UPX Pack Executable Action

UPX () is a free (open source) packer for executable programs. UPX packed applications take up far less space on disk, in exchange for slightly higher memory use on startup. UPX can also pack Win32 DLLS.

For more information on UPX, see

For more specific technical information on UPX options, see the 'upx.doc' file that comes with UPX.

Executable

Binary file to pack

UPX can pack executable files, Win32 DLLs and screensavers.

If you do not specify an output file, the compressed executable will be written over the original file. You cannot compressed an already-compressed executable.

Output to file

The name and location of the resulting compressed file.

Delete the output file if it already exists

Specify this option if previous output files should be deleted.

Verbosity

Specify the level of output from the UPX utility.

Verbose output

Reports all information possible throughout the packing of the binary.

Normal output

Reports the default level of information about the packing process.

Suppress warnings

No warnings will be reported during the packing process. Not recommended as issues arising in the packing process will not be visible in build logs.

Suppress errors

No errors will be reported during the packing process. Not recommended as issues arising in the the packing process will not be visible in the build logs.

Suppress everything

Nothing will be reported during the packing process. Not recommended. The reason? Sorry, that is suppressed.

Compression

Compression Level

Compression levels range from 1 (fastest) to 9 (slower, better) and then "best" (maximum compression.)

Compression Method

UPX currently supports two compression algorithms, NRV2B and NRV2D. UPX's creators recommend trying both and seeing which gives better results for your application.

Level of memory use

Specify the amount of memory which UPX will use for packing the executable.

Higher numbers will use more memory to provide faster results and (slightly) better compression. Setting the value to 999999 will use as much available memory as required for the best results.

Options

Compress the export section

Equivalent of (--compress-exports=0/1)

If checked, the export section of the Win32/PE executable will be compressed. This gives a good saving in size, but does not work with all applications. See the UPX documentation for more details.

Compress resources / Compress icons

Equivalent of (--compress-resources=0/1 and --compress-icons=0/1/2)

UPX can be set to compress application resources, including icons. See the UPX documentation for more details.

Compress resources

Compress icons

Strip Relocation Records

Equivalent of (--strip-relocs=0/1)

If checked, UPX will strip the relocation records of executables. See the UPX documentation for more details.

Force compression even with unknown header fields

Equivalent of (--force)

If this option is checked, it forces UPX to compress the executable even if it finds unknown data in the executable header fields. This may render your application unusable. See the UPX documentation for more details.

Use all filters

Equivalent of (--all-filters)

If this option is checked, it will compress the program several times using every available pre-processing filter.