HSEARCH(3C)             COMMAND REFERENCE             HSEARCH(3C)



NAME
     hsearch, hcreate, hdestroy - manage hash search tables

SYNOPSIS
     #include <search.h>

     ENTRY *hsearch (item, action)
     ENTRY item;
     ACTION action;

     int hcreate (nel)
     unsigned nel;

     void hdestroy ( )

DESCRIPTION
     Hsearch is a hash table search routine generalized from
     Knuth (6.4) Algorithm D.  It returns a pointer into a hash
     table indicating the location at which an entry can be
     found.  Item is a structure of type ENTRY (defined in the
     <search.h> header file) containing two pointers: item.key
     points to the comparison key, and item.data points to any
     other data to be associated with that key.  (Pointers to
     types other than a character should be cast to pointer-to-
     character.) Action is a member of an enumeration type ACTION
     indicating the disposition of the entry if it cannot be
     found in the table.  ENTER indicates that the item should be
     inserted in the table at an appropriate point.  FIND
     indicates that no entry should be made.  Unsuccessful
     resolution is indicated by the return of a NULL pointer.

     Hcreate allocates sufficient space for the table, and must
     be called before hsearch is used.  Nel is an estimate of the
     maximum number of entries that the table will contain.  This
     number may be adjusted upward by the algorithm in order to
     obtain certain mathematically favorable circumstances.

     Hdestroy destroys the search table, and may be followed by
     another call to hcreate.

DIAGNOSTICS
     Hsearch returns a NULL pointer if either the action is FIND
     and the item could not be found or the action is ENTER and
     the table is full.

     Hcreate returns 0 if it cannot allocate sufficient space for
     the table.

CAVEATS
     Only one hash search table may be active at any given time.





Printed 3/13/89                                                 1

HSEARCH(3C)             COMMAND REFERENCE             HSEARCH(3C)



     Hsearch uses open addressing with a multiplicative hash
     function.

SEE ALSO
     bsearch(3c), lsearch(3c), string(3c), and tsearch(3c).


















































Printed 3/13/89                                                 2

%%index%%
na:336,106;
sy:442,1335;
de:1777,1931;
di:3708,589;
ca:4297,145;4850,203;
se:5053,256;
%%index%%000000000120