# SystemExecute on consecutive records

**URL:** <https://forum.cloverdx.com/t/systemexecute-on-consecutive-records/1237>\
**Category:** CloverDX Platform\
**Created:** [July 1, 2013, 12:00am UTC](https://forum.cloverdx.com/t/systemexecute-on-consecutive-records/1237 "2013-07-01T00:00:00Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![p\_swiss](https://avatars.discourse-cdn.com/v4/letter/p/bc8723/32.png) [@p\_swiss](https://forum.cloverdx.com/u/p_swiss)\
**Post date:** [July 1, 2013, 12:00am UTC](https://forum.cloverdx.com/t/systemexecute-on-consecutive-records/1237/1 "2013-07-01T00:00:00Z")

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Hello,

I’m new to CloverETL, struggling to do the following: I have an input stream of multiple records, and I need to run a SystemExecute FOR EACH RECORD and generate an output based on that, where the System Command is a function of a string field of the corresponding input record. I tried to do this by connecting the reader to the input port of SystemExecute; however, this does not read consecutive input records… Any suggestions how I can do it?

Example of commands I want to run:

python myprogram.py arg1  
python myprogram.py arg2  
python myprogram.py arg3  
…

where arg1 arg2 arg3… are the values of a field of my input stream.

Thanks a lot!

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**Author:** ![imriskal](https://avatars.discourse-cdn.com/v4/letter/i/b38774/32.png) [@imriskal](https://forum.cloverdx.com/u/imriskal)\
**Post date:** [July 2, 2013, 11:38am UTC](https://forum.cloverdx.com/t/systemexecute-on-consecutive-records/1237/2 "2013-07-02T11:38:20Z")

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Hi, p\_swiss,

I think very similar problem is already solved here: [viewtopic.php?f=4&t=5241](http://forum.cloveretl.com/viewtopic.php?f=4&t=5241)

Please, take a look on it and let me know with any questions.

Best regards,

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<div class="post-metadata">

**Author:** ![p\_swiss](https://avatars.discourse-cdn.com/v4/letter/p/bc8723/32.png) [@p\_swiss](https://forum.cloverdx.com/u/p_swiss)\
**Post date:** [July 2, 2013, 2:46pm UTC](https://forum.cloverdx.com/t/systemexecute-on-consecutive-records/1237/3 "2013-07-02T14:46:56Z")

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Hi Lobus,

Thanks a lot for your reply. I had actually seen this post. In the solution I see it’s mentioned all input records are serialized and sent to SystemExecute as STDIN. But what I want is a different System Command to be executed for each record (the script depending on the field). Kind of a loop over the records… If I’m wrong, could you please explain in a bit more details how I can treat my example (arg1 arg2 arg3 … each for one different record). Sorry if I’m being a bit dummy here 🙂

Thanks!

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<div class="post-metadata">

**Author:** ![David\_Hlidek](https://avatars.discourse-cdn.com/v4/letter/d/58f4c7/32.png) [@David\_Hlidek](https://forum.cloverdx.com/u/David_Hlidek)\
**Post date:** [July 3, 2013, 11:15am UTC](https://forum.cloverdx.com/t/systemexecute-on-consecutive-records/1237/4 "2013-07-03T11:15:54Z")

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Hi p\_swiss,

You can use approach described in mentioned topic:

1. in loop parse lines out of whole stdin (line will be equal to one serialized record)  
2. if line/records contains more fields, parse them out (using fields delimiter used in metadata)

Inside of the loop use if-statements (using parsed fields in conditions) selecting proper commands to execute. Syntax of parsing&loop&if highly depends on your OS and used shell script interpreter.

Sample of stdin:

```auto

script1.py|42
script2.py|66

```

Parsed line:

```auto

script1.py|42

```

Parsed fields:

```auto

"script1.py" and "42"

```

I hope this helps.

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<div class="post-metadata">

**Author:** ![p\_swiss](https://avatars.discourse-cdn.com/v4/letter/p/bc8723/32.png) [@p\_swiss](https://forum.cloverdx.com/u/p_swiss)\
**Post date:** [July 3, 2013, 1:50pm UTC](https://forum.cloverdx.com/t/systemexecute-on-consecutive-records/1237/5 "2013-07-03T13:50:29Z")

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Thank you so much for your reply. I finally got how to do it with a loop in a shell script, works like charm 🙂

Thanks a lot!