Ubuntu Manpage: crystal — Compiler for the Crystal language.

NAME

     crystal — Compiler for the Crystal language.

SYNOPSIS

     crystal command [switches] programfile -- [arguments]

DESCRIPTION

     Crystal is a statically type-checked programming language. It was created with the beauty of
     Ruby and the performance of C in mind.

USAGE

     You can compile and run a program by invoking the compiler with a single filename:

     crystal some_program.cr

     Crystal files usually end with the .cr extension, though this is not mandatory.

     Alternatively you can use the run command:

     crystal run some_program.cr

     To create an executable use the build command:

     crystal build some_program.cr

     This will create an executable named "some_program".

     Note that by default the generated executables are not fully optimized.  To turn
     optimizations on, use the --release flag:

     crystal build --release some_program.cr

     Make sure to always use --release for production-ready executables and when performing
     benchmarks.

     The optimizations are not turned on by default because the compile times are much faster
     without them and the performance of the program is still pretty good without them, so it
     allows to use the crystal command almost to be used as if it was an interpreter.

OPTIONS

The crystal command accepts the following options

init TYPE [DIR | NAME DIR]

Generates a new Crystal project.

TYPE is one of:

lib Creates a library skeleton
app Creates an application skeleton

This initializes the lib/app project folder as a git repository, with a license
file, a README file, a shard.yml for use with shards (the Crystal dependency
manager), a .gitignore file, and src and spec folders.

DIR - directory where project will be generated

NAME - name of project to be generated (default: basename of DIR)

Options:

-f, --force
Force overwrite existing files.
-s, --skip-existing
Skip existing files.

build [options] [programfile] [--] [arguments]

Compile program.

Options:

--cross-compile
Generate an object file for cross compilation and prints the command to
build the executable. The object file should be copied to the target
system and the printed command should be executed there. This flag
mainly exists for porting the compiler to new platforms, where possible
run the compiler on the target platform directly.
-d, --debug
Generate the output with symbolic debug symbols. These are read when
debugging the built program with tools like lldb, gdb, valgrind etc. and
provide mappings to the original source code for those tools.
--no-debug
Generate the output without any symbolic debug symbols.
--lto FLAG
Use ThinLTO --lto=thin.
-D FLAG, --define FLAG
Define a compile-time flag. This is useful to conditionally define
types, methods, or commands based on flags available at compile time.
The default flags are from the target triple given with --target-triple
or the hosts default, if none is given.
--emit [asm|llvm-bc|llvm-ir|obj]
Comma separated list of types of output for the compiler to emit. You
can use this to see the generated LLVM IR, LLVM bitcode, assembly, and
object files.
-f text|json, --format text|json
Format of output. Defaults to text. The json format can be used to get a
more parser-friendly output.
--error-trace
Show full error trace.
--ll Dump LLVM assembly file to output directory.
--link-flags FLAGS
Pass additional flags to the linker. Though you can specify those flags
on the source code, this is useful for passing environment specific
information directly to the linker, like non-standard library paths or
names. For more information on specifying linker flags on source, you
can read the "C bindings" section of the documentation available on the
official web site.
--mcpu CPU
Specify a specific CPU to generate code for. This will pass a -mcpu flag
to LLVM, and is only intended to be used for cross-compilation. For a
list of available CPUs, invoke "llvm-as < /dev/null | llc -march=xyz
-mcpu=help". Passing --mcpu native will pass the host CPU name to tune
performance for the host.
--mattr CPU
Override or control specific attributes of the target, such as whether
SIMD operations are enabled or not. The default set of attributes is set
by the current CPU. This will pass a -mattr flag to LLVM, and is only
intended to be used for cross-compilation. For a list of available
attributes, invoke "llvm-as < /dev/null | llc -march=xyz -mattr=help".
--mcmodel -default|kernel|small|medium|large
Specifies a specific code model to generate code for. This will pass a
--code-model flag to LLVM.
--no-color
Disable colored output.
--no-codegen
Don't do code generation, just parse the file.
-o Specify filename of output.
--prelude
Specify prelude to use. The default one initializes the garbage
collector. You can also use --prelude=empty to use no preludes. This can
be useful for checking code generation for a specific source code file.
--release
Turn on optimizations for the generated code, which are disabled by
default.
--error-trace
Show full stack trace. Disabled by default, as the full trace usually
makes error messages less readable and not always deliver relevant
information.
-s, --stats
Print statistics about the different compiler stages for the current
build. Output time and used memory for each compiler process.
-p, --progress
Print statistics about the progress for the current build.
-t, --time
Print statistics about the execution time.
--single-module
Generate a single LLVM module.
--threads NUM
Maximum number of threads to use for code generation. The default is 8
threads.
--target TRIPLE
Enable target triple; intended to use for cross-compilation. See llvm
documentation for more information about target triple.
--verbose
Display the commands executed by the system.
--static Create a statically linked executable.
--stdin-filename FILENAME
Source file name to be read from STDIN.

docs

Generate documentation from comments using a subset of markdown. The output is
saved in html format on the created docs/ folder. More information about
documentation conventions can be found at https://crystal-
lang.org/docs/conventions/documenting_code.html.

Options:

--project-name NAME
Set the project name. The default value is extracted from shard.yml if
available.

