isindexinfo(S)                 6 January 1993                 isindexinfo(S)


 Name

    isindexinfo - obtain information about an ISAM file

 Syntax


    cc  . . .  -lisam


    isindexinfo (isfd, buffer, number)
    int isfd;
    struct { keydesc | dictinfo } *buffer;
    int number;


 Description

    The information returned by the isindexinfo call can be either dictionary
    information or index information, depending on the number parameter.  You
    can use the following arguments with this routine:


    _________________________________________________________________________
    Argument                         Description
    _________________________________________________________________________
    isfd                             File descriptor identifying the ISAM
                                     file for which information is to be
                                     obtained.
    buffer                           Name of the buffer with structure key-
                                     desc or dictinfo into which the informa-
                                     tion is placed.
    keydesc                          Structure defined in isam.h to hold
                                     index information.  Use only if number
                                     is nonzero.
    dictinfo                         Structure defined in isam.h to hold file
                                     dictionary information.  Use only if
                                     number is zero.
    number                           Non-negative integer determining what
                                     information is obtained.  If zero, then
                                     the file's dictionary information is put
                                     into the buffer.  Otherwise, information
                                     about the index with that number is put
                                     into the buffer.

    Dictionary information about a file includes the number of indexes
    defined, the record size, the primary index size, and the number of
    records in the file.  Dictionary information is placed in the buffer by
    the call when the number parameter is set to zero.  The buffer should use
    the dictinfo structure defined in isam.h as:

       struct dictinfo {
               short di_nkeys ;          /* number of keys defined */
               short di_recsize ;        /* data record size */
               short di_idxsize ;        /* index key size */
               long di_nrecords ;        /* number of records in file */
       };

    Index information includes flags (duplicates, compression), number of
    parts in the key, and the length, type, and location of each key part.
    Index information is placed in the buffer by the call when the number
    parameter is set to the number of the index.  The buffer should use the
    keydesc structure defined in isam.h as:

       struct keypart {
               short kp_start ;              /* starting byte of key part */
               short kp_leng ;               /* length in bytes */
               short kp_type ;               /* type of key part */
       };

       struct keydesc {
               short k_flags ;               /* flags */
               short k_nparts ;              /* number of parts in key */
               struct keypart k_part[NPARTS] ;        /* each key part */
       };

    The number of an index can change when indexes are added or deleted. Use
    the information in dictinfo about the number of indexes to check all
    indexes.

    On success, isindexinfo returns 0.  Otherwise, it returns -1 and sets
    iserrno to indicate the error.

 Example

    This example obtains information about the ISAM file:

       struct dictinfo dictbuffer
       isindexinfo(bookfd, dictbuffer, 0) ;

    This example obtains information about the second index:

       struct keydesc keybuffer
       isindexinfo(bookfd, keybuffer, 2) ;


 See also

    isaddindex(S), isbuild(S)

 Standards conformance

    isindexinfo is not part of any currently supported standard; it is an
    extension of AT&T System V provided by the Santa Cruz Operation.