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Full Discussion: UNIX fifo concurrent read from a named pipe
Top Forums Shell Programming and Scripting UNIX fifo concurrent read from a named pipe Post 303013481 by naveen mani on Thursday 22nd of February 2018 03:39:16 AM
Old 02-22-2018
Wrench UNIX fifo concurrent read from a named pipe
I have created a fifo named pipe in solaris, which writes the content of a file, line by line, into pipe as below:
Code:
$ mkfifo namepipe

$ cat books.txt
"how to write unix code"
"how to write oracle code"

$ cat books.txt >> namepipe &

I have a readpipe.sh script which reads the named pipe in parallel like this:
Code:
# readpipe.sh

while IFS=',' read var
do
  echo var >> log.txt

done < namepipe

I am calling the readpipe.sh like
Code:
readpipe.sh &
sleep 2
readpipe.sh &

I have introduced a sleep 2 to avoid a race condition to occur, i.e. two processes get parts of values from each line

The problem I am facing is when the all the contents of namepipe is completed, the first background process gets exited, while the second keeps on running without completing.

The logic in script is declared simple in here for clear understanding. Actual readpipd.sh does lots of activities.

Kindly help me with knowledge
 

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LEARN ABOUT MOJAVE

locale::codes::script

Locale::Codes::Script(3pm)				 Perl Programmers Reference Guide				Locale::Codes::Script(3pm)

NAME

       Locale::Codes::Script - standard codes for script identification

SYNOPSIS

	  use Locale::Codes::Script;

	  $script  = code2script('phnx');		      # 'Phoenician'
	  $code    = script2code('Phoenician'); 	      # 'Phnx'
	  $code    = script2code('Phoenician',
				 LOCALE_CODE_NUMERIC);	      # 115

	  @codes   = all_script_codes();
	  @scripts = all_script_names();

DESCRIPTION

       The "Locale::Codes::Script" module provides access to standards codes used for identifying scripts, such as those defined in ISO 15924.

       Most of the routines take an optional additional argument which specifies the code set to use. If not specified, the default ISO 15924
       four-letter codes will be used.

SUPPORTED CODE SETS

       There are several different code sets you can use for identifying scripts. A code set may be specified using either a name, or a constant
       that is automatically exported by this module.

       For example, the two are equivalent:

	  $script = code2script('phnx','alpha');
	  $script = code2script('phnx',LOCALE_SCRIPT_ALPHA);

       The codesets currently supported are:

       alpha, LOCALE_SCRIPT_ALPHA
	   This is a set of four-letter (capitalized) codes from ISO 15924 such as 'Phnx' for Phoenician.  It also includes additions to this set
	   included in the IANA language registry.

	   The Zxxx, Zyyy, and Zzzz codes are not used.

	   This is the default code set.

       num, LOCALE_SCRIPT_NUMERIC
	   This is a set of three-digit numeric codes from ISO 15924 such as 115 for Phoenician.

ROUTINES

       code2script ( CODE [,CODESET] )
       script2code ( NAME [,CODESET] )
       script_code2code ( CODE ,CODESET ,CODESET2 )
       all_script_codes ( [CODESET] )
       all_script_names ( [CODESET] )
       Locale::Codes::Script::rename_script  ( CODE ,NEW_NAME [,CODESET] )
       Locale::Codes::Script::add_script  ( CODE ,NAME [,CODESET] )
       Locale::Codes::Script::delete_script  ( CODE [,CODESET] )
       Locale::Codes::Script::add_script_alias	( NAME ,NEW_NAME )
       Locale::Codes::Script::delete_script_alias  ( NAME )
       Locale::Codes::Script::rename_script_code  ( CODE ,NEW_CODE [,CODESET] )
       Locale::Codes::Script::add_script_code_alias  ( CODE ,NEW_CODE [,CODESET] )
       Locale::Codes::Script::delete_script_code_alias	( CODE [,CODESET] )
	   These routines are all documented in the Locale::Codes::API man page.

SEE ALSO

       Locale::Codes
	   The Locale-Codes distribution.

       Locale::Codes::API
	   The list of functions supported by this module.

       http://www.unicode.org/iso15924/
	   Home page for ISO 15924.

       http://www.iana.org/assignments/language-subtag-registry
	   The IANA language subtag registry.

AUTHOR

       See Locale::Codes for full author history.

       Currently maintained by Sullivan Beck (sbeck@cpan.org).

COPYRIGHT

	  Copyright (c) 1997-2001 Canon Research Centre Europe (CRE).
	  Copyright (c) 2001-2010 Neil Bowers
	  Copyright (c) 2010-2013 Sullivan Beck

       This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

perl v5.18.2							    2013-11-04						Locale::Codes::Script(3pm)
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