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Full Discussion: Incredibly inefficient cat | grep script
Top Forums Shell Programming and Scripting Incredibly inefficient cat | grep script Post 302913044 by achenle on Wednesday 13th of August 2014 01:01:35 PM
Old 08-13-2014
What's the exact contents of each file?

Right now, you're literally running millions of greps, comparing each ID to every other ID. That's a huge waste of time, obviously. You only really need to compare each ID to itself.

Because it seems to me that you're just looking for IDs that are in both files. If each ID only occurs once in each file, pull the IDs out of each file, combine them into one file, sort them, and only count IDs that are duplicated in the combined file.

Or you can figure out how to use the "join" utility, though that may not be any faster than what you're already doing, although it does have the huge advantage of not having to fork() and exec() a new process millions of times.
 

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LEARN ABOUT SUNOS

pthread_equal

pthread_equal(3C)														 pthread_equal(3C)

NAME

       pthread_equal - compare thread IDs

SYNOPSIS

       cc -mt [ flag... ] file... -lpthread [ library... ]
       #include <pthread.h>

       int pthread_equal(pthread_t t1, pthread_t t2);

       The pthread_equal() function compares the thread IDs t1 and t2.

       The pthread_equal() function returns a non-zero value if t1 and t2 are equal. Otherwise,  0 is returned.

       If  t1 or t2 is an invalid thread  ID, the behavior is undefined.

       No errors are defined.

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

       pthread_create(3C), pthread_self(3C), attributes(5), standards(5)

       Solaris thread IDs do not require an equivalent function because the thread_t structure is an unsigned int.

								    23 Mar 2005 						 pthread_equal(3C)
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