chdir() to home directory

I am using the chdir() C function to allow a user to change directory.

The function however, doesn't recognize '~'. Do I need to do any explicit conversion, so chdir doesn't recognize what ~ means? Because mine isn't working. Or am I doing something wrong?

What does chdir do?

chdir() changes the current working directory of the calling process to the directory specified in path.

What does chdir return?

If successful, chdir() returns a value of zero. On failure, it returns -1 and sets errno to the one of the following: EACCES.

Tilde expansion is handled by the shell, not by a system call. You could use getenv() to read the environment variable HOME and then use that as the argument to chdir().

There are system calls to get this information that may be more reliable on an individual system, but they're not completely portable. Look, for example, at getpwuid().