SimpleCmd

Some simple String wrappers of readProcess, readProcessWithExitCode, rawSystem from the Haskell process library.

Simplest is

cmd_ :: String -> [String] -> IO ()

which outputs to stdout. For example:

cmd_ "git" ["clone", url]

Then

cmd :: String -> [String] -> IO String

returns stdout as a String.

There are also cmdBool, cmdMaybe, cmdLines, shell, and others.

Other examples:

grep_ pat file :: IO Bool

sudo c args :: IO ()

Documentation

cmd

Arguments

:: String

command to run

-> [String]

list of arguments

-> IO String

stdout

cmd c args runs a command in a process and returns stdout

cmd_ :: String -> [String] -> IO ()

cmd_ c args runs command in a process, output goes to stdout and stderr

cmdBool :: String -> [String] -> IO Bool

cmdBool c args runs a command, and return Boolean status

cmdIgnoreErr :: String -> [String] -> String -> IO String

cmdIgnoreErr c args inp runs a command with input, drops stderr, and return stdout

cmdLines :: String -> [String] -> IO [String]

cmdLines c args runs a command, and returns list of stdout lines

Since: 0.1.1

cmdMaybe :: String -> [String] -> IO (Maybe String)

cmdMaybe c args runs a command, maybe returning output if it succeeds

cmdFull :: String -> [String] -> String -> IO (Bool, String, String)

cmdFull c args inp runs readProcessWithExitCode and converts the ExitCode to Bool Removes the last newline from stdout and stderr (like the other functions)

cmdLog :: String -> [String] -> IO ()

cmdLog c args logs a command with a datestamp

Since: 0.1.4

cmdlog :: String -> [String] -> IO ()

cmdlog deprecated alias for cmdLog (will be removed in 0.3)

cmdN :: String -> [String] -> IO ()

cmdN c args dry-runs a command: prints command to stdout - more used for debugging

cmdQuiet :: String -> [String] -> IO String

cmdQuiet c args runs a command hiding stderr, if it succeeds returns stdout

cmdSilent :: String -> [String] -> IO ()

cmdSilent c args runs a command hiding stdout: stderr is only output if it fails.

cmdStdIn :: String -> [String] -> String -> IO String

cmdStdIn c args inp runs a command, passing input string as stdin, and returns stdout

cmdStdErr :: String -> [String] -> IO (String, String)

cmdStdErr c args runs command in a process, returning stdout and stderr

cmdTry_ :: String -> [String] -> IO ()

cmdTry_ c args runs the command if available

Since: 0.2.1

cmdStderrToStdout :: String -> [String] -> IO (ExitCode, String)

Redirect stderr to stdout, ie with interleaved output

Since: 0.2.2

cmdStderrToStdoutIn :: String -> [String] -> String -> IO (Bool, String)

Redirect stderr to stdout, ie with interleaved output

Since: 0.2.3

needProgram :: String -> IO ()

Assert program in PATH

needProgram progname

Since: 0.2.1

error' :: String -> a

Alias for errorWithoutStackTrace (for base >= 4.9)

Since: 0.1.4

warning :: String -> IO ()

warning outputs to stderr

Since: 0.2.0

logMsg :: String -> IO ()

logMsg msg outputs message with a timestamp

(+-+) :: String -> String -> String infixr 4

Combine two strings with a single space

removePrefix :: String -> String -> String

removePrefix prefix original removes prefix from string if present

removeStrictPrefix :: String -> String -> String

removeStrictPrefix prefix original removes prefix, or fails with error'

removeSuffix :: String -> String -> String

removeSuffix suffix original removes suffix from string if present

egrep_ :: String -> FilePath -> IO Bool

egrep_ pat file greps extended regexp in file, and returns Boolean status

grep :: String -> FilePath -> IO [String]

grep pat file greps pattern in file, and returns list of matches

@since 0.1.2 (fixed not to error in 0.2.2)

grep_

Arguments

:: String

pattern

-> FilePath

file

-> IO Bool

result

grep_ pat file greps pattern in file and returns Boolean status

shell :: String -> IO String

shell cs runs a command string in a shell, and returns stdout

shell_ :: String -> IO ()

shell_ cs runs a command string in a shell, output goes to stdout

shellBool :: String -> IO Bool

shellBool cs runs a command string in a shell, output goes to stdout

Since: 0.2.0

sudo

Arguments

:: String

command

-> [String]

arguments

-> IO String

sudo c args runs a command as sudo returning stdout

Result type changed from IO () to IO String in 0.2.0

sudo_

Arguments

:: String

command

-> [String]

arguments

-> IO ()

sudo_ c args runs a command as sudo

Since: 0.2.0

type PipeCommand = (String, [String])

Type alias for a command in a pipe

Since: 0.2.0

pipe :: PipeCommand -> PipeCommand -> IO String

Return stdout from piping the output of one process to another

Since: 0.2.0

pipe_ :: PipeCommand -> PipeCommand -> IO ()

Pipe two commands without returning anything

Since: 0.2.0

pipeBool :: PipeCommand -> PipeCommand -> IO Bool

Bool result of piping of commands @since 0.2.0 Returns False if either command fails (since 0.2.4).

pipe3 :: PipeCommand -> PipeCommand -> PipeCommand -> IO String

Pipe 3 commands, returning stdout

Since: 0.2.3

pipe3_ :: PipeCommand -> PipeCommand -> PipeCommand -> IO ()

Pipe 3 commands, not returning anything

Since: 0.2.0

pipeFile_ :: FilePath -> PipeCommand -> PipeCommand -> IO ()

Pipe a file to the first of a pipe of commands

Since: 0.2.0

ifM :: Monad m => m Bool -> m a -> m a -> m a

Like if, but where the test can be monadic.

whenM :: Monad m => m Bool -> m () -> m ()

Like when, but where the test can be monadic.

filesWithExtension :: FilePath -> String -> IO [FilePath]

returns the files with the give extension

fileWithExtension :: FilePath -> String -> IO (Maybe FilePath)

timeIO :: IO a -> IO a

Run an IO action and then print how long it took