bash - How can I split and re-join STDOUT from multiple processes? -


I am working on a pipeline that has some branch points that merge later - they do something like this Looks like: 

  command2 / \ command1 command4 \ command3   
 each command writes STDOUT and accepts input through STDIN is. Command1 to STDOUT  both  command2 and command3, which are run  sequentially , need to be passed, and their outputs are effectively communicated. Need to go and pass in Command 4. I initially thought that something like this would work:  
  $ command1 | (Command2; Command3). Command4   
 This does not work, because only the STDOUT is sent to 4 commands from Command2, and when I remove Command4, it is clear that Command3 In other words, it seems that the command2 is tired or is consuming the stream - not passing the proper stream from Command1 -. I have the same result {command2; Command3; } In the middle then I thought I should use, and tried to do this:  
  $ command1 | T & gt; (Command2). Command3 | Command4   
 But surprisingly it also does not work - it appears that Command1  and  the command 2 is piped in Command3 , Resulting in errors and Command3 only pipe into command 4. I have found that the following input and output are given from Command2 and Command3:  
  $ command1 | T & gt; (Command2) & gt; (Command3). Command4   
 However, the output of Command1 is also lowered with Command4, which produces different specifications compared to Command1 and Command3. is. The solution I received is hack, but it works:  
  $ command1 | T & gt; (Command2) & gt; (Command3) & gt; / Dev / null | Command4   
 It outputs command1 to command 4, whereas the command2 collects STDOS with command and command3. It works, but I think I am not getting a more clear solution, am I? I have read dozens of threads and have not solved this problem which works in my use, nor have I seen the exact problem of splitting and re-connecting currents (although I can not be the first one to be a To deal with) Should I just use the named pipes? I tried, but it also had difficulty working, so maybe it is another story for another thread. I am using Bash in RHEL 5.8.   
 
 
 You can play with file descriptors like this;  
  ((date | t> (wc & gt; and 3) | wc) 3 & gt; and 1). WC   
 or  
  ((command1 | tee> (command2 & gt; and 3) | order3) 3 & gt; and 1 ). Command4   
 To explain this, it will output the original data to  tee> (wc & amp; 3)  stdout, and the internal  Wc  results will output to FD3. External 3 & gt; & Amp; 1) Then the FD3 will bring the output back to STDOUT, so the output tailing command from both wc is sent.  
 However, there is nothing in this pipeline (or one of its own solutions) that will guarantee that production will not be disturbed. The imperfect lines from Command2 will not be mixed with the command 3 - if this is a concern, then you have to do one of the two things;  
     
  1.  Write your own   
  2.  Type the file into a file with a command2 and command 3 and use  cat      > To merge data as input in command 4

Comments

Post a Comment

Popular posts from this blog

Java - Error: no suitable method found for add(int, java.lang.String) -

I'm in the middle of homework work and I'm stuck. At this point in my code, I think that I should have a GUI window that opens and allows me to type "inserted text number". Notice is not going anywhere but at this point, If I pass through the problem then it will be in a linked list. I am getting two of the same error for the lines. Add (index, element); And I can not seem to get past it, there is no suitable method for the error "add (int, java. string string)". Code is below, please advise. To clarify - this will not be a method error because it is a linked list. There should not be any way involved. import java.awt. *; Import java.awt.event. *; Import javax.swing. *; Import java.util. *; Import java.util.Scanner; Import java.util.LinkedList; Public class TopTenList JFrame {Private TopTenList tt; See the Private JTextArea list; Private JTextField cmdTextField; Private JTextField resultsTestfield; // This GUI window is the code for the public toptist...
Read more

java - JPA TypedQuery: Parameter value element did not match expected type -

I am using JPA 2.0 and getting the following code in the DAO layer: Public Zero Test () {string key = "status"; String [] Conditions = {"A", "B"}; & Lt; TestTable & gt; Results = Search (Keys, Conditions); } Public listing & lt; TestTable & gt; Search (string key, object value error) {string sql = "test ndf to testlet and jade nand." + Key + "in:" + key; TypedQuery & LT; TestTable & gt; Query = entityManager.createQuery (SQL, TestTable.class); Query.setParameter (key, Arrays.asList (valueArr)) / *** Error Line *** Return query.getResultList (); } In the above error line, it throws the following exception: java.lang.IllegalArgumentException: parameter value element [[Ljava.lang.String; @ cbe5bc] did not match the expected type [java.lang.String] Why is this expected type string while actually this string []? Please help! Note: This is derived from the normal routine and is a simplified code. I can no...
Read more

c++ - static template member variable has internal linkage but is not defined -

Yes, I know, there is a question with almost the same title, but it refers to a different situation. Error message) In my case, I have a .cpp file with a big named designation name (implementation details). There is a property class template with a static data member in that name space, which I need to access from outside the unknown namespace. I give it a little bit of meat: file.hpp namespace Bar {template & lt; Typename A & gt; Struct foo {static_assert (is_same & lt; a, float & gt; :: value} is_same & lt; a, double>: value, ""); Fixed zero set_static_var (a const & x); // ...}; } and file.cpp namespace {template & lt; Typename A & gt; Struct foo_traits {// supports the implementation of several static code bars: foo & lt; & Gt; Fixed A data; }; The template's & lt; & Gt; Float foo_traits & lt; Float & gt; :: datum; // No change if this is in the global namespace template & lt; & Gt; Doub...
Read more