Starts the process represented by this builder, blocks until it exits, and returns the exit code. Standard output and error are sent to the given ProcessLogger.
Starts the process represented by this builder, blocks until it exits, and returns the exit code. Standard output and error are sent to the console.
Starts the process represented by this builder, blocks until it exits, and returns the output as a String. Standard error is sent to the provided ProcessLogger. If the exit code is non-zero, an exception is thrown.
Starts the process represented by this builder, blocks until it exits, and returns the output as a String. Standard error is sent to the console. If the exit code is non-zero, an exception is thrown.
Starts the process represented by this builder, blocks until it exits, and returns the output as a String. Standard error is sent to the provided ProcessLogger. If the exit code is non-zero, an exception is thrown. The newly started process reads from standard input of the current process.
Starts the process represented by this builder, blocks until it exits, and returns the output as a String. Standard error is sent to the console. If the exit code is non-zero, an exception is thrown. The newly started process reads from standard input of the current process.
Starts the process represented by this builder, blocks until it exits, and returns the exit code. Standard output and error are sent to the given ProcessLogger. The newly started process reads from standard input of the current process.
Starts the process represented by this builder, blocks until it exits, and returns the exit code. Standard output and error are sent to the console. The newly started process reads from standard input of the current process.
Constructs a command that will run this command and then other. The exit code will be the exit code of other.
Constructs a command that will run this command and pipes the output to other. other must be a simple command.
True if this command has an exit code which should be propagated to the user. Given a pipe between A and B, if B.hasExitValue is true then the exit code will be the one from B; if it is false, the one from A. This exists to prevent output redirections (implemented as pipes) from masking useful process error codes.
Starts the process represented by this builder. The output is returned as a LazyList that blocks when lines are not available but the process has not completed. The producer process will block if the given capacity of lines if filled without being consumed from the LazyList. Standard error is sent to the provided ProcessLogger. If the process exits with a non-zero value, the LazyList will provide all lines up to termination and then throw an exception.
Starts the process represented by this builder. The output is returned as a LazyList that blocks when lines are not available but the process has not completed. Standard error is sent to the provided ProcessLogger. If the process exits with a non-zero value, the LazyList will provide all lines up to termination and then throw an exception.
Starts the process represented by this builder. The output is returned as a LazyList that blocks when lines are not available but the process has not completed. The producer process will block if the given capacity of lines if filled without being consumed from the LazyList. Standard error is sent to the console. If the process exits with a non-zero value, the LazyList will provide all lines up to termination and then throw an exception.
Starts the process represented by this builder. The output is returned as a LazyList that blocks when lines are not available but the process has not completed. Standard error is sent to the console. If the process exits with a non-zero value, the LazyList will provide all lines up to termination and then throw an exception.
Starts the process represented by this builder. The output is returned as a LazyList that blocks when lines are not available but the process has not completed. The producer process will block if the given capacity of lines if filled without being consumed from the stream. Standard error is sent to the provided ProcessLogger. If the process exits with a non-zero value, the LazyList will provide all lines up to termination but will not throw an exception.
Starts the process represented by this builder. The output is returned as a LazyList that blocks when lines are not available but the process has not completed. Standard error is sent to the provided ProcessLogger. If the process exits with a non-zero value, the LazyList will provide all lines up to termination but will not throw an exception.
Starts the process represented by this builder. The output is returned as a LazyList that blocks when lines are not available but the process has not completed. The producer process will block if the given capacity of lines if filled without being consumed from the stream. Standard error is sent to the console. If the process exits with a non-zero value, the LazyList will provide all lines up to termination but will not throw an exception.
Starts the process represented by this builder. The output is returned as a LazyList that blocks when lines are not available but the process has not completed. Standard error is sent to the console. If the process exits with a non-zero value, the LazyList will provide all lines up to termination but will not throw an exception.
Starts the process represented by this builder. Standard output and error are sent to the given ProcessLogger. The newly started process reads from standard input of the current process if connectInput is true.
Starts the process represented by this builder. Standard output and error are sent to the console. The newly started process reads from standard input of the current process if connectInput is true.
Starts the process represented by this builder. I/O is handled by the given ProcessIO instance.
Starts the process represented by this builder. Standard output and error are sent to the given ProcessLogger.
Starts the process represented by this builder. Standard output and error are sent to the console.
Starts the process represented by this builder. The output is returned as a Stream that blocks when lines are not available but the process has not completed. The producer process will block if the given capacity of lines if filled without being consumed from the stream. Standard error is sent to the provided ProcessLogger. If the process exits with a non-zero value, the Stream will provide all lines up to termination and then throw an exception.
(Since version 2.13.0) use lazyLines
Starts the process represented by this builder. The output is returned as a Stream that blocks when lines are not available but the process has not completed. Standard error is sent to the provided ProcessLogger. If the process exits with a non-zero value, the Stream will provide all lines up to termination and then throw an exception.
