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Full Discussion: sed inside awk
Top Forums UNIX for Dummies Questions & Answers sed inside awk Post 302927238 by bakunin on Monday 1st of December 2014 04:26:13 PM
Old 12-01-2014
RudiC is correct, here is the long version about process substitution. It is a shell construct which works like that: "$( <command> )" is taken, then "command" is executed in a separate subshell and any output it produces is placed instead of the construct prior to evaluating the rest of the line it is part of, very similar to expanding a variable. The following two examples illustrate this and the similarity of the process (showing the steps in which the shell decodes the respective lines):

Code:
var="my text"
echo "$var"
   |
   V
echo my text
   |
   V
my text


Code:
echo $(echo "my text")
   +---> echo "my text"
   |        |
   |        V
   |     my text
   |        |
   | <------+
   |
   V
echo my text
   |
   V
my text

It is clear that such a syntactic device of the shell will not work outside the shell - like inside awk. For the same reasons PASCALs "BEGIN"-statements do not work in C and curly braces not in PASCAL.

Like RudiC rightfully said, awk can perform "global substitutions" (->gsub()) which do about the same as the "s/.../.../" (substitute) command in sed. It even uses the same regexps so the conversion of your sed statement should be pretty straightforward.

I hope this helps.

bakunin
This User Gave Thanks to bakunin For This Post:
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ECHO(1) 								FSF								   ECHO(1)

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