ShellProcess
class ShellProcess : AutoCloseable
Represents a process that is running sh as a shell user.
Opposite to Shell this class doesn't handle the concept of command, rather it allows to read and write in the process streams, i.e. stdin, stdout, stderr. For example, using ShellProcess, it's possible to write a file in shell space like /data/local/tmp launching cp /dev/stdin /data/local/tmp/myfile:
ShellProcess.create().use {
// Writing a file
it.write("cp /dev/stdin /data/local/tmp/myfile")
it.stdin.write(myByteByffer)
// Reading a file
it.write("cat /data/local/tmp/somefile")
assert(it.stdout.bufferedReader().readLine() == "This is a test")
}
For the vast majority of commands used for testing, Shell process is a better candidate and automatically captures the full command output, as opposed to ShellProcess that doesn't distinguish where a command ends and another starts.
Note that this class is not thread safe due to internal state changes, although streams can be read or written by another thread, as long as it's always the same. For example it's possible to read ShellProcess.stdOut from another thread, as long as this doesn't change later.
ShellProcess should be used only when access to streams is required, like in the above example.
Summary
Public functions |
|
|---|---|
open Unit |
close()Closes the current process. |
Boolean |
isClosed()Returns whether the process is closed. |
Unit |
Writes a string in the process standard input. |
Public properties |
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|---|---|
InputStream |
An |
OutputStream |
An |
InputStream |
An |
Public functions
close
open fun close(): Unit
Closes the current process. Internally this simply sends the shell process the exit command. This means that the process is not immediately terminated, but gracefully shutdown finishing prior commands execution. Once a shell process is closed, further calls to close don't have any effect, as the stdIn will be closed after the first one.
writeLine
fun writeLine(string: String): Unit
Writes a string in the process standard input.
| Parameters | |
|---|---|
string: String |
a utf-8 string to write in the process stdin. |
Public properties
stdErr
val stdErr: InputStream
An InputStream for the process standard error. Note that this is backed by a tcp connection to the native cli utility. If a large output is expected but it's not important to capture it, a shell command may be launched piping in /dev/null.
For example:
cat large_file 2> /dev/null
stdIn
val stdIn: OutputStream
An OutputStream for the process standard output.
stdOut
val stdOut: InputStream
An InputStream for the process standard output. Note that this is backed by a tcp connection to the native cli utility. If a large output is expected but it's not important to capture it, a shell command may be launched piping in /dev/null.
For example:
cat large_file /dev/null