(Since version 2.13.0) use lazyLines
Starts the process represented by this builder. The output is returned as a Stream that blocks when lines are not available but the process has not completed. The producer process will block if the given capacity of lines if filled without being consumed from the stream. Standard error is sent to the console. If the process exits with a non-zero value, the Stream will provide all lines up to termination and then throw an exception.
(Since version 2.13.0) use lazyLines
Starts the process represented by this builder. The output is returned as a Stream that blocks when lines are not available but the process has not completed. Standard error is sent to the console. If the process exits with a non-zero value, the Stream will provide all lines up to termination and then throw an exception.
(Since version 2.13.0) use lazyLines
Starts the process represented by this builder. The output is returned as a Stream that blocks when lines are not available but the process has not completed. The producer process will block if the given capacity of lines if filled without being consumed from the stream. Standard error is sent to the provided ProcessLogger. If the process exits with a non-zero value, the Stream will provide all lines up to termination but will not throw an exception.
(Since version 2.13.0) use lazyLines_!
Starts the process represented by this builder. The output is returned as a Stream that blocks when lines are not available but the process has not completed. Standard error is sent to the provided ProcessLogger. If the process exits with a non-zero value, the Stream will provide all lines up to termination but will not throw an exception.
(Since version 2.13.0) use lazyLines_!
Starts the process represented by this builder. The output is returned as a Stream that blocks when lines are not available but the process has not completed. The producer process will block if the given capacity of lines if filled without being consumed from the stream. Standard error is sent to the console. If the process exits with a non-zero value, the Stream will provide all lines up to termination but will not throw an exception.
(Since version 2.13.0) use lazyLines_!
Starts the process represented by this builder. The output is returned as a Stream that blocks when lines are not available but the process has not completed. Standard error is sent to the console. If the process exits with a non-zero value, the Stream will provide all lines up to termination but will not throw an exception.
(Since version 2.13.0) use lazyLines_!
Test two objects for inequality.
true if !(this == that), false otherwise.
Equivalent to x.hashCode except for boxed numeric types and null. For numerics, it returns a hash value which is consistent with value equality: if two value type instances compare as true, then ## will produce the same hash value for each of them. For null returns a hashcode where null.hashCode throws a NullPointerException.
a hash value consistent with ==
Reads the output of a scala.sys.process.ProcessBuilder into the input stream of this process.
Reads the given InputStream into the input stream of this process. The argument is call-by-name, so the stream is recreated, read, and closed each time this process is executed.
Reads the given URL into the input stream of this process.
Reads the given file into the input stream of this process.
Writes the output stream of this process to a scala.sys.process.ProcessBuilder.
Writes the output stream of this process to the given OutputStream. The argument is call-by-name, so the stream is recreated, written, and closed each time this process is executed.
Writes the output stream of this process to the given file.
Appends the output stream of this process to the given file.
The expression x == that is equivalent to if (x eq null) that eq null else x.equals(that).
true if the receiver object is equivalent to the argument; false otherwise.
Cast the receiver object to be of type T0.
Note that the success of a cast at runtime is modulo Scala's erasure semantics. Therefore the expression 1.asInstanceOf[String] will throw a ClassCastException at runtime, while the expression List(1).asInstanceOf[List[String]] will not. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the requested type.
the receiver object.
ClassCastException if the receiver object is not an instance of the erasure of type T0.
Returns a scala.sys.process.ProcessBuilder representing this Source.
Create a copy of the receiver object.
The default implementation of the clone method is platform dependent.
a copy of the receiver object.
Tests whether the argument (that) is a reference to the receiver object (this).
The eq method implements an equivalence relation on non-null instances of AnyRef, and has three additional properties:
x and y of type AnyRef, multiple invocations of x.eq(y) consistently returns true or consistently returns false.For any non-null instance x of type AnyRef, x.eq(null) and null.eq(x) returns false.
null.eq(null) returns true. When overriding the equals or hashCode methods, it is important to ensure that their behavior is consistent with reference equality. Therefore, if two objects are references to each other (o1 eq o2), they should be equal to each other (o1 == o2) and they should hash to the same value (o1.hashCode == o2.hashCode).
true if the argument is a reference to the receiver object; false otherwise.
The equality method for reference types. Default implementation delegates to eq.
See also equals in scala.Any.
true if the receiver object is equivalent to the argument; false otherwise.
Called by the garbage collector on the receiver object when there are no more references to the object.
The details of when and if the finalize method is invoked, as well as the interaction between finalize and non-local returns and exceptions, are all platform dependent.
Returns string formatted according to given format string. Format strings are as for String.format (@see java.lang.String.format).
Returns the runtime class representation of the object.
a class object corresponding to the runtime type of the receiver.
