HP OpenVMS Systems

DIFFERENCES statistics, without output?

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The Question is:

 
How can I make DCL DIFFERENCE output only statistics (just like DCL SEARCH
 /WIN=0 or DCL DIR /NOHEAD/NOTRAIL) and not also the actual differences?
(We are using a commandprocedure which attempts to fill the void left by DIFF
 not supporting wildcards by invoking DIFF for each file returned by
 F$SEARCH(). Whenever DIFF encounters a non-ascii file - like an executable -
 then the output of DIFF tends to
 change the terminal settings because the terminal interprets the DIFF output
 as control characters - I think. Just knowing that differences exist would
 suffice for us with these files. Is it correct to test for whether a file is
 an ASCII file or not usin
g the following expression
f$file(file,"RFM") .eqs. "FIX" .or. f$file(file,"RAT") .eqs. "RAT"?
Thank you very much.
 

The Answer is :

One option is to check the status returned from the DIFFERENCES command, like
this:
 
	$ DIFFER/OUTPUT=NL: file1.ext file2.ext
	$ IF $STATUS .EQ. %X006C8009 THEN $ GOTO NO_DIFFERENCE
 
or
	$ IF $STATUS .EQ. %X006C8013 THEN $ GOTO THERE_IS_A_DIFFERENECE
 
A little experimentation with different combinations of input files and the
resulting $STATUS values should enable you do do what you want.
 
(Note:  the /NOOUTPUT qualifier does not supress output from DIFFERENCES!
That's why you have to use /OUTPUT=NL:)

  

     

     
answer written or last revised on ( 5-MAY-2000 )
     
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