configfile.c

基于ntp协议的网络时间服务程序

            strcpy( pz, pOpts->pzRcName );
        }

        filePreset( pOpts, zFileName, inc );

        /*
         *  IF we are now to skip config files AND we are presetting,
         *  THEN change direction.  We must go the other way.
         */
        {
            tOptDesc * pOD = pOpts->pOptDesc + pOpts->specOptIdx.save_opts+1;
            if (DISABLED_OPT(pOD) && PRESETTING(inc)) {
                idx -= inc;  /* go back and reprocess current file */
                inc =  DIRECTION_PROCESS;
            }
        }
    } /* twice for every path in the home list, ... */
}


/*=export_func optionFileLoad
 *
 * what: Load the locatable config files, in order
 *
 * arg:  + tOptions*   + pOpts  + program options descriptor +
 * arg:  + char const* + pzProg + program name +
 *
 * ret_type:  int
 * ret_desc:  0 -> SUCCESS, -1 -> FAILURE
 *
 * doc:
 *
 * This function looks in all the specified directories for a configuration
 * file ("rc" file or "ini" file) and processes any found twice.  The first
 * time through, they are processed in reverse order (last file first).  At
 * that time, only "immediate action" configurables are processed.  For
 * example, if the last named file specifies not processing any more
 * configuration files, then no more configuration files will be processed.
 * Such an option in the @strong{first} named directory will have no effect.
 *
 * Once the immediate action configurables have been handled, then the
 * directories are handled in normal, forward order.  In that way, later
 * config files can override the settings of earlier config files.
 *
 * See the AutoOpts documentation for a thorough discussion of the
 * config file format.
 *
 * Configuration files not found or not decipherable are simply ignored.
 *
 * err:  Returns the value, "-1" if the program options descriptor
 *       is out of date or indecipherable.  Otherwise, the value "0" will
 *       always be returned.
=*/
int
optionFileLoad( tOptions* pOpts, char const* pzProgram )
{
    if (! SUCCESSFUL( validateOptionsStruct( pOpts, pzProgram )))
        return -1;

    pOpts->pzProgName = pzProgram;
    internalFileLoad( pOpts );
    return 0;
}


/*=export_func  optionLoadOpt
 * private:
 *
 * what:  Load an option rc/ini file
 * arg:   + tOptions* + pOpts    + program options descriptor +
 * arg:   + tOptDesc* + pOptDesc + the descriptor for this arg +
 *
 * doc:
 *  Processes the options found in the file named with
 *  pOptDesc->optArg.argString.
=*/
void
optionLoadOpt( tOptions* pOpts, tOptDesc* pOptDesc )
{
    /*
     *  IF the option is not being disabled, THEN load the file.  There must
     *  be a file.  (If it is being disabled, then the disablement processing
     *  already took place.  It must be done to suppress preloading of ini/rc
     *  files.)
     */
    if (! DISABLED_OPT( pOptDesc )) {
        struct stat sb;
        if (stat( pOptDesc->optArg.argString, &sb ) != 0) {
            if ((pOpts->fOptSet & OPTPROC_ERRSTOP) == 0)
                return;

            fprintf( stderr, zFSErrOptLoad, errno, strerror( errno ),
                     pOptDesc->optArg.argString );
            exit(EX_NOINPUT);
            /* NOT REACHED */
        }

        if (! S_ISREG( sb.st_mode )) {
            if ((pOpts->fOptSet & OPTPROC_ERRSTOP) == 0)
                return;

            fprintf( stderr, zNotFile, pOptDesc->optArg.argString );
            exit(EX_NOINPUT);
            /* NOT REACHED */
        }

        filePreset(pOpts, pOptDesc->optArg.argString, DIRECTION_CALLED);
    }
}


/*  parseAttributes
 *
 *  Parse the various attributes of an XML-styled config file entry
 */
LOCAL char*
parseAttributes(
    tOptions*           pOpts,
    char*               pzText,
    tOptionLoadMode*    pMode,
    tOptionValue*       pType )
{
    size_t lenLoadType = strlen( zLoadType );
    size_t lenKeyWords = strlen( zKeyWords );
    size_t lenSetMem   = strlen( zSetMembers );

