MirBSD manpage: realpath(3)

REALPATH(3)                BSD Programmer's Manual                 REALPATH(3)

NAME

     realpath - returns the canonicalized absolute pathname

SYNOPSIS

     #include <sys/param.h>
     #include <stdlib.h>

     char *
     realpath(const char *pathname, char resolved[PATH_MAX]);

DESCRIPTION

     The realpath() function resolves all symbolic links, extra "/" characters
     and references to /./ and /../ in pathname, and copies the resulting ab-
     solute pathname into the memory referenced by resolved. The resolved ar-
     gument must refer to a buffer capable of storing at least PATH_MAX char-
     acters.

     The realpath() function will resolve both absolute and relative paths and
     return the absolute pathname corresponding to pathname. All but the last
     component of pathname must exist when realpath() is called.

RETURN VALUES

     The realpath() function returns resolved on success. If an error occurs,
     realpath() returns NULL and the contents of resolved are undefined.

ERRORS

     The function realpath() may fail and set the external variable errno for
     any of the errors specified for the library functions lstat(2),
     readlink(2), and getcwd(3).

SEE ALSO

     readlink(1), getcwd(3)

HISTORY

     The realpath() function call first appeared in 4.4BSD.

     Up to and including IEEE Std 1003.1-2001 ("POSIX.1"), the resolved argu-
     ment must point to a large enough buffer; IEEE Std 1003.1-2008 ("PO-
     SIX.1") changed this to also allow passing NULL, causing the function to
     allocate sufficient space itself, which the caller must later free(3).
     This is supported as of MirBSD #11.

CAVEATS

     This implementation of realpath() differs slightly from the Solaris im-
     plementation. The 4.4BSD version always returns absolute pathnames,
     whereas the Solaris implementation will, under certain circumstances, re-
     turn a relative resolved when given a relative pathname.

MirBSD #10-current             August 25, 2019                               1