The hashCode method for reference types. See hashCode in scala.Any.
the hash code value for this object.
Test whether the dynamic type of the receiver object is T0.
Note that the result of the test is modulo Scala's erasure semantics. Therefore the expression 1.isInstanceOf[String] will return false, while the expression List(1).isInstanceOf[List[String]] will return true. In the latter example, because the type argument is erased as part of compilation it is not possible to check whether the contents of the list are of the specified type.
true if the receiver object is an instance of erasure of type T0; false otherwise.
Equivalent to !(this eq that).
true if the argument is not a reference to the receiver object; false otherwise.
Wakes up a single thread that is waiting on the receiver object's monitor.
not specified by SLS as a member of AnyRef
Wakes up all threads that are waiting on the receiver object's monitor.
not specified by SLS as a member of AnyRef
Creates a String representation of this object. The default representation is platform dependent. On the java platform it is the concatenation of the class name, "@", and the object's hashcode in hexadecimal.
a String representation of the object.
© 2002-2019 EPFL, with contributions from Lightbend.
Licensed under the Apache License, Version 2.0.
https://www.scala-lang.org/api/2.13.0/scala/sys/process/ProcessBuilder.html
Represents a sequence of one or more external processes that can be executed. A
ProcessBuildercan be a single external process, or a combination of otherProcessBuilder. One can control where the output of an external process will go to, and where its input will come from, or leave that decision to whoever starts it.One creates a
ProcessBuilderthrough factories provided in scala.sys.process.Process's companion object, or implicit conversions based on these factories made available in the package object scala.sys.process. Here are some examples:import scala.sys.process._ // Executes "ls" and sends output to stdout "ls".! // Execute "ls" and assign a `LazyList[String]` of its output to "contents". val contents = Process("ls").lazyLines // Here we use a `Seq` to make the parameter whitespace-safe def contentsOf(dir: String): String = Seq("ls", dir).!!The methods of
ProcessBuilderare divided in three categories: the ones that combine twoProcessBuilderto create a third, the ones that redirect input or output of aProcessBuilder, and the ones that execute the external processes associated with it.Combining
ProcessBuilderTwo existing
ProcessBuildercan be combined in the following ways:#|method.###method.#&&and#||accomplish these tasks.Redirecting Input/Output
Though control of input and output can be done when executing the process, there's a few methods that create a new
ProcessBuilderwith a pre-configured input or output. They are#<,#>and#>>, and may take as input either anotherProcessBuilder(like the pipe described above), or something else such as ajava.io.Fileor ajava.io.InputStream. For example:new URL("http://databinder.net/dispatch/About") #> "grep JSON" #>> new File("About_JSON") !Starting Processes
To execute all external commands associated with a
ProcessBuilder, one may use one of four groups of methods. Each of these methods have various overloads and variations to enable further control over the I/O. These methods are:run: the most general method, it returns a scala.sys.process.Process immediately, and the external command executes concurrently.!: blocks until all external commands exit, and returns the exit code of the last one in the chain of execution.!!: blocks until all external commands exit, and returns aStringwith the output generated.lazyLines: returns immediately likerun, and the output being generated is provided through aLazyList[String]. Getting the next element of thatLazyListmay block until it becomes available. This method will throw an exception if the return code is different than zero -- if this is not desired, use thelazyLines_!method.Handling Input and Output
If not specified, the input of the external commands executed with
runor!will not be tied to anything, and the output will be redirected to the stdout and stderr of the Scala process. For the methods!!andlazyLines, no input will be provided, and the output will be directed according to the semantics of these methods.Some methods will cause stdin to be used as input. Output can be controlled with a scala.sys.process.ProcessLogger --
!!andlazyLineswill only redirect error output when passed aProcessLogger. If one desires full control over input and output, then a scala.sys.process.ProcessIO can be used withrun.For example, we could silence the error output from
lazyLines_!like this:Extended Example
Let's examine in detail one example of usage:
import scala.sys.process._ "find src -name *.scala -exec grep null {} ;" #| "xargs test -z" #&& "echo null-free" #|| "echo null detected" !Note that every
Stringis implicitly converted into aProcessBuilderthrough the implicits imported from scala.sys.process. TheseProcessBuilderare then combined in three different ways.#|pipes the output of the first command into the input of the second command. It mirrors a shell pipe (|).#&&conditionally executes the second command if the previous one finished with exit value 0. It mirrors shell's&&.#||conditionally executes the third command if the exit value of the previous command is different than zero. It mirrors shell's||.Finally,
!at the end executes the commands, and returns the exit value. Whatever is printed will be sent to the Scala process standard output. If we wanted to capture it, we could run that with!!instead.Note: though it is not shown above, the equivalent of a shell's
;would be###. The reason for this name is that;is a reserved token in Scala.