open for /proc/self/psinfo:
fname: proc_psinfo
psargs: ./proc_psinfo arg1 arg 2 arg3
argc: 4
argv[0]: ./proc_psinfo
argv[1]: arg1
argv[2]: arg 2
argv[3]: arg3

open for /proc/<pid>/psinfo:
fname: proc_psinfo
psargs: ./proc_psinfo arg1 arg 2 arg3
argc: 4
argv[0]: ./proc_psinfo
argv[1]: arg1
argv[2]: arg 2
argv[3]: arg3

openat for /proc/self/psinfo:
fname: proc_psinfo
psargs: ./proc_psinfo arg1 arg 2 arg3
argc: 4
argv[0]: ./proc_psinfo
argv[1]: arg1
argv[2]: arg 2
argv[3]: arg3

openat for /proc/<pid>/psinfo:
fname: proc_psinfo
psargs: ./proc_psinfo arg1 arg 2 arg3
argc: 4
argv[0]: ./proc_psinfo
argv[1]: arg1
argv[2]: arg 2
argv[3]: arg3