xmlio.c

libxml,在UNIX/LINUX下非常重要的一个库,为XML相关应用提供方便.目前上载的是最新版本,若要取得最新版本,请参考里面的readme.

        xmlOutputCallbackTable[i].writecallback = NULL;
        xmlOutputCallbackTable[i].closecallback = NULL;
    }

    xmlOutputCallbackNr = 0;
    xmlOutputCallbackInitialized = 0;
}
#endif /* LIBXML_OUTPUT_ENABLED */

/************************************************************************
 *									*
 *		Standard I/O for file accesses				*
 *									*
 ************************************************************************/

/**
 * xmlCheckFilename:
 * @path:  the path to check
 *
 * function checks to see if @path is a valid source
 * (file, socket...) for XML.
 *
 * if stat is not available on the target machine,
 * returns 1.  if stat fails, returns 0 (if calling
 * stat on the filename fails, it can't be right).
 * if stat succeeds and the file is a directory,
 * returns 2.  otherwise returns 1.
 */

int
xmlCheckFilename (const char *path)
{
#ifdef HAVE_STAT
    struct stat stat_buffer;

    if (path == NULL)
        return(0);

    if (stat(path, &stat_buffer) == -1)
        return 0;

#ifdef S_ISDIR
    if (S_ISDIR(stat_buffer.st_mode)) {
        return 2;
    }
#endif
#endif
    if (path == NULL)
        return(0);

    return 1;
}

static int
xmlNop(void) {
    return(0);
}

/**
 * xmlFdRead:
 * @context:  the I/O context
 * @buffer:  where to drop data
 * @len:  number of bytes to read
 *
 * Read @len bytes to @buffer from the I/O channel.
 *
 * Returns the number of bytes written
 */
static int
xmlFdRead (void * context, char * buffer, int len) {
    int ret;

    ret = read((int) (long) context, &buffer[0], len);
    if (ret < 0) xmlIOErr(0, "read()");
    return(ret);
}

#ifdef LIBXML_OUTPUT_ENABLED
/**
 * xmlFdWrite:
 * @context:  the I/O context
 * @buffer:  where to get data
 * @len:  number of bytes to write
 *
 * Write @len bytes from @buffer to the I/O channel.
 *
 * Returns the number of bytes written
 */
static int
xmlFdWrite (void * context, const char * buffer, int len) {
    int ret;

    ret = write((int) (long) context, &buffer[0], len);
    if (ret < 0) xmlIOErr(0, "write()");
    return(ret);
}
#endif /* LIBXML_OUTPUT_ENABLED */

/**
 * xmlFdClose:
 * @context:  the I/O context
 *
 * Close an I/O channel
 *
 * Returns 0 in case of success and error code otherwise
 */
static int
xmlFdClose (void * context) {
    int ret;
    ret = close((int) (long) context);
    if (ret < 0) xmlIOErr(0, "close()");
    return(ret);
}

/**
 * xmlFileMatch:
 * @filename:  the URI for matching
 *
 * input from FILE *
 *
 * Returns 1 if matches, 0 otherwise
 */
int
xmlFileMatch (const char *filename ATTRIBUTE_UNUSED) {
    return(1);
}

/**
 * xmlFileOpen_real:
 * @filename:  the URI for matching
 *
 * input from FILE *, supports compressed input
 * if @filename is " " then the standard input is used
 *
 * Returns an I/O context or NULL in case of error
 */
static void *
xmlFileOpen_real (const char *filename) {
    const char *path = NULL;
    FILE *fd;

    if (filename == NULL)
        return(NULL);

    if (!strcmp(filename, "-")) {
	fd = stdin;
	return((void *) fd);
    }

    if (!xmlStrncasecmp(BAD_CAST filename, BAD_CAST "file://localhost/", 17))
#if defined (_WIN32) || defined (__DJGPP__) && !defined(__CYGWIN__)
	path = &filename[17];
#else
	path = &filename[16];
#endif
    else if (!xmlStrncasecmp(BAD_CAST filename, BAD_CAST "file:///", 8)) {
#if defined (_WIN32) || defined (__DJGPP__) && !defined(__CYGWIN__)
	path = &filename[8];
#else
	path = &filename[7];
#endif
    } else 
	path = filename;

    if (path == NULL)
	return(NULL);
    if (!xmlCheckFilename(path))
        return(NULL);

#if defined(WIN32) || defined (__DJGPP__) && !defined (__CYGWIN__)
    fd = fopen(path, "rb");
#else
    fd = fopen(path, "r");
#endif /* WIN32 */
    if (fd == NULL) xmlIOErr(0, path);
    return((void *) fd);
}

