filename: awkslurp.txt
  author: Eric Pement
    date: March 26, 2003

How to slurp up whole files in awk
==================================

To slurp up an entire file at once in awk, set the RS (record 
separator) variable to an unused character that is not in the file. 
E.g.,

   BEGIN { RS = "\f" }       # \f is formfeed or Ctrl-L

However, if you plan to pass multiple files on the command-line to 
awk, like this:

   awk -f myscript.awk file*

   awk 'BEGIN{RS="\f"}; {more-to-come...}' file*

you may also need a way to cycle through each file one at a time. It 
is NOT possible to use the END{...} block in awk, since the END{...} 
block is invoked only once, after all the files have been read. 
Therefore, a different technique must be used.

If reading whole files, use the FNR variable, which is like NR (number 
of the current record) relative to the current file. Thus, when FNR==1 
in slurp mode, you know that the entire file has been read. Thus, here 
is an example:

   BEGIN{ RS = "\f" }
   FNR==1 && /foo.*bar/ { print "Both terms occur in " FILENAME }

which can be invoked like this:

   awk -f myscript.awk file*


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