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wiki:awksintax [2017/12/05 22:53]
wiki:awksintax [2020/07/17 06:39] (current)
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 +====== The AWK syntax ======
 +The awk syntax is:\\
 +//awk '​[pattern] {action} [pattern]'​ input.txt > output.txt//​\\
 +The awk //line// is always placed between single-quotation (') and not back-quotation (`).\\
 +The awk structure is composed of //​patterns//​ and //​actions.//​\\
 +1. The //​[pattern]//​ (optional feature) can be:
 +  * BEGIN {action} (actions computed before reading the input).
 +  * END  {action} (actions computed at the end of the input).
 +2. The main action ({action}) is computed by reading the input line by line.
 +The actions include commands and operations.\\
 +Therefore the full awk syntax can be represented in this way:\\
 +//awk 'BEGIN {action} {action} END {action}'​ input.txt > output.txt//​\\
 +in practice\\
 +//awk 'BEGIN {action before the input.txt reading } {action during the input.txt reading} END {action after the input.txt reading}'​ input.txt > output.txt//​\\