    do  {
        switch (*pzText) {
        case '/': pType->valType = OPARG_TYPE_NONE;
        case '>': return pzText;

        default:
        case NUL: return NULL;

        case ' ':
        case '\t':
        case '\n':
        case '\f':
        case '\r':
        case '\v':
            break;
        }

        while (isspace( (int)*++pzText ))   ;

        if (strncmp( pzText, zLoadType, lenLoadType ) == 0) {
            pzText = parseValueType( pzText+lenLoadType, pType );
            continue;
        }

        if (strncmp( pzText, zKeyWords, lenKeyWords ) == 0) {
            pzText = parseKeyWordType( pOpts, pzText+lenKeyWords, pType );
            continue;
        }

        if (strncmp( pzText, zSetMembers, lenSetMem ) == 0) {
            pzText = parseSetMemType( pOpts, pzText+lenSetMem, pType );
            continue;
        }

        pzText = parseLoadMode( pzText, pMode );
    } while (pzText != NULL);

    return pzText;
}


/*  parseKeyWordType
 *
 *  "pzText" points to the character after "words=".
 *  What should follow is a name of a keyword (enumeration) list.
 */
static char*
parseKeyWordType(
    tOptions*     pOpts,
    char*         pzText,
    tOptionValue* pType )
{
    return skipUnknown( pzText );
}


/*  parseLoadMode
 *
 *  "pzText" points to some name character.  We check for "cooked" or
 *  "uncooked" or "keep".  This function should handle any attribute
 *  that does not have an associated value.
 */
static char*
parseLoadMode(
    char*               pzText,
    tOptionLoadMode*    pMode )
{
    {
        size_t len = strlen(zLoadCooked);
        if (strncmp( pzText, zLoadCooked, len ) == 0) {
            if (  (pzText[len] == '>')
               || (pzText[len] == '/')
               || isspace((int)pzText[len])) {
                *pMode = OPTION_LOAD_COOKED;
                return pzText + len;
            }
            goto unknown;
        }
    }

    {
        size_t len = strlen(zLoadUncooked);
        if (strncmp( pzText, zLoadUncooked, len ) == 0) {
            if (  (pzText[len] == '>')
               || (pzText[len] == '/')
               || isspace((int)pzText[len])) {
                *pMode = OPTION_LOAD_UNCOOKED;
                return pzText + len;
            }
            goto unknown;
        }
    }

    {
        size_t len = strlen(zLoadKeep);
        if (strncmp( pzText, zLoadKeep, len ) == 0) {
            if (  (pzText[len] == '>')
               || (pzText[len] == '/')
               || isspace((int)pzText[len])) {
                *pMode = OPTION_LOAD_KEEP;
                return pzText + len;
            }
            goto unknown;
        }
    }

  unknown:
    return skipUnknown( pzText );
}


/*  parseSetMemType
 *
 *  "pzText" points to the character after "members="
 *  What should follow is a name of a "set membership".
 *  A collection of bit flags.
 */
static char*
parseSetMemType(
    tOptions*     pOpts,
    char*         pzText,
    tOptionValue* pType )
{
    return skipUnknown( pzText );
}


/*  parseValueType
 *
 *  "pzText" points to the character after "type="
 */
static char*
parseValueType(
    char*         pzText,
    tOptionValue* pType )
{
    {
        size_t len = strlen(zLtypeString);
        if (strncmp( pzText, zLtypeString, len ) == 0) {
            if ((pzText[len] == '>') || isspace((int)pzText[len])) {
                pType->valType = OPARG_TYPE_STRING;
                return pzText + len;
            }
            goto unknown;
        }
    }

    {
        size_t len = strlen(zLtypeInteger);
        if (strncmp( pzText, zLtypeInteger, len ) == 0) {
            if ((pzText[len] == '>') || isspace((int)pzText[len])) {
                pType->valType = OPARG_TYPE_NUMERIC;
                return pzText + len;
            }
            goto unknown;
        }
    }

