When stdio in C, IO functions are preceeded by f (e.g. fopen, fprintf, fputs and fgetc) to avoid confusion and conflicts with system calls and non-file version.

That's not the case in Perl. Perl labels the system calls instead (e.g. sysopen and syswrite) instead of the high-level call, since they the system calls are not used as often. To differentiate between file and non-file version, Perl uses polymorphism (e.g. print ... vs print FILE ..., printf ... vs printf FILE ...).