Groovy字符串执行与列表执行 [英] Groovy string execute versus list execute
问题描述
我希望这两个表达式在stdout不为空的情况下相同:
I expected both of these to behave the same in which stdout is not empty:
assert !"bash -c \"ls *.txt\"".execute().text.empty // assertion failure here
assert !['bash', '-c', 'ls *.txt'].execute().text.empty
但他们没有。什么是语义差异?对于第一行,我怀疑Groovy发送了 [ - c,\ls,* .txt \]
作为bash的参数,但是我不确定。任何人都可以证实这一点吗?
but they do not. What are the semantic differences? For the first line I suspect Groovy is sending ["-c", "\"ls", "*.txt\""]
as arguments to bash, but I'm not sure. Can anyone confirm that?
推荐答案
你的假设是正确的。请参阅thatt命令的返回码/ stderr:
Your assumption is correct. See the return code/stderr from thatt command:
groovy:000> p = "bash -c \"ls *.txt\"".execute()
===> java.lang.UNIXProcess@54eb2b70
groovy:000> p.waitFor() // exitValue()
===> 1
groovy:000> p.errorStream.readLines()
===> [*.txt": -c: line 0: unexpected EOF while looking for matching `"', *.txt": -c: line 1: syntax error: unexpected end of file]
If you follow the source down via https://github.com/apache/groovy/blob/GROOVY_2_4_8/src/main/org/codehaus/groovy/runtime/ProcessGroovyMethods.java#L532-L534 into the JDK's
java.lang。运行时:exec(String命令,String [] envp,File dir)
你会发现, StringTokenizer
用于sp点亮该字符串/命令,从而为您的引用无效的shell。所有引用只需要shell本身而不是
ProcessBuilder
。
you will find, that a StringTokenizer
is used to split that string/command, thus rendering your "
quoting for the shell useless. After all the quoting is only needed for the shell itself and not the ProcessBuilder
.
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