In addition to decompressing a complete file at a time, an application can decompress compressed files a portion at a time by using the LZSeek and LZRead functions. These functions are particularly useful when it is necessary to extract parts of large files. For example, a font manufacturer may have compressed files containing font metrics in addition to character data. To use the information in these files, an application would need to decompress the file; however, most applications would use only part of the file at any particular time. When the user queried the font metrics, the application would extract data from the header. When the user rendered text output, the application would reposition the file pointer by calling LZSeek and extract the character data.