I'm writing a program that parses a string and stores its values in a struct.
My problem is, when I assign the value of u->id, u->login... till u->created_at, works fine, but after I assign u->followers, u->id changes its value to " \307UUUU". The same happens after when assigning set_user_public_gists(u, p);, login changes its value from login = 0x55555555c6c0 "lorraine94588" to login = 0x55555555c6c0 "\240\307UUUU";
Why is it happening and how can i solve it?
user.c
struct user {
char *id;
char *login;
char *type;
char *created_at;
char *followers;
char *follower_list;
char *following;
char *following_list;
char *public_gists;
char *public_repos;
};
USER create_user() {
USER u = malloc(sizeof(USER));
return u;
}
void delete_user(USER u) {
free(u);
}
void set_user_id(USER u, char *s) {
u->id = strdup(s);
}
void set_user_login(USER u, char *s) {
u->login = strdup(s);
}
void set_user_type(USER u, char *s) {
u->type = strdup(s);
}
void set_user_created_at(USER u, char *s) {
u->created_at = strdup(s);
}
void set_user_followers(USER u, char *s) {
u->followers = strdup(s);
}void set_user_follower_list(USER u, char *s) {
u->follower_list = strdup(s);
}
void set_user_following(USER u, char *s) {
u->following = strdup(s);
}
void set_user_following_list(USER u, char *s) {
u->following_list = strdup(s);
}
void set_user_public_gists(USER u, char *s) {
u->public_gists = strdup(s);
}
void set_user_public_repos(USER u,char *s) {
u->public_repos = strdup(s);
}
void set_user(USER u, char *line) {
char *p = NULL, *temp_line = line;
int i = 0;
while ((p = strsep(&temp_line, ";")) != NULL) {
switch (i) {
case 0:
set_user_id(u, p);
break;
case 1:
set_user_login(u, p);
break;
case 2:
set_user_type(u, p);
break;
case 3:
set_user_created_at(u, p);
break;
case 4:
set_user_followers(u, p);
break;
case 5:
set_user_follower_list(u, p);
break;
case 6:
set_user_following(u, p);
break;
case 7:
set_user_following_list(u, p);
break;
case 8:
set_user_public_gists(u, p);
break;
case 9:
set_user_public_repos(u, p);
break;
}
i ;
}
}
GDB
79 set_user_followers(u, p);
(gdb) print u[0]
$14 = {id = 0x55555555c6a0 "6611157", login = 0x55555555c6c0 "lorraine94588", type = 0x55555555c6e0 "User",
created_at = 0x55555555c700 "2014-02-07 01:01:35",
followers = 0x37353131313636 <error: Cannot access memory at address 0x37353131313636>, follower_list = 0x0, following = 0x0,
following_list = 0x21 <error: Cannot access memory at address 0x21>,
public_gists = 0x656e696172726f6c <error: Cannot access memory at address 0x656e696172726f6c>,
public_repos = 0x3838353439 <error: Cannot access memory at address 0x3838353439>}
(gdb) n
80 break;
(gdb) print u[0]
$15 = {id = 0x55555555c6a0 " \307UUUU", login = 0x55555555c6c0 "lorraine94588", type = 0x55555555c6e0 "User",
created_at = 0x55555555c700 "2014-02-07 01:01:35", followers = 0x55555555c720 "0", follower_list = 0x0, following = 0x0,
following_list = 0x21 <error: Cannot access memory at address 0x21>,
public_gists = 0x656e696172726f6c <error: Cannot access memory at address 0x656e696172726f6c>,
public_repos = 0x3838353439 <error: Cannot access memory at address 0x3838353439>}
(gdb)
CodePudding user response:
You allocate not enough bytes (I assume that USER is a pointer).
Rather than reserving bytes for struct user
you allocate only enough bytes to handle a pointer to struct user
.
Rather than:
USER u = malloc(sizeof(USER));
it should be
USER u = malloc(sizeof *u);
Two hints for future:
- do not hide pointers behind the typedef (except function pointers)
- use the actual object in
sizeof
rather than type:
x = malloc(sizeof *x);