The stack script
command¶
stack script [--package PACKAGE] FILE
[-- ARGUMENT(S) (e.g. stack script X.hs -- argument(s) to program)]
[--compile | --optimize] [--[no-]use-root] [--ghc-options OPTIONS]
[--extra-dep PACKAGE-VERSION] [--no-run]
The stack script
command either runs a specified Haskell source file (using
GHC's runghc
) or, optionally, compiles such a file (using GHC) and, by
default, runs it.
Unlike stack ghc
and stack runghc
, the command ignores all Stack YAML
configuration files (global and project-level). A snapshot must be specified on
the command line (with the --resolver
option). For example:
or, equivalently:
The stack script
command behaves as if the --install-ghc
flag had been
passed at the command line.
Everything after --
on the command line is interpreted as a command line
argument to be passed to what is run.
A package can be added to the snapshot on the command line with the
--extra-dep
option (which can be specified multiple times).
Each required package can be specified by name on the command line with the
--package
option (which can be specified multiple times). A single --package
option can also refer to a list of package names, separated by a space or comma
character. If the package is not in the snapshot, the most recent version on
Hackage will be obtained. If no packages are specified in that way, all the
required packages that are in the snapshot will be deduced by reference to the
import
statements in the source file. The base
package associated with the
version of GHC specified by the snapshot is always available.
The source file can be compiled by passing either the --compile
flag (no
optimization) or the --optimize
flag (compilation with optimization). If the
file is compiled, passing the --no-run
flag will mean the compiled code is not
run.
By default, all the compilation outputs (including the executable) are written
to the directory of the source file. Pass the --use-root
flag to write such
outputs to a script-specific location in the scripts
directory of the Stack
root. The location reflects the absolute path to the source file, but ignoring
the drive. This can avoid clutter in the source file directory.
Additional options can be passed to GHC using the --ghc-options
option.
Examples¶
For example, Haskell source file MyScript.hs
at location
<drive>Users/jane/my-project
(where <drive>
could be /
on Unix-like
operating systems or C:/
or similar on Windows):
module Main (main) where
import Data.List (intercalate)
import System.Environment (getArgs)
import Acme.Missiles (launchMissiles)
main :: IO ()
main = do
advices <- getArgs
launchMissiles
putStrLn $ intercalate "\n" advices
can be compiled and run, with arguments, with:
stack --resolver lts-20.4 script --package acme-missiles --compile MyScript.hs -- "Don't panic!" "Duck and cover!"
All the compilation outputs (like Main.hi
, Main.o
, and the executable
MyScript
) will be written to the my-project
directory.
If compiled and run with the additional flag --use-root
, all the compilation
outputs will be written to a directory named MyScript.hs
at
Users/jane/my-project/
in the scripts
directory of the Stack root.