Linux Certif

Toute la documentation sur la certification Linux LPI

dpns_readdirg

NAME

dpns_readdir - read DPNS directory opened by dpns_opendir in the name server

SYNOPSIS

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

struct dpns_direnstatg *dpns_readdir (dpns_DIR *dirp)

DESCRIPTION

dpns_readdir reads the DPNS directory opened by dpns_opendir in the name server. This routine returns a pointer to a structure containing the current directory entry including the GUID associated.

 struct dpns_direnstatg {
         u_signed64      fileid;
         char            guid[CA_MAXGUIDLEN+1];
         mode_t          filemode;
         int             nlink;          /* number of files in a directory */
         uid_t           uid;
         gid_t           gid;
         u_signed64      filesize;
         time_t          atime;          /* last access to file */
         time_t          mtime;          /* last file modification */
         time_t          ctime;          /* last metadata modification */
         short           fileclass;      /* not used */
         char            status;         /* ' ' --> online, 'm' --> migrated */
         char            csumtype[3];    /* "CS", "AD" or "MD" */
         char            csumvalue[33];
         unsigned short  d_reclen;       /* length of this entry */
         char            d_name[1];      /* basename in variable length */
 };
 

dpns_readdir caches a variable number of such entries, depending on the filename size, to minimize the number of requests to the name server.

dirp

specifies the pointer value returned by dpns_opendir.

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, serrno is set appropriately.

As dpns_readdir returns a null pointer both at the end of the directory and on error, an application wishing to check for error situations should set serrno to 0, then call dpns_readdir, then check serrno and if it is non-zero, assume an error has occurred.

ERRORS

EBADF

File descriptor in DIR structure is invalid.

EFAULT

dirp is a NULL pointer.

SENOSHOST

Host unknown.

SENOSSERV

Service unknown.

SECOMERR

Communication error.

ENSNACT

Name server is not running or is being shutdown.

SEE ALSO

dpns_closedir(3), dpns_opendir(3), dpns_rewinddir(3)

AUTHOR

LCG Grid Deployment Team