/**
 * xmlFileOpen:
 * @filename:  the URI for matching
 *
 * Wrapper around xmlFileOpen_real that try it with an unescaped
 * version of @filename, if this fails fallback to @filename
 *
 * Returns a handler or NULL in case or failure
 */
void *
xmlFileOpen (const char *filename) {
    char *unescaped;
    void *retval;

    unescaped = xmlURIUnescapeString(filename, 0, NULL);
    if (unescaped != NULL) {
	retval = xmlFileOpen_real(unescaped);
	xmlFree(unescaped);
    } else {
	retval = xmlFileOpen_real(filename);
    }
    return retval;
}

#ifdef LIBXML_OUTPUT_ENABLED
/**
 * xmlFileOpenW:
 * @filename:  the URI for matching
 *
 * output to from FILE *,
 * if @filename is "-" then the standard output is used
 *
 * Returns an I/O context or NULL in case of error
 */
static void *
xmlFileOpenW (const char *filename) {
    const char *path = NULL;
    FILE *fd;

    if (!strcmp(filename, "-")) {
	fd = stdout;
	return((void *) fd);
    }

    if (!xmlStrncasecmp(BAD_CAST filename, BAD_CAST "file://localhost/", 17))
#if defined (_WIN32) || defined (__DJGPP__) && !defined(__CYGWIN__)
	path = &filename[17];
#else
	path = &filename[16];
#endif
    else if (!xmlStrncasecmp(BAD_CAST filename, BAD_CAST "file:///", 8)) {
#if defined (_WIN32) || defined (__DJGPP__) && !defined(__CYGWIN__)
	path = &filename[8];
#else
	path = &filename[7];
#endif
    } else 
	path = filename;

    if (path == NULL)
	return(NULL);

    fd = fopen(path, "wb");
    if (fd == NULL) xmlIOErr(0, path);
    return((void *) fd);
}
#endif /* LIBXML_OUTPUT_ENABLED */

/**
 * xmlFileRead:
 * @context:  the I/O context
 * @buffer:  where to drop data
 * @len:  number of bytes to write
 *
 * Read @len bytes to @buffer from the I/O channel.
 *
 * Returns the number of bytes written or < 0 in case of failure
 */
int
xmlFileRead (void * context, char * buffer, int len) {
    int ret;
    if ((context == NULL) || (buffer == NULL)) 
        return(-1);
    ret = fread(&buffer[0], 1,  len, (FILE *) context);
    if (ret < 0) xmlIOErr(0, "fread()");
    return(ret);
}

#ifdef LIBXML_OUTPUT_ENABLED
/**
 * xmlFileWrite:
 * @context:  the I/O context
 * @buffer:  where to drop data
 * @len:  number of bytes to write
 *
 * Write @len bytes from @buffer to the I/O channel.
 *
 * Returns the number of bytes written
 */
static int
xmlFileWrite (void * context, const char * buffer, int len) {
    int items;

    if ((context == NULL) || (buffer == NULL)) 
        return(-1);
    items = fwrite(&buffer[0], len, 1, (FILE *) context);
    if ((items == 0) && (ferror((FILE *) context))) {
        xmlIOErr(0, "fwrite()");
	return(-1);
    }
    return(items * len);
}
#endif /* LIBXML_OUTPUT_ENABLED */

/**
 * xmlFileClose:
 * @context:  the I/O context
 *
 * Close an I/O channel
 *
 * Returns 0 or -1 in case of error
 */
int
xmlFileClose (void * context) {
    FILE *fil;
    int ret;

    if (context == NULL)
        return(-1);
    fil = (FILE *) context;
    if ((fil == stdout) || (fil == stderr)) {
        ret = fflush(fil);
	if (ret < 0)
	    xmlIOErr(0, "fflush()");
	return(0);
    }
    if (fil == stdin)
	return(0);
    ret = ( fclose((FILE *) context) == EOF ) ? -1 : 0;
    if (ret < 0)
        xmlIOErr(0, "fclose()");
    return(ret);
}

/**
 * xmlFileFlush:
 * @context:  the I/O context
 *
 * Flush an I/O channel
 */
static int
xmlFileFlush (void * context) {
    int ret;

    if (context == NULL)
        return(-1);
    ret = ( fflush((FILE *) context) == EOF ) ? -1 : 0;
    if (ret < 0)
        xmlIOErr(0, "fflush()");
    return(ret);
}

#ifdef HAVE_ZLIB_H
/************************************************************************
 *									*
 *		I/O for compressed file accesses			*
 *									*
 ************************************************************************/
/**
 * xmlGzfileMatch:
 * @filename:  the URI for matching
 *
 * input from compressed file test
 *
 * Returns 1 if matches, 0 otherwise
 */
static int
xmlGzfileMatch (const char *filename ATTRIBUTE_UNUSED) {
    return(1);
}

