dhcp-varfile.c

来自「this is sample about DHCP-agent」· C语言 代码 · 共 174 行

/* $Header: /cvsroot/dhcp-agent/dhcp-agent/src/dhcp-varfile.c,v 1.6 2002/12/23 00:51:25 actmodern Exp $
 * Copyright 2002 Thamer Alharbash <[e-mail]> 
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in
 * the documentation and/or other materials provided with the
 * distribution.
 * 3. The names of the authors may not be used to endorse or promote
 * products derived from this software without specific prior
 * written permission.
 * 
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 * 
 * varfiles -- variable files. Files with varname or varname = 
 * varvalue for statements.
 *
 * This files are meant to be human readable and be cross platform by writing 
 * the serialized form of all the values.
 */

#define MODULE_NAME "dhcp-varfile"

#include "dhcp-local.h"
#include "dhcp-libutil.h"

#include "dhcp-tokenizer.h"

const char *varfile_get_name(varfile_t *varfile)
{
    return stringbuffer_getstring(varfile->var_name);
}

const char *varfile_get_val(varfile_t *varfile)
{
    return stringbuffer_getstring(varfile->var_val);
}

int varfile_get_lineno(varfile_t *varfile)
{
    return tokenizer_get_line_no(varfile->tokenizer);
}

varfile_t *create_varfile(const char *filename, uint8_t mode)
{
    varfile_t *varfile;

    varfile = xmalloc(sizeof(varfile_t));
    varfile->filename = xstrdup(filename);
    varfile->var_name = stringbuffer_create();
    varfile->var_val = stringbuffer_create();
    varfile->tokenizer = tokenizer_create(filename);
    varfile->mode = mode;
    return varfile;
}

void destroy_varfile(varfile_t *varfile)
{
    tokenizer_destroy(varfile->tokenizer);
    stringbuffer_destroy(varfile->var_name);
    stringbuffer_destroy(varfile->var_val);
    xfree(varfile->filename);
    xfree(varfile);

    return;
}

const char *varfile_get_filename(varfile_t *varfile)
{
    return varfile->filename;
}


int varfile_get_next_varnames(varfile_t *varfile)
{
    token_t token;

    while(1) {

        token = tokenizer_get_next_token(varfile->tokenizer);

        if(token == TOKEN_NEWLINE) /* skip empty lines/comments. */
            continue;

        if(token == TOKEN_EOF)
            return VARFILE_EOF;

        if(token != TOKEN_STRING)
            return VARFILE_PARSE_ERROR;

        /* copy string out into varname */
        stringbuffer_set(varfile->var_name, tokenizer_get_data(varfile->tokenizer));
        token = tokenizer_get_next_token(varfile->tokenizer);

        /* if we don't get an end of statement or eof here it's a parse error. */
        if(token != TOKEN_NEWLINE && token != TOKEN_EOF)
            return VARFILE_PARSE_ERROR;

        return VARFILE_SUCCESS;
    }
}

int varfile_get_next_varval(varfile_t *varfile)
{
    token_t token;

    /* get the name first. */
    while(1) {

        token = tokenizer_get_next_token(varfile->tokenizer);

        if(token == TOKEN_NEWLINE) /* skip empty lines/comments. */
            continue;

        if(token == TOKEN_EOF)
            return VARFILE_EOF;

        if(token != TOKEN_STRING)
            return VARFILE_PARSE_ERROR;

        /* copy string out into varname */
        stringbuffer_set(varfile->var_name, tokenizer_get_data(varfile->tokenizer));
        break;
    }

    token = tokenizer_get_next_token(varfile->tokenizer);

    if(token != TOKEN_ASSIGNMENT)
        return VARFILE_PARSE_ERROR;

    token = tokenizer_get_next_token(varfile->tokenizer);

    if(token != TOKEN_STRING)
        return VARFILE_PARSE_ERROR;

    /* copy string out into var val */
    stringbuffer_set(varfile->var_val, tokenizer_get_data(varfile->tokenizer));

    /* now we need a clean end of statement. */

    token = tokenizer_get_next_token(varfile->tokenizer);

    if(token != TOKEN_NEWLINE && token != TOKEN_EOF)
        return VARFILE_PARSE_ERROR;

    return VARFILE_SUCCESS;
}

/* Get the next var statement from file. */
int varfile_get_next_var(varfile_t *varfile)
{
    switch (varfile->mode) {

    case VARFILE_VARNAMES_MODE:
        return (varfile_get_next_varnames(varfile));

    case VARFILE_VARVAL_MODE:
        return (varfile_get_next_varval(varfile));

    default:
        FATAL_MESSAGE("varfile: file_get_next_var: encountered a fatal bug -- please report this.");
    }

    /* should never get here. */
    return 0;
}