LHarc, a precursor to the LHA file utility, became one of the standard file
compression/extraction utility in Japan despite its
slowness. I am also pleased that some overseas users have taken to using this
I, however, have continued on my research for a new compression
algorithm even after releasing LHarc to the public. The fruit of my two years of research is incorporated in the new utility, LHA which I would now like to make
Higher compression. LHA offers a higher compression rate than LHarc especially when compressing large files. On the other hand, compression rate is worse for files smaller than few hundred bytes.
Faster file extraction. Extraction algorithm was changed to static Huffman algorith from dynamic Huffman algorithm to decrease file extraction
time. Nevertheless, compression time did not decrease as much as I expected.
Increased memory usage. LHA requires more memory. Use caution when executing LHA from another program or in a child process. When LHA detects memory
shortage, it will try to continue by decreasing compression rate.
Only upward compatible with LHarc. Files compressed by LHA can not be extracted by
However, files compressed by LHarc may be extracted by LHA.