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PROCYON(1) User Commands PROCYON(1)


procyon - manual page for the Procyon Java decompiler


procyon [options] <type names or class/jar files>


Procyon is a Java decompiler handling language enhancements from Java 5 and beyond that most other decompilers don't. It also excels in areas where others fall short. Procyon in particular does well with:
* Enum declarations
* Enum and String switch statements
* Local classes (both anonymous and named)
* Annotations
* Java 8 Lambdas and method references

Procyon offers three output modes:
* Java (default)
* Raw Bytecode (similar to javap, but prettier; run with -r)
* Bytecode AST (an intermediate representation; run with -b, add -u for unoptimized)

One or more types can be passed as an argument to be processed. The input types can be fully-qualified names in dotted or binary form (e.g., java.lang.String or java/lang/String) or relative/absolute file paths (path/to/MyClass.class) or even whole jar files. If a type name is passed, Procyon will attempt to load it out of the user or bootstrap classpath.


-b, --bytecode-ast

Output Bytecode AST instead of Java. Default: false

-ci, --collapse-imports

Collapse multiple imports from the same package into a single wildcard import. Default: false

-cp, --constant-pool

Includes the constant pool when displaying raw bytecode (unnecessary with -v). Default: false

-dl, --debug-line-numbers

For debugging, show Java line numbers as inline comments (implies -ln; requires -o). Default: false


Disable 'for each' loop transforms. Default: false

-eml, --eager-method-loading

Enable eager loading of method bodies (may speed up decompilation of larger archives). Default: false

-ent, --exclude-nested

Exclude nested types when decompiling their enclosing types. Default: false

-ei, --explicit-imports

[DEPRECATED] Explicit imports are now enabled by default. This option will be removed in a future release. Default: false

-eta, --explicit-type-arguments

Always print type arguments to generic methods. Default: false

-fsb, --flatten-switch-blocks

Drop the braces statements around switch sections when possible. Default: false

-?, --help

Display this usage information and exit. Default: false

-jar, --jar-file

[DEPRECATED] Decompile all classes in the specified jar file (disables -ent and -s).

-lc, --light

Use a color scheme designed for consoles with light background colors. Default: false

-lv, --local-variables

Includes the local variable tables when displaying raw bytecode (unnecessary with -v). Default: false

-ll, --log-level

Set the level of log verbosity (0-3). Level 0 disables logging. Default: 0

-mv, --merge-variables

Attempt to merge as many variables as possible. This may lead to fewer declarations, but at the expense of inlining and useful naming. This feature is experimental and may be removed or become the standard behavior in future releases. Default: false

-o, --output-directory

Write decompiled results to specified directory instead of the console.

-r, --raw-bytecode

Output Raw Bytecode instead of Java (to control the level of detail, see: -cp, -lv, -ta, -v). Default: false

-ec, --retain-explicit-casts

Do not remove redundant explicit casts. Default: false

-ps, --retain-pointless-switches

Do not lift the contents of switches having only a default label. Default: false

-ss, --show-synthetic

Show synthetic (compiler-generated) members. Default: false

-sm, --simplify-member-references

Simplify type-qualified member references in Java output [EXPERIMENTAL]. Default: false

-sl, --stretch-lines

Stretch Java lines to match original line numbers (only in combination with -o) [EXPERIMENTAL]. Default: false

-ta, --type-attributes

Includes type attributes when displaying raw bytecode (unnecessary with -v). Default: false


Enable Unicode output (printable non-ASCII characters will not be escaped). Default: false

-u, --unoptimized

Show unoptimized code (only in combination with -b). Default: false

-v, --verbose

Includes more detailed output depending on the output language (currently only supported for raw bytecode). Default: false


Display the decompiler version and exit. Default: false

-ln, --with-line-numbers

Include line numbers in raw bytecode mode; supports Java mode with -o only. Default: false


Decompile a single class to the console:

$ procyon java.lang.String
$ procyon java.util.Collections

Decompile a whole jar to a directory:

$ procyon myJar.jar -o out

Decompile a single class from a jar:

$ CLASSPATH=myJar.jar procyon com.example.Foo


October 2016 procyon 0.5.32