#include <stdlib.h>
#include <limits.h>
#include <stdio.h>

int main() {
    const char *execname;
    char *execpath;
    char pathbuf[PATH_MAX];
    
    execname = getexecname();
    execpath = realpath(execname, pathbuf);
    printf("execname: %s\n", execname);
    printf("realpath: %s\n", execpath);
}

##</code><code>##

 
$ ./bar
execname: bar
realpath: /home/ck/myscripts/bar

##</code><code>##

$ ./bar
execname: /home/ck/bin/foo
realpath: /home/ck/bin/foo