NAME¶

rfio_symlink - create a symbolic link to a file

SYNOPSIS¶

#include <sys/types.h>
#include "rfio_api.h"

int rfio_symlink (const char *oldpath, const char *newpath);
int rfio_msymlink (const char *oldpath, const char *newpath);
int rfio_msymlink_reset ();
int rfio_symend ();

DESCRIPTION¶

rfio_symlink creates a symbolic link newpath which contains the string oldpath.

newpath may point to a non existing file.
If newpath exists already, it will not be overwritten.
Write permission is required on newpath parent.

rfio_msymlink is identical to rfio_symlink but keeps the connection open to the server unless there are more than MAXMCON connections already opened. This is useful when issuing a series of symlink calls. The last rfio_msymlink call should be followed by a call to rfio_symend.

rfio_msymlink_reset is to be used when your program is forking. In such a case the permanent connections opened with rfio_msymlink become shared between the parent and the child. Use rfio_msymlink_reset to perform the necessary reset and close of the socket file descriptor in the parent or the child in order to be sure that only of them will receice an answer from the RFIO daemon.

See NOTES section below.

RETURN VALUE¶

This routine returns 0 if the operation was successful or -1 if the operation failed. In the latter case, serrno is set appropriately.

NOTES¶

Multiple connections using rfio_msymlink are thread-safe but not process-wide, therefore a forked child can share file descriptors opened with rfio_msymlink by its parent. Use rfio_msymlink_reset in such case.

Multiple connections behaviour is undefined if you work in a multi-threaded environment and with threads not created using the LCG's Cthread interface.

ERRORS¶

ENOENT

A component of newpath prefix does not exist or oldpath is a null pathname.

ENOMEM

Insufficient memory.

EACCES

Search permission is denied on a component of the newpath prefix or write permission on the newpath parent directory is denied.

EFAULT

oldpath or newpath is a NULL pointer.

EEXIST

newpath already exists.

ENOTDIR

A component of the newpath prefix is not a directory.

ENAMETOOLONG

The length of oldpath or newpath exceeds CA_MAXPATHLEN or the length of a path component exceeds CA_MAXNAMELEN.

SENOSHOST

Host unknown.

SENOSSERV

Service unknown.

SECOMERR

Communication error.

SEOPNOTSUP

Not supported on Windows.

SEE ALSO¶

Castor_limits(4), rfio_readlink(3), rfio_unlink(3), Cthread(3)

AUTHOR¶

LCG Grid Deployment Team