julia - Man Page

high-level, high-performance dynamic programming language for technical computing

Examples (TL;DR)


julia [option] [program] [args..]


Julia is a high-level, high-performance dynamic programming language for technical computing, with syntax that is familiar to users of other technical computing environments. It provides a sophisticated compiler, distributed parallel execution, numerical accuracy, and an extensive mathematical function library. The library, largely written in Julia itself, also integrates mature, best-of-breed C and Fortran libraries for linear algebra, random number generation, signal processing, and string processing. In addition, the Julia developer community is contributing a number of external packages through Julia's built-in package manager at a rapid pace. Julia programs are organized around multiple dispatch; by defining functions and overloading them for different combinations of argument types, which can also be user-defined. For a more in-depth discussion of the rationale and advantages of Julia over other systems, please see the online manual: https://docs.julialang.org

If a Julia source file is given as a program (optionally followed by
arguments in args) Julia will execute the program and exit.

Command-Line Options

-v,  --version

Display version information

-h,  --help

Print help message


Set <dir> as the home project/environment. The default @. option will search through parent directories until a Project.toml or JuliaProject.toml file is found.

-J,  --sysimage <file>

Start up with the given system image file


Use precompiled code from system image if available

-H,  --home <dir>

Set location of julia executable


Load ~/.julia/config/startup.jl


Enable or disable Julia's default signal handlers

-e,  --eval <expr>

Evaluate <expr>

-E,  --print <expr>

Evaluate <expr> and display the result

-L,  --load <file>

Load <file> immediately on all processors

-t,  --threads <n>

Enable n threads

-p,  --procs <n>

Run n local processes

--machine-file <file>

Run processes on hosts listed in <file>


Interactive mode; REPL runs and isinteractive() is true


Enable or disable startup banner


Enable or disable color text


Load or save history


Enable or disable compiler, or request exhaustive or minimal compilation

-C,  --cpu-target=<target>

Limit usage of cpu features up to <target>

-O,  --optimize

Run time-intensive code optimizations

-O <n>, --optimize=<n>

Set the optimization level to <n>


Enable generation of full debug info

-g <n>

Set the level of debug info generation to <n>


Control whether inlining is permitted (overrides functions declared as @inline)


Emit bounds checks always or never (ignoring declarations)


Always use IEEE semantics for math (ignoring declarations), or adhere to declarations in source code


Enable or disable syntax and method deprecation warnings ('error' turns warnings into errors)


Enable or disable method overwrite warnings

--output-o <name>

Generate an object file (including system image data)

--output-ji <name>

Generate a system image data file (.ji)

--output-bc <name>

Generate LLVM bitcode (.bc)


Generate an incremental output file (rather than complete)

--code-coverage={none|user|all}, --code-coverage

Count executions of source lines (omitting setting is equivalent to 'user')

--track-allocation={none|user|all}, --track-allocation

Count bytes allocated by each source line



Per user startup file.


System-wide startup file.


Please report any bugs using the GitHub issue tracker: https://github.com/julialang/julia/issues?state=open


Contributors: https://github.com/JuliaLang/julia/graphs/contributors


2013-12-10 Julia Programmers' Reference Guide