java - 在 Linux 中使用重定向时如何使用 ProcessBuilder

Question

我想使用 ProcessBuilder 运行此命令:

sort -m -u -T /dir -o output <(zcat big-zipped-file1.gz | sort -u) <(zcat big-zipped-file2.gz | sort -u) <(zcat big-zipped-file3.gz | sort -u) 

我尝试了以下方法:

// This doesn't recognise the redirection.
String[] args = new String[] {"sort", "-m", "-u", "-T", "/dir", "-o", "output", "<(zcat big-zipped-file1.gz | sort -u)", "<(zcat big-zipped-file2.gz | sort -u)", "<(zcat big-zipped-file3.gz | sort -u)"};

// This gives:
// /bin/sh: -c: line 0: syntax error near unexpected token `('
String[] args = new String[] {"/bin/sh", "-c", "\"sort -m -u -T /dir -o output <(zcat big-zipped-file1.gz | sort -u) <(zcat big-zipped-file2.gz | sort -u) <(zcat big-zipped-file3.gz | sort -u)\""};

我正在像这样使用 args:processBuilder.command(args);

Answer 1

我终于明白了。正如 Roman 在他的评论中提到的，sh 不理解重定向，所以我不得不使用 bash。我还必须同时使用输入流和错误流。

String[] args = new String[] {"/bin/bash", "-c", "sort -m -u -T /dir -o output <(zcat big-zipped-file1.gz | sort -u) <(zcat big-zipped-file2.gz | sort -u) <(zcat big-zipped-file3.gz | sort -u)"};

ProcessBuilder builder = new ProcessBuilder();
builder.command(args);
Process process = builder.start();
BufferedReader input = new BufferedReader(new InputStreamReader(process.getInputStream()));
BufferedReader error = new BufferedReader(new InputStreamReader(process.getErrorStream()));
while((line = input.readLine()) != null);
while((line = error.readLine()) != null);

process.waitFor();