ph_query(3) C Library Calls ph_query(3)NAME
ph_query, ph_free_entries, ph_free_query - retrieve data from a PH
server
SYNOPSIS
#include <phclient.h>
int ph_query(PH *ph, struct ph_fieldselector query[], char *ret‐
fields[], ph_entry **entries);
int ph_free_entries(ph_entry *entries);
VERSION
This man page documents version 1.2 of libphclient.
DESCRIPTION
The ph_query() function retrieves entries from the PH server associated
with the PH handle ph. The query argument selects which entries to
return. The retfields argument indicates which fields from the
selected entries should be returned. The resulting entries are stored
in dynamicly-allocated memory, and the entries argument is set to point
to them.
The query argument is an array of structures which contain the follow‐
ing fields: field (a string representation of the field name), value (a
string representation of the value to check for), and operation (a
character value indicating how the field and value should be compared).
If field is NULL, the operation field is ignored and the value is
matched against the default fields on the server. The only univer‐
sally-supported value for operation is '=', but other possibilities
include '~', '<', and '>'.
The retfields argument is a NULL-terminated array of strings which
lists the fields to return. If retfields is NULL, the default set of
fields is returned from the server.
The ph_free_entries() function is used to free memory allocated by
ph_query() for the entries argument.
RETURN VALUE
On success, the ph_query() function returns the number of entries which
matched query. If the query matched too many entries for the server to
return them, it returns PH_ERR_TOOMANY. If no entries matched, it
returns PH_ERR_NOMATCH. If the query was invalid, it returns
PH_ERR_DATAERR. On error, it returns -1 and sets errno.
ERRORS
The ph_query() function will fail with EINVAL if it receives an unex‐
pected response code from the server. In addition, it may fail with
any error from the functions read() or write().
SEE ALSOread(2), write(2), ph_open(3)University of Illinois Oct 2002 ph_query(3)
