How to implement readlink to find the path

Question

Using the readlink function used as a solution to How do I find the location of the executable in C?, how would I get the path into a char array? Also, what do the variables

Answer 1

Let's look at what the manpage says:

 readlink() places the contents of the symbolic link path in the buffer
 buf, which has size bufsiz.  readlink does not append a NUL character to
 buf.

OK. Should be simple enough. Given your buffer of 1024 chars:

 char buf[1024];

 /* The manpage says it won't null terminate.  Let's zero the buffer. */
 memset(buf, 0, sizeof(buf));

 /* Note we use sizeof(buf)-1 since we may need an extra char for NUL. */
 if (readlink("/proc/self/exe", buf, sizeof(buf)-1) < 0)
 {
    /* There was an error...  Perhaps the path does not exist
     * or the buffer is not big enough.  errno has the details. */
    perror("readlink");
    return -1;
 }