From: gwtmp01@...
Date: 2006-09-28T05:56:25+09:00
Subject: Re: how to determine if pipe is given


On Sep 27, 2006, at 4:42 PM, ara.t.howard@noaa.gov wrote:
> consider  i have many, many programs which do things like
>
>   convert infile outfile
>   convert - outfile       # infile on stdin
>   convert infile -        # outfile on stdout
>   convert - -             # infile on stdin, outfile on stdout
>   convert --infiles=-     # list of infiles on stdin, auto-name  
> outfiles

While I understand the historical reason for such constructs, I much  
prefer:

   convert infile outfile
   convert /dev/stdin outfile       # infile on stdin
   convert infile /dev/stdout       # outfile on stdout
   convert            		   # infile on stdin, outfile on stdout

>   convert --infiles=-    	 # list of infiles on stdin, auto-name  
> outfiles

Not sure about this last one.  It certainly isn't all that common.  
You can get close
to this via:

   cat filenames | xargs convert

with maybe an option to convert to cause it to send output to auto- 
named outfiles:

   cat filenames | xargs convert --inplace

I realize that some Unix systems don't support /dev/stdin, /dev/ 
stdout, though...


Gary Wright