How do we check whether a string starts with a substring?

[SoFaraway]

Dear all,

In C, how do we check whether a string starts with a substring? E.g.,
char *str = ...;
char *substr = ...;

How do we check whether str starts with substr?

Thank you very much!

[scruggsy]

Dear all,

In C, how do we check whether a string starts with a substring? E.g.,
char *str = ...;
char *substr = ...;

How do we check whether str starts with substr?

Thank you very much!

Forget about doing it in C for the moment.
How would you do it, if you were looking at the two strings written side by side on a piece of paper?
Write down the steps you would take, in English, then translate it into C.
If you need help with the code, post what you have so far.

[Meetee]

Dear all,

In C, how do we check whether a string starts with a substring? E.g.,
char *str = ...;
char *substr = ...;

How do we check whether str starts with substr?

Thank you very much!

Hi,

If str = "Good Morning" and substr = "Good", you can compare substr in str until white space, and if both are same purpose is solved!

Regards

[Yaseen Rauf]

If str is your orginal string, substr is the substring you want to check, then
strncmp(str, substr, strlen(substr)) will return 0 if str starts with substr. The functions strncmp and strlen are in the C header file <string.h>