/**
 * xmlGzfileOpen_real:
 * @filename:  the URI for matching
 *
 * input from compressed file open
 * if @filename is " " then the standard input is used
 *
 * Returns an I/O context or NULL in case of error
 */
static void *
xmlGzfileOpen_real (const char *filename) {
    const char *path = NULL;
    gzFile fd;

    if (!strcmp(filename, "-")) {
        fd = gzdopen(dup(0), "rb");
	return((void *) fd);
    }

    if (!xmlStrncasecmp(BAD_CAST filename, BAD_CAST "file://localhost/", 17))
#if defined (_WIN32) || defined (__DJGPP__) && !defined(__CYGWIN__)
	path = &filename[17];
#else
	path = &filename[16];
#endif
    else if (!xmlStrncasecmp(BAD_CAST filename, BAD_CAST "file:///", 8)) {
#if defined (_WIN32) || defined (__DJGPP__) && !defined(__CYGWIN__)
	path = &filename[8];
#else
	path = &filename[7];
#endif
    } else 
	path = filename;

    if (path == NULL)
	return(NULL);
    if (!xmlCheckFilename(path))
        return(NULL);

    fd = gzopen(path, "rb");
    return((void *) fd);
}

/**
 * xmlGzfileOpen:
 * @filename:  the URI for matching
 *
 * Wrapper around xmlGzfileOpen if the open fais, it will
 * try to unescape @filename
 */
static void *
xmlGzfileOpen (const char *filename) {
    char *unescaped;
    void *retval;

    retval = xmlGzfileOpen_real(filename);
    if (retval == NULL) {
	unescaped = xmlURIUnescapeString(filename, 0, NULL);
	if (unescaped != NULL) {
	    retval = xmlGzfileOpen_real(unescaped);
	}
	xmlFree(unescaped);
    }
    return retval;
}

#ifdef LIBXML_OUTPUT_ENABLED
/**
 * xmlGzfileOpenW:
 * @filename:  the URI for matching
 * @compression:  the compression factor (0 - 9 included)
 *
 * input from compressed file open
 * if @filename is " " then the standard input is used
 *
 * Returns an I/O context or NULL in case of error
 */
static void *
xmlGzfileOpenW (const char *filename, int compression) {
    const char *path = NULL;
    char mode[15];
    gzFile fd;

    snprintf(mode, sizeof(mode), "wb%d", compression);
    if (!strcmp(filename, "-")) {
        fd = gzdopen(dup(1), mode);
	return((void *) fd);
    }

    if (!xmlStrncasecmp(BAD_CAST filename, BAD_CAST "file://localhost/", 17))
#if defined (_WIN32) || defined (__DJGPP__) && !defined(__CYGWIN__)
	path = &filename[17];
#else
	path = &filename[16];
#endif
    else if (!xmlStrncasecmp(BAD_CAST filename, BAD_CAST "file:///", 8)) {
#if defined (_WIN32) || defined (__DJGPP__) && !defined(__CYGWIN__)
	path = &filename[8];
#else
	path = &filename[7];
#endif
    } else 
	path = filename;

    if (path == NULL)
	return(NULL);

    fd = gzopen(path, mode);
    return((void *) fd);
}
#endif /* LIBXML_OUTPUT_ENABLED */

/**
 * xmlGzfileRead:
 * @context:  the I/O context
 * @buffer:  where to drop data
 * @len:  number of bytes to write
 *
 * Read @len bytes to @buffer from the compressed I/O channel.
 *
 * Returns the number of bytes written
 */
static int
xmlGzfileRead (void * context, char * buffer, int len) {
    int ret;

    ret = gzread((gzFile) context, &buffer[0], len);
    if (ret < 0) xmlIOErr(0, "gzread()");
    return(ret);
}

#ifdef LIBXML_OUTPUT_ENABLED
/**
 * xmlGzfileWrite:
 * @context:  the I/O context
 * @buffer:  where to drop data
 * @len:  number of bytes to write
 *
 * Write @len bytes from @buffer to the compressed I/O channel.
 *
 * Returns the number of bytes written
 */
static int
xmlGzfileWrite (void * context, const char * buffer, int len) {
    int ret;

    ret = gzwrite((gzFile) context, (char *) &buffer[0], len);
    if (ret < 0) xmlIOErr(0, "gzwrite()");
    return(ret);
}
#endif /* LIBXML_OUTPUT_ENABLED */

/**
 * xmlGzfileClose:
 * @context:  the I/O context
 *
 * Close a compressed I/O channel
 */
static int
xmlGzfileClose (void * context) {
    int ret;

    ret =  (gzclose((gzFile) context) == Z_OK ) ? 0 : -1;