FD2PATH(2) FD2PATH(2)
NAME
fd2path - return file name associated with file descriptor
SYNOPSIS
include "sys.m";
sys := load Sys Sys->PATH;
fd2path(fd: ref FD): string;
DESCRIPTION
As described in intro(2), the kernel stores a rooted path
name with every open file or directory; typically, it is the
name used in the original access of the file. Fd2path
returns the path name associated with open file descriptor
fd. (It returns nil if an error occurs.)
Changes to the underlying name space do not update the path
name stored with the file descriptor. Therefore, the path
returned by fd2path may no longer refer to the same file (or
indeed any file) after some component directory or file in
the path has been removed, renamed or rebound.
As an example, workdir(2) is implemented by opening . and
executing fd2path on the resulting file descriptor.
SEE ALSO
bind(1), ns(1), sys-bind(2), sys-intro(2), workdir(2),
prog(3)
DIAGNOSTICS
Fd2path returns nil on error and sets the system error
string.
Page 1 Plan 9 (printed 10/27/25)