf("There is not even a friend for user2\n");
*(user2->friends) = user1;
}
return 0;
}
| Having copy1 and copy2 lasted after the function call to make_friends() | null |
63c647ae5f004bf4898cf5c7 | 2023-02-13T00:45:47.705Z | Help Fix Code | v1 | null | int make_friends (const char *name1, const char *name2, User *head) {
/* Find the users from the user list first, regardless of whether
they are valid users or not*/
User *user1 = find_user(name1, head);
User *user2 = find_user(name2, head);
// To count for existing friends a user has (To be later)
int count = 1;
// ====================== Checking assumptions ========================
// If one of them is not even a user
if (user1 == NULL || user2 == NULL) {
return 4;
} // Now both the users beyond this point are valid
// If they are the same user
if (strcmp(name1, name2) == 0) {
return 3;
}
// Count for how many friends in each user's friendlist
if (*user1->friends) {
printf("There is at least one friend for the first user\n");
User *currfriend = *user1->friends;
while (currfriend->next) {
count++;
currfriend = currfriend->next;
}
if (count == MAX_FRIENDS) {
return 2;
}
}
if (*user2->friends) {
printf("There is at least one friend for the second user\n");
// Reset
count = 1;
User *currfriend = *user2->friends;
while (currfriend->next) {
printf("%10s\n", currfriend->name);
count++;
currfriend = currfriend->next;
}
if (count == MAX_FRIENDS) {
return 2;
}
}
/* If both of them are already friends.
Note that friendship is symmetric, so checking one is good enough*/
User *first_currfriend = *user1->friends;
User *second_currfriend = *user2->friends;
// If the name is NULL <=> that user does NOT exist
while (second_currfriend->name != NULL) {
if (strcmp(second_currfriend->name, name1) == 0) {
return 1;
}
second_currfriend = second_currfriend->next;
}
// ======================== Making friendships =============================
// Loop till the end of each non-empty friendlists
User *copy1 = malloc(sizeof(User));
User *copy2 = malloc(sizeof(User));
User user_copy1 = *user1;
User user_copy2 = *user2;
copy1 = &user_copy1;
copy2 = &user_copy2;
copy1->next = NULL;
copy2->next = NULL;
if (first_currfriend) {
while (first_currfriend->name) {
if (strcmp(first_currfriend->name, name2) == 0) {
return 1;
}
first_currfriend = first_currfriend->next;
}
// At the end of the friend list for first user
first_currfriend->next = user2;
}
if (second_currfriend) {
while (second_currfriend->name != NULL) {
if (strcmp(second_currfriend->name, name1) == 0) {
return 1;
}
second_currfriend = second_currfriend->next;
}
// At the end of the friend list for second user
second_currfriend->next = user1;
}
printf("\n");
// Now is the case when the first or the second user does not have a friend yet
if (!*(user1->friends)) {
// Here the first user does not have any friend
printf("There is not even a friend for user1\n");
*(user1->friends) = user2;
}
if (!*(user2->friends)) {
// Here the second user does not have any friend
printf("There is not even a friend for user2\n");
*(user2->friends) = user1;
}
return 0;
}
| Having copy1 and copy2 stored in the heap and lasted after the function call to make_friends() | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T01:50:22.911Z | Explain Code | v2 | null | int on = 1;
int status = setsockopt(soc, SOL_SOCKET, SO_REUSEADDR, (const char *)&on, sizeof(on));
if (status < 0) {
perror("setsockopt");
exit(1);
} | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T01:52:19.215Z | Explain Code | v2 | null | if (bind(soc, (struct sockaddr *)self, sizeof(*self)) < 0) {
// bind failed; could be because port is in use.
perror("bind");
exit(1);
} | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T02:29:00.746Z | Explain Code | v2 | null | int accept_connection(int listenfd) {
struct sockaddr_in peer;
unsigned int peer_len = sizeof(peer);
peer.sin_family = AF_INET;
fprintf(stderr, "Waiting for a new connection...\n");
int client_socket = accept(listenfd, (struct sockaddr *)&peer, &peer_len);
if (client_socket < 0) {
perror("accept");
return -1;
} else {
fprintf(stderr, "New connection accepted from %s:%d\n", inet_ntoa(peer.sin_addr), ntohs(peer.sin_port));
return client_socket;
}
} | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T02:35:37.657Z | Explain Code | v2 | null | struct sockaddr_in addr;
// Allow sockets across machines.
addr.sin_family = AF_INET;
// The port the server will be listening on.
addr.sin_port = htons(port);
// Clear this field; sin_zero is used for padding for the struct.
memset(&(addr.sin_zero), 0, 8);
// Lookup host IP address.
