.\" @(#)$RCSfile: dpns_readdirxr.man,v $ $Revision: 4458 $ $Date: 2011-06-15 09:20:59 +0200 (Wed, 15 Jun 2011) $ CERN IT-GD/SC Jean-Philippe Baud
.\" Copyright (C) 2005-2011 by CERN/IT/GD/SC
.\" All rights reserved
.\"
.TH DPNS_READDIRXR 3 "$Date: 2011-06-15 09:20:59 +0200 (Wed, 15 Jun 2011) $" DPNS "DPNS Library Functions"
.SH NAME
dpns_readdirxr \- read DPNS directory opened by
.B dpns_opendir
in the name server
.SH SYNOPSIS
.B #include <sys/types.h>
.br
\fB#include "dpns_api.h"\fR
.sp
.BI "struct dpns_direnrep *dpns_readdirxr (dpns_DIR *" dirp ,
.BI "char *" se )
.SH DESCRIPTION
.B dpns_readdirxr
reads the DPNS directory opened by
.B dpns_opendir
in the name server.
This routine returns a pointer to a structure containing the current directory
entry (basename, guid and filesize) and the replica information.
.PP
.nf
.ft CW
struct dpns_rep_info {
	u_signed64	fileid;
	char		status;
	char		*host;
	char		*sfn;
};

struct dpns_direnrep {
	u_signed64	fileid;
	char		guid[CA_MAXGUIDLEN+1];
	mode_t		filemode;
	u_signed64	filesize;
	int		nbreplicas;
	struct dpns_rep_info *rep;	/* array of replica info structures */
	unsigned short	d_reclen;	/* length of this entry */
	char		d_name[1];	/* basename in variable length */
};
.ft
.fi
.PP
.B dpns_readdirxr
caches a variable number of such entries, depending on the filename size, to
minimize the number of requests to the name server.
.TP
.I dirp
specifies the pointer value returned by
.BR dpns_opendir .
.TP
.I se
allows to restrict the replica entries to a given SE.
.SH RETURN VALUE
This routine returns a pointer to a structure containing the current directory
entry if the operation was successful or NULL if the end of the directory was
reached or if the operation failed. When the end of the directory is encountered,
serrno is not changed. If the operation failed,
.B serrno
is set appropriately.

As dpns_readdirxr returns a null pointer
both at the end of the directory and on error, an application wishing to check
for error situations should set
.B serrno
to 0, then call dpns_readdirxr, then check
.B serrno
and if it is non-zero, assume an error has occurred.
.SH ERRORS
.TP 1.3i
.B EBADF
File descriptor in DIR structure is invalid.
.TP 
.B ENOMEM
Memory could not be allocated for unmarshalling the reply.
.TP
.B EFAULT
.I dirp
is a NULL pointer.
.TP
.B EINVAL
The length of
.I se
exceeds
.BR CA_MAXHOSTNAMELEN .
.TP
.B SECOMERR
Communication error.
.TP
.B ENSNACT
Name server is not running or is being shutdown.
.SH SEE ALSO
.BR dpns_closedir(3) ,
.BR dpns_opendir(3) ,
.B dpns_rewinddir(3)
.SH AUTHOR
\fBLCG Grid Deployment\fP Team