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 feature(PCI)                   6 January 1993                   feature(PCI)


 Name

    feature, feature_exists, feature_list - get features supported by a
    virtual drive

 Syntax


    #include <pcilib.h>


    #include <memmdl.h>

    char *feature_list(drive)
    int drive;

    char *feature(drive, token)
    int drive;
    char *token;

    int *feature_exists(drive, token, version)
    int drive;
    char *token, *version;


 Description

    featurelist() returns a pointer to a null-terminated string containing
    feature version information of the form:

       "token=version[,token=version...]"

    For example, the feature list could appear as:

       "F=1,PCI=3.2.0,LCSTBL=8859"

    feature() calls featurelist() as a subroutine, and returns a pointer to
    a null-terminated version string corresponding to a ``token=version''
    pair in the string returned by featurelist().

    featureexists() calls feature() as a subroutine and returns 1 if the
    specified token is paired with the specified version in the string
    returned by feature(); otherwise, it returns 0.  If called with version
    set to NULL, featureexists() returns 1 if the specified token exists at
    all in the string returned by featurelist().

    drive is the drive number of the host whose feature list is being
    requested.  Drive letters and numbers correspond in the following way:
    A:= 1, B:= 2, and so forth.  A value of 0 indicates the local bridge.

    In  Version 3.2 or greater, the LCSTBL feature is present and returns the
    UNIX operating system code set associated with the virtual drive.  The
    feature PCI or MERGE returns the  or Merge version number of the local
    bridge.  This can also be used to determine if an application is running
    under  or Merge.  Any other features not documented here are for internal
    use only.

 Diagnostics

    If the server specified does not support feature-version list swapping,
    featurelist() returns a pointer to a null string ("").  If the drive
    specified does not refer to the local bridge device or a connected remote
    server, or if the local bridge does not support feature-version list
    swapping, featurelist() returns NULL.

    If the token specified cannot be found in the string returned by fea-
    turelist(), or if featurelist() returns NULL for the drive specified,
    feature() returns NULL.

    If feature() returns NULL for the drive and token specified, fea-
    tureexists() returns 0.

 Warning

    The return values of feature() and featurelist() point to internal data
    areas that should not be corrupted.  Furthermore, these pointers should
    not be relied upon after subsequent calls to any of these routines.

 Example

    Using the sample program below, the following queries on a virtual drive
    connected to a system running  2.1 virtual drive connected to a system
    running  3.1 would display the responses shown:

    Query:          feature d: PCI
    Response:       Feature PCI is 3.2.0

    Query:          feature d:
    Response:       Feature list of D: is F=1,PCI=3.2.0,LCSTBL=8859

    Query:          feature 0 MERGE
    Response:       Feature MERGE does not exist

    Query:          feature 0 PCI 3.2.0
    Response:       Feature PCI=3.2.0 exists


       Source code:
       #include <stdio.h>
       #include <ctype.h>
       #include <pcilib.h>

       main(argc, argv)
       int argc;
       char **argv;
       {
               char *res;
               int ires;
               int host;
               char *token;
               char *vers;

               if (argc < 2) {
                       printf("usage: feature host [token [vers]]\n");
                       exit(1);
               }
               host = 0;
               token = NULL;
               vers = NULL;
               argv++;
               if (isdigit(**argv))
                       sscanf(*argv, "%d", &host);
               else
                       host = tolower(**argv) - 'a' + 1;
               if (argc >= 3)
                       token = *++argv;
               if (argc >= 4) {
                       vers = *++argv;
                       ires = feature_exists(host, token, vers);
                       printf("Feature %s=%s %s\n", token, vers,
                               ires ? "exists" : "does not exist");
                       exit(0);
               }
               if (argc == 3) {
                       res = feature(host, token);
                       if (res != NULL)
                               printf("Feature %s is %s\n", token, res);
                       else
                               printf("Feature %s does not exist\n", token);
               } else {
                       res = feature_list(host);
                       if (res != NULL)
                               printf("Feature list of %c: is %s\n", host+'@', res);
                       else
                               printf("Feature list does not exist on %c\n", host+'@');
               }
       }