C array of pointers to strings, passing string from pointer

Question

I have an array of pointers to strings (char ** array), and I have a pointer, which points somewhere into this array (for example, third char of array[0]). I need use strncmp, where as second argument, I would pass string starting from where the pointer is.

i.e.:

char ** array = (char**) malloc (sizeof(char*)*count);

array[0] = "Hello World";
char * p = array[0] + 3; /* just for example */
strncmp(query, ?, somemagicnumber);

what '?' should contain, in this case, 'lo World' (p points to second l in Hello);

How do I do this? Is it even possible?

Thanks for your help.

I'm having a hard time understanding the question. Do you want strncmp(query, p, somemagicnumber);? — Edward
– Edward, Commented Dec 18, 2014 at 14:21
Your array[0] = "Hello World" expression is wrong, to copy the string into array[0] use strcpy(array[0], "Hello World"). Since you are doing this array[0] = malloc(n). And hence you are overwriting array[0] with another address. — Iharob Al Asimi
– Iharob Al Asimi, Commented Dec 18, 2014 at 14:22
@iharob The assignment is perfectly fine - he does not need to make a copy (although he certainly can make it if he wants to) Of course he's got a memory leak there. — Sergey Kalinichenko
– Sergey Kalinichenko, Commented Dec 18, 2014 at 14:23
@dasblinkenlight Although the malloc above becomes completely useless and the memory is leaked, suggesting its not what the author intended. But sure per definition you're right, it's certainly valid, but stupid, to do so. — Jite
– Jite, Commented Dec 18, 2014 at 14:24
@Jite Yes - he needs to either remove the second malloc, or use strcpy like iharob suggests. — Sergey Kalinichenko
– Sergey Kalinichenko, Commented Dec 18, 2014 at 14:25

Gopi · Accepted Answer · 2014-12-18 14:22:05Z

2

int strncmp(char *string1, char *string2, int n);

This is the prototype of strncmp()

In your case pass

strncmp("somestring",p,n); /* n = number of characters to be compared */

answered Dec 18, 2014 at 14:22

Gopi

19.9k4 gold badges28 silver badges37 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

C array of pointers to strings, passing string from pointer

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related