turtle
Shell programming, Haskell-style
| LTS Haskell 24.16: | 1.6.2@rev:3 |
| Stackage Nightly 2025-07-14: | 1.6.2@rev:3 |
| Latest on Hackage: | 1.6.2@rev:3 |
turtle-1.6.2@sha256:75710c60388e572bc17cbb08a81cbb4537f2207f8dcf187e9b1928d1e0b023a6,5767Module documentation for 1.6.2
turtle is a reimplementation of the Unix command line environment
in Haskell so that you can use Haskell as both a shell and a scripting
language.
Features include:
Batteries included: Command an extended suite of predefined utilities
Interoperability: You can still run external shell commands
Portability: Works on Windows, OS X, and Linux
Exception safety: Safely acquire and release resources
Streaming: Transform or fold command output in constant space
Patterns: Use typed regular expressions that can parse structured values
Formatting: Type-safe
printf-style text formattingModern: Supports
text
Read Turtle.Tutorial for a detailed tutorial or Turtle.Prelude for a
quick-start guide
turtle is designed to be beginner-friendly, but as a result lacks certain
features, like tracing commands. If you feel comfortable using turtle
then you should also check out the Shelly library which provides similar
functionality.
Changes
1.6.2
1.6.1
- BUG FIX: Fix
turtleto build on Windows - BUG FIX:
stripPrefixandcommonPrefixnow correctly handle files with extensions- For example, before this fix
stripPrefix "./" "./foo.bar"would returnJust "foo/.bar"
- For example, before this fix
1.6.0
- BREAKING CHANGE: Switch to the
FilePathtype frombaseinstead ofsystem-filepath- This is a breaking change for a couple of reasons:
- The
FilePathtype has changed, so the API is not backwards-compatible- The thing most likely to break is if you directly imported utilities
from the
system-filepathorsystem-fileiopackages to operate onturtle’sFilePaths- If that happens, you should first check if the
Turtlemodule exports a utility of the same name. If so, then switch to that - If there is no equivalent substitute from the
Turtlemodule then you will have to change your code to use the closest equivalent utility from thefilepathordirectorypackage - If you were previously using any of the
system-filepathorsystem-fileioutilities re-exported from theTurtlemodule then those utilities will not break as they have been replaced with versions compatible with theFilePathtype frombase
- If that happens, you should first check if the
- The second thing most likely to break is any code that relies on
typeclasses since because if you defined any instances for the
FilePathtype exported byturtlethen those instances will now overlap with any instances defined for theStringtype - The conversion utilities (e.g.
toText,encodeString) will still work, so code that used those conversion utilities should be less affected by this change
- The thing most likely to break is if you directly imported utilities
from the
- The behavior of the
collapseutility is subtly differentcollapseno longer interprets..in paths- This new behavior is more correct in the presence of symlinks, so the change is (hopefully) an improvement to downstream code
- The
- The new API strives to match the old behavior as closely as possible
- … so this should (hopefully) not break too much code in practice
- With the exception of the
collapsefunction the new API should be bug-for-bug compatible with the old API- Most of the surprising behavior inherited from the old API is around
how
.and..are handled in pathsparent ".." == "."is an example of such surprising behavior
- Most of the surprising behavior inherited from the old API is around
how
- At some point in the future we may fix bugs in these utilities inherited
from
system-filepath/system-fileio, but no decision either way has been made, yet
- Some old utilities are marked
DEPRECATEDif their behavior exactly matches the behavior of an existing utility from thefilepathordirectorypackage- These may be eventually removed at some point in the future or they remain in a deprecated state indefinitely. No decision either way has been made
- The
Turtlemodule also re-exports any utility suggested by aDEPRECATEDpragma as a convenience
- Other utilities are not deprecated if the old behavior significantly departs
from any existing utility from the
filepathordirectorypackage- For example, the behavior of the
filenameutility differs from the behavior ofSystem.FilePath.takeFileNamefor filenames that begin with a., so we have to preserve the old behavior to avoid breaking downstream code - At some point in the future utilities like these may be deprecated in
favor of their closest analogs in the
filepath/directorypackages or they may be supported indefinitely. No decision either way has been made
- For example, the behavior of the
- If you want to try to author code that is compatible with both the
pre-1.6 and post-1.6 API:
- If you add any instances to the
FilePathtype, import it qualified directly from thesystem-filepathpackage and use it only for instances - Otherwise, don’t import anything else from the
system-filepath/system-fileiopackages if you can help it. Instead, restrict yourself entirely to the utilities andFilePathtype exported by theTurtlemodule - Use the conversion utilities (e.g.
encodeStrings, even if they are not necessary post-1.6) - If that’s still not enough, use
CPPand good luck!
- If you add any instances to the
- This is a breaking change for a couple of reasons:
1.5.25
- Build against latest version of
Win32package
1.5.24
- Expose
Formatconstructor
1.5.23
- Add
fromIOutility - Build against GHC 9.0 / 9.2
1.5.22
- Add new
updateutility - Improve documentation for
limit
1.5.21
- Build against
optparse-applicative-0.16.0.0
1.5.20
- Build against
doctest-0.17 - Only depend on
semigroupsfor GHC < 8.0
1.5.19
- Add pattern synonyms for
Size
1.5.18
- Fix space leak
1.5.17
- Add
optionsExt: Extended version ofoptionswith header, footer, porgram-description and version information in--helpflag - Add
readlink
1.5.16
- Add
cptreeL
1.5.15
- Add
toLines - Add
Turtle.Bytes.{fromUTF8,toUTF8} - Add
Turtle.Bytes.{compress,decompress} - Always expose a
MonadFailinstance, relying on thefailpackage where needed. Related GHC 8.8 preparedness.