    {
        size_t len = strlen(zLtypeBool);
        if (strncmp( pzText, zLtypeBool, len ) == 0) {
            if ((pzText[len] == '>') || isspace(pzText[len])) {
                pType->valType = OPARG_TYPE_BOOLEAN;
                return pzText + len;
            }
            goto unknown;
        }
    }

    {
        size_t len = strlen(zLtypeKeyword);
        if (strncmp( pzText, zLtypeKeyword, len ) == 0) {
            if ((pzText[len] == '>') || isspace((int)pzText[len])) {
                pType->valType = OPARG_TYPE_ENUMERATION;
                return pzText + len;
            }
            goto unknown;
        }
    }

    {
        size_t len = strlen(zLtypeSetMembership);
        if (strncmp( pzText, zLtypeSetMembership, len ) == 0) {
            if ((pzText[len] == '>') || isspace((int)pzText[len])) {
                pType->valType = OPARG_TYPE_MEMBERSHIP;
                return pzText + len;
            }
            goto unknown;
        }
    }

    {
        size_t len = strlen(zLtypeNest);
        if (strncmp( pzText, zLtypeNest, len ) == 0) {
            if ((pzText[len] == '>') || isspace((int)pzText[len])) {
                pType->valType = OPARG_TYPE_HIERARCHY;
                return pzText + len;
            }
            goto unknown;
        }
    }

  unknown:
    pType->valType = OPARG_TYPE_NONE;
    return skipUnknown( pzText );
}


/*  skipUnknown
 *
 *  Skip over some unknown attribute
 */
static char*
skipUnknown( char* pzText )
{
    for (;; pzText++) {
        if (isspace( (int)*pzText ))  return pzText;
        switch (*pzText) {
        case NUL: return NULL;
        case '/':
        case '>': return pzText;
        }
    }
}


/*  validateOptionsStruct
 *
 *  Make sure the option descriptor is there and that we understand it.
 *  This should be called from any user entry point where one needs to
 *  worry about validity.  (Some entry points are free to assume that
 *  the call is not the first to the library and, thus, that this has
 *  already been called.)
 */
LOCAL tSuccess
validateOptionsStruct( tOptions* pOpts, char const* pzProgram )
{
    if (pOpts == NULL) {
        fputs( zAO_Bad, stderr );
        exit( EX_CONFIG );
    }

    /*
     *  IF the client has enabled translation and the translation procedure
     *  is available, then go do it.
     */
    if (  ((pOpts->fOptSet & OPTPROC_TRANSLATE) != 0)
       && (pOpts->pTransProc != 0) ) {
        (*pOpts->pTransProc)();
        pOpts->fOptSet &= ~OPTPROC_TRANSLATE;
    }

    /*
     *  IF the struct version is not the current, and also
     *     either too large (?!) or too small,
     *  THEN emit error message and fail-exit
     */
    if (  ( pOpts->structVersion  != OPTIONS_STRUCT_VERSION  )
       && (  (pOpts->structVersion > OPTIONS_STRUCT_VERSION  )
          || (pOpts->structVersion < OPTIONS_MINIMUM_VERSION )
       )  )  {

        fprintf( stderr, zAO_Err, pOpts->origArgVect[0],
                 NUM_TO_VER( pOpts->structVersion ));
        if (pOpts->structVersion > OPTIONS_STRUCT_VERSION )
            fputs( zAO_Big, stderr );
        else
            fputs( zAO_Sml, stderr );

        return FAILURE;
    }

    /*
     *  If the program name hasn't been set, then set the name and the path
     *  and the set of equivalent characters.
     */
    if (pOpts->pzProgName == NULL) {
        char const* pz = strrchr( pzProgram, DIRCH );

        if (pz == NULL)
             pOpts->pzProgName = pzProgram;
        else pOpts->pzProgName = pz+1;

        pOpts->pzProgPath = pzProgram;

        /*
         *  when comparing long names, these are equivalent
         */
        strequate( zSepChars );
    }

    return SUCCESS;
}


/**
 * Local Variables:
 * mode: C
 * c-file-style: "stroustrup"
 * indent-tabs-mode: nil
 * End:
 * end of autoopts/configfile.c */