groovy - 使用 Groovy 获取进程的 PID

Question

我正在尝试在 Groovy 中创建一个方法来获取应用程序的进程 ID。我目前处于这个阶段:

String getProcessIdFor(String program) {
    def buffer = new StringBuffer()

    Process commandOne = 'ps -A'.execute()
    Process commandTwo = "grep -m1 '${program}'".execute()
    Process commandThree = "awk '{print \$1}'".execute()

    Process process = commandOne | commandTwo | commandThree
    process.waitForProcessOutput(buffer, buffer)

    return buffer.toString()
}

但这给了我:

Exception in thread "Thread-1" groovy.lang.GroovyRuntimeException: exception while reading process stream
awk: syntax error at source line 1
at org.codehaus.groovy.runtime.ProcessGroovyMethods$3.run(ProcessGroovyMethods.java:402)
context is
at java.lang.Thread.run(Thread.java:745)
 >>> ' <<< 
missing }
Caused by: java.io.IOException: Stream closed
awk: bailing out at source line 1
at java.lang.ProcessBuilder$NullOutputStream.write(ProcessBuilder.java:434)
at java.io.OutputStream.write(OutputStream.java:116)
at java.io.BufferedOutputStream.write(BufferedOutputStream.java:122)
at java.io.BufferedOutputStream.write(BufferedOutputStream.java:122)
at org.codehaus.groovy.runtime.ProcessGroovyMethods$3.run(ProcessGroovyMethods.java:399)
... 1 more

Process finished with exit code 0

看来是在 awk上苦苦挣扎命令，但我似乎无法弄清楚我哪里出错了。有任何想法吗？

Answer 1

另一种选择(因为 ps 的输出不应该阻塞任何缓冲区)

Integer getPid(processName) {
    'ps -A'.execute()
           .text
           .split('\n')
           .find { it.contains processName }?.split()?.first() as Integer
}

println getPid('groovyconsole')