1.5.14
- Fix
cptreeto copy symlinks instead of descending into them - Build against newer versions of
Win32package
1.5.13
- Fix
chmodbug - Add
reduceand re-export(<&>)
1.5.12
- Increase upper bound on
containers
1.5.11
- Don’t forward broken pipe exceptions when using
inproc - Increase upper bound on
stm - Tutorial improvements:
1.5.10
- Increase upper bound on
doctestandcriterion
1.5.9
- Add
symlink
1.5.8
- Bug fix:
invertno longer rejects inputs where a prefix matches the inverted pattern - Add lsdepth, findtree, cmin, and cmax
- Increase upper bound on
temporaryandfoldl
1.5.7
- Increase upper bound on
doctest
1.5.6
- Increase upper bound on
exceptions
1.5.5
- Increase upper bound on
criterion
1.5.4
- Increase upper bound on
exceptions
1.5.3
- Increase upper bound on
doctest
1.5.2
- Increase upper bound on
async
1.5.1
- GHC 8.4 support
- Re-export
encodeString/decodeString - Update tutorial to use
stack script - Increase upper bounds on dependencies
1.5.0
- BREAKING CHANGE: Add
MonadCatchinstance forShell- This requires a breaking change to the internal implementation of
Shell - Most breaking changes can be fixed by replacing the
Shellconstructor with the newly added_Shellutility for ease of migration - If you don’t use the
Shellconstructor then this change likely does not affect you
- This requires a breaking change to the internal implementation of
- Add
eprintf
1.4.5
- Add
grepText,uniq,nub,sorttoTurtle.Prelude - Increase upper bound on
unix-compat
1.4.4
- Fix small mistake in tutorial
1.4.3
- Increase upper bound on
doctest
1.4.2
- Add
sed{Prefix,Suffix,Entire}andinplace{Prefix,Suffix,Entire}
1.4.1
- Increase upper bound on
doctest
1.4.0
- BREAKING CHANGE: Remove unnecessary
Maybefrom type ofsingle - BREAKING CHANGE: Consolidate
searchableandexecutable stream{,WithErr}now throws anExitCodeon failure
1.3.6
- Build against
ghc-8.2 - Relax upper bound on
optparse-applicativeandfoldl
1.3.5
- Increase upper bound on
foldl
1.3.4
- Bug fix:
cptreenow correctly copies files instead of creating directories of the same name - Increase upper bound on
criterion
1.3.3
- Bug fix: Change
textToLinesto behave likeData.Text.splitOn "\n"instead ofData.Text.unlines- This fixes weird behavior around handling empty strings.
splitOndoes the right thing, butunlinesdoes not. For example, this indirectly fixes a regression insed, which would discard empty lines
- This fixes weird behavior around handling empty strings.
- Bug fix:
which/whichAllnow behave correctly on Windows - Add new
cptree/singleutilities - Documentation fixes
1.3.2
- Fix bugs in subprocess management
- Generalize type of
reprto return any type that implementsIsString - Add
optLine,argLine, andlutilities to simplify working withLines
1.3.1
findno longer follows symlinks- Increase upper bound on
directory
1.3
- BREAKING CHANGE: Several utilities now produce and consume
Lines instead ofText- The purpose of this change is to fix a very common source of confusion for new users about which utilities are line-aware
- Most of the impact on existing code is just changing the types by
replacing
TextwithLinein the right places. The change at the term level should be small (based on the changes to the tutorial examples)
- BREAKING CHANGE:
Descriptionnow wraps aDocinstead ofText- In the most common case where users use string literals this has no effect
- New
Turtle.Bytesmodule that providesByteStringvariations on subprocess runners - Fix
dureporting incorrect sizes for directories - Add
pushd,stat,lstat,which,procStrictWithErr,shellStrictWithErr,onFiles,header,subcommandGroup, andparallel - Backport
needto GHC 7.6.3 - Fix missing help text for option parsers
- Fix bugs in subprocess management
1.2.8
- Increase upper bound on
timeandtransformers - Fix incorrect lower bound for
base
1.2.7
- Increase upper bound on
clockdependency
1.2.6
- Generalize several types to use
MonadManaged - Generalize type of
printfto useMonadIO - Add
system, andcopymod - Fix
rmtreeto more accurately match behavior ofrm -r
1.2.5
- Add
printf,utc,procs, andshells
1.2.4
- Generalize type of
dformat specifier to format anyIntegraltype - Add
inprocWithErr,inShellWithErr,inplace, andsz
1.2.3
- Add
subcommandandtestpath - Use line buffering for
Text-based subprocesses
1.2.2
- Re-export
with - Add
begins,ends,contains,lowerBounded,mktempfile,nl,pasteendless,lsif, andcut - Fix subprocess management bugs
1.2.1
- Fix subprocess management bugs
1.2.0
- BREAKING CHANGE:
dunow returns aSizeinstead of anInteger - New
Turtle.Optionsmodule that provides convenient utilities for options parsing - Add
hostname,outhandle,stderr,cache,countChars,countWords, andcountLines - Fix subprocess management bugs
1.1.1
- Add
bounded,upperBounded,procStrict,shellStrict,arguments - Add several
Permissions-related commands - Generalize several types to
MonadIO
1.1.0
- BREAKING CHANGE: Remove
Floating/Fractionalinstances forPatternandShell - BREAKING CHANGE: Change behavior of
Numinstance forPatternandShell - Re-export
(&) - Add
asciiCI,(.||.),(.&&.),strict
1.0.2
- Add
fpformat specifier - Add
chars/charshigh-efficiency parsing primitives - Fix bugs in path handling
1.0.1
- Generalize type of
die - Fix doctest
1.0.0
- Initial release