```{index} single: fpathconf; POSIX function ``` ```{index} single: POSIX::fpathconf; Perl function ``` # fpathconf Runtime limit for a configuration variable on an open fd. ## Synopsis ```perl use POSIX qw(fpathconf _PC_NAME_MAX); my $max = fpathconf($fd, _PC_NAME_MAX); ``` ## What you get back The limit value, or `-1` if the variable is unsupported or unlimited (check `$!` to distinguish). ## Differences from upstream Fully compatible with upstream POSIX.