In case no default can be found, this option is mandatory.
--project-version VERSION
Set the project version. The default value is extracted from current git
commit or shard.yml if available.

In case no default can be found, this option is mandatory.
--json-config-url URL
Set the URL pointing to a config file (used for discovering versions).
--source-refname REFNAME
Set source refname (e.g. git tag, commit hash). The default value is
extracted from current git commit if available.

If this option is missing and can't be automatically determined, the
generator can't produce source code links.
--source-url-pattern URL
Set URL pattern for source code links. The default value is extracted
from git remotes ("origin" or first one) if available and the provider's
URL pattern is recognized.

Supported replacement tags:

%{refname} commit reference
%{path} path to source file inside the repository
%{filename}
basename of the source file
%{line} line number

If this option is missing and can't be automatically determined, the
generator can't produce source code links.
-o DIR, --output DIR
Set the output directory (default: ./docs).
-b URL, --canonical-base-url URL
Indicate the preferred URL with rel="canonical" link element.
-b URL, --sitemap-base-url URL
Set the sitemap base URL. Sitemap will only be generated when this
option is set.
--sitemap-priority PRIO
Set the priority assigned to sitemap entries (default: 1.0).
--sitemap-changefreq FREQ
Set the changefreq assigned to sitemap entries (default: never).

env [variables]

Print Crystal-specific environment variables in a format compatible with shell
scripts. If one or more variable names are given as arguments, it prints only the
value of each named variable on its own line.

Variables:

CRYSTAL_CACHE_DIR
Please see ENVIRONMENT VARIABLES.

CRYSTAL_LIBRARY_PATH
Please see ENVIRONMENT VARIABLES.

CRYSTAL_PATH
Please see ENVIRONMENT VARIABLES.

CRYSTAL_VERSION
Contains Crystal version.

eval[options][source]

Evaluate code from arguments or, if no arguments are passed, from the standard
input. Useful for experiments.

Options:

-d,--debug
Generate the output with symbolic debug symbols. These are read when
debugging the built program with tools like lldb, gdb, valgrind etc. and
provide mappings to the original source code for those tools.
--no-debug
Generate the output without any symbolic debug symbols.
-DFLAG,--defineFLAG
Define a compile-time flag. This is useful to conditionally define
types, methods, or commands based on flags available at compile time.
The default flags are from the target triple given with --target-triple
or the hosts default, if none is given.
--error-trace
Show full error trace.
--release
Turn on optimizations for the generated code, which are disabled by
default.
-s,--stats
Print statistics about the different compiler stages for the current
build. Output time and used memory for each compiler process.
-p,--progress
Print statistics about the progress for the current build.
-t,--time
Print statistics about the execution time.
--no-color
Disable colored output.

play[options][file]

Starts the crystal playground server on port 8080, by default.

Options:

-pPORT,--portPORT
Run the playground on the specified port. Default is 8080.
-bHOST,--bindingHOST
Bind the playground to the specified IP.
-v,--verbose
Display detailed information of the executed code.

run[options][programfile][--][arguments]

The default command. Compile and run program.

Options: Same as the build options.

spec[options][files]

Compile and run specs (in spec directory).

Options:

tool[tool][switches][programfile][--][arguments]

Run a tool. The available tools are: context, format, hierarchy, implementations,
and types.

Tools:

context
Show context for given location.

expand Show macro expansion for given location.

format Format project, directories and/or files with the coding style used
in the standard library. You can use the --checkflag to check
whether the formatter would make any changes.

hierarchy
Show hierarchy of types from file. Also show class and struct
members, with type and size. Types can be filtered with a regex by
using the -eflag.

implementations
Show implementations for a given call. Use --cursorto specify the
cursor position. The format for the cursor position is
file:line:column.

types Show type of main variables of file.

help,--help,-h

Show help. Option --help or -h can also be added to each command for command-
specific help.

version,--version,-v

Show version.

ENVIRONMENTVARIABLES

CRYSTAL_CACHE_DIR
Defines path where Crystal caches partial compilation results for faster
subsequent builds. This path is also used to temporarily store executables when
Crystal programs are run with 'crystal run' rather than 'crystal build'.

CRYSTAL_LIBRARY_PATH
Defines paths where Crystal searches for (binary) libraries. Multiple paths can be
separated by ":". These paths are passed to the linker as `-L` flags.

The pattern '$ORIGIN' at the start of the path expands to the directory where the
compiler binary is located. For example, '$ORIGIN/../lib/crystal' resolves the
standard library path relative to the compiler location in a generic way,
independent of the absolute paths (assuming the relative location is correct).

CRYSTAL_PATH
Defines paths where Crystal searches for required source files. Multiple paths can
be separated by ":".

The pattern '$ORIGIN' at the start of the path expands to the directory where the
compiler binary is located. For example, '$ORIGIN/../share/crystal/src' resolves
the standard library path relative to the compiler location in a generic way,
independent of the absolute paths (assuming the relative location is correct).

CRYSTAL_OPTS
Defines options for the Crystal compiler to be used besides the command line
arguments. The syntax is identical to the command line arguments. This is handy
when using Crystal in build setups, for example 'CRYSTAL_OPTS=--debug make build'.

NAME

SYNOPSIS

DESCRIPTION

USAGE

OPTIONS

ENVIRONMENTVARIABLES

SEEALSO