COMPRESS Option

Syntax

COMPRESS=compression-level

The COMPRESS option specifies the level of compression to be used when building the Help file. Compression levels indicate either no compression, medium compression (approximately 40 percent), or high compression (approximately 50 percent). The higher the compression level, the smaller the Help file. However, the higher the compression, the longer the file takes to build.

Parameter

compression-level

Specifies the level of compression. This parameter can be one of the following values.

Comments

Depending on the level of compression requested, the Help compiler uses either block compression or a combination of block and key-phrase compression:

nBlock compression compresses the topic data into predefined units known as blocks.

nKey-phrase compression combines repeated phrases found within the source file(s).

The Help compiler creates a phrase-table file with a .PH extension if it doesn’t find one in the project root directory. If the Help compiler finds a file with a .PH extension, it uses the file for the current build. Because the .PH file speeds up the compression process when little text has changed since the last build, you might want to keep the phrase file around if you compile the same Help file several times with compression. However, you get maximum compression if you delete the .PH file before starting each build.

Because of these improvements to Help compression, the resulting Help files you build will take up less space on users’ disks, but your setup program may not be able to compress the smaller Help files as much as version 3.0 files. Therefore, when estimating disk-space requirements, you should use sizes relatively close to those achieved with high compression.

Key-phrase compression is the only compression method supported by the version 3.0 Help compiler.

Example

The following shows a typical compression entry in the Help project file:

COMPRESS=off

See Also

[OPTIONS] Section