struct hostent *hp = gethostbyname(hostname);
if (hp == NULL) {
fprintf(stderr, "unknown host %s\n", hostname);
exit(1);
}
addr.sin_addr = *((struct in_addr *)hp->h_addr); | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T02:45:35.158Z | Question from Code | v2 | Accepted connection should be printed on line 181 | int client_fd = accept(fd, NULL, NULL);
if (client_fd < 0) {
perror("server: accept");
close(fd);
exit(1);
}
// If this is a valid user
users[user_index].sock_fd = client_fd;
users[user_index].username = NULL; | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T03:13:35.912Z | Explain Code | v2 | null | char *string;
char array1[5] = "Hola";
strncpy(string, array1, 5); | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T03:14:30.127Z | Help Fix Code | v2 | string should also be "Hola" | char *string;
char array1[5] = "Hola";
strncpy(string, array1, 5); | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T03:16:00.601Z | Help Fix Code | v2 | string should be "Hola" | char *string = malloc(5);
char array1[5] = "Hola";
strncpy(string, array1, 5); | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T03:30:27.812Z | Explain Code | v2 | null | setbuf(stdout, NULL); | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T03:56:44.919Z | Question from Code | v2 | What does socket() return upon success? | int server_soc = socket(AF_INET, SOCK_STREAM, 0);
if (server_soc < 0) {
perror("Socket:");
} | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T16:11:07.300Z | General Question | v2 | Should I use select() for clients? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T16:17:14.906Z | General Question | v2 | Should I use select() on client program? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T16:31:40.766Z | General Question | v2 | Does 'return 0;' be read as 0 bytes for read()? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T16:35:58.996Z | General Question | v2 | what does FDSET() do? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T16:40:49.371Z | General Question | v2 | Could I write nothing to write()? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T16:43:39.092Z | General Question | v2 | Should I specify the size of an array first before using asprintf? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T16:45:47.065Z | General Question | v2 | When should I clean up an array of char? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T17:47:49.168Z | General Question | v2 | When should I use accept() when using select()? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T17:49:34.748Z | General Question | v2 | Can a server manage multiple connections by calling 1 accept()? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T17:51:50.260Z | General Question | v2 | How to check which fd is ready to read with FD_ISSET()? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T17:53:49.339Z | General Question | v2 | How can FD_ISSET() tell which client fd is ready? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T17:59:02.457Z | General Question | v2 | What does inet_pton() do?
| null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T18:02:35.732Z | General Question | v2 | What does FD_SET() do? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T18:07:25.796Z | General Question | v2 | What does select() return? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T18:10:28.411Z | General Question | v2 | how to tell which fd is ready to read after using select()? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T18:21:35.438Z | General Question | v2 | What members are in struct sockaddr_in? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T18:28:15.162Z | General Question | v2 | What does connect() do to client socket fd? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T18:29:57.656Z | General Question | v2 | How do I know server socket fd via connect()? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-30T19:16:35.928Z | General Question | v2 | How does connect() work on client socket? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-31T00:44:01.763Z | General Question | v2 | Does a client know a server fd after connect()? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-31T01:30:39.086Z | Question from Code | v2 | Why dereference a null pointer on line 31? | int create_user(const char *name, User **user_ptr_add) {
if (strlen(name) >= MAX_NAME) {
return 2;
}
User *new_user = malloc(sizeof(User));
if (new_user == NULL) {
perror("malloc");
exit(1);
}
strncpy(new_user->name, name, MAX_NAME); // name has max length MAX_NAME - 1
for (int i = 0; i < MAX_NAME; i++) {
new_user->profile_pic[i] = '\0';
}
new_user->first_post = NULL;
new_user->next = NULL;
for (int i = 0; i < MAX_FRIENDS; i++) {
new_user->friends[i] = NULL;
}
// Add user to list
User *prev = NULL;
User *curr = *user_ptr_add;
while (curr != NULL && strcmp(curr->name, name) != 0) {
prev = curr;
curr = curr->next;
}
if (*user_ptr_add == NULL) {
*user_ptr_add = new_user;
return 0;
} else if (curr != NULL) {
free(new_user);
return 1;
} else {
prev->next = new_user;
return 0;
}
} | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-31T01:34:58.007Z | General Question | v2 | Can I dereference a header to the null linked list in c?
| null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-31T01:49:29.877Z | General Question | v2 | Can I always modify the size of waiting queue for listen()? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-31T02:07:02.257Z | General Question | v2 | How to use execl()? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-31T02:46:33.758Z | General Question | v2 | How to run execl on one process and receive the return on the other process? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-31T03:27:31.687Z | General Question | v2 | How to use read() and write()? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-03-31T23:25:33.092Z | General Question | v2 | Is each element in argv[] separated by blank space? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-04-01T02:00:26.909Z | General Question | v2 | When does read() return 0? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-04-01T02:01:32.253Z | General Question | v2 | When does read() return 0 in socket programming? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-04-01T02:16:15.934Z | General Question | v2 | Whatt does socket() return? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-04-01T02:18:43.595Z | General Question | v2 | What does accept() take on the server side? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-04-01T02:21:33.564Z | General Question | v2 | Is accept() only be used on server side? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-04-01T02:23:10.085Z | General Question | v2 | How can a client use accept()? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-04-01T02:24:25.051Z | General Question | v2 | How does a client use connect()? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-04-01T02:27:53.874Z | General Question | v2 | Does accept() return client fd upon success? | null | null | null |
63c647ae5f004bf4898cf5c7 | 2023-04-01T02:55:30.699Z | General Question | v2 | If I malloc a whole struct, is every member of it also malloced? | null | null | null |
Subsets and Splits