sed and awk notes

Some useful notes:

Chart of similar operations with sed and awk
--------------------------------------------

string
======

sed "s/from/to/" awk '{sub("from","to"); print}'

sed "s/from/to/g" awk '{gsub("from","to"); print}'

sed "s/from/to/3" awk '{$0=gensub("from","to",3); print}'


regex
=====

sed "s/reg.*$/_&_/" awk '{sub(/reg.*$/, "_&_"); print}'

sed "s/reg[ex]/YY/g" awk '{gsub(/reg[ex]/, "YY"); print}'

sed "s/reg[ex]/ZZ/4" awk '{$0=gensub(/reg[ex]/, "ZZ", 4); print}'


awk variable "var"
==================

sed "s/bang/boom/" awk -v var="bang" '{sub(var,"boom");print}'

sed "s/.*=/equ/5" awk -v var=".*=" '{$0=gensub(var,"equ",5);print}'



DOS variable "XY" with awk variable "z"
=======================================

[DOSPROMPT] C:\path> set xy=bangg*

sed "s/%XY%/boom/" awk -v z="%XY" '{sub(z,"boom"); print}'

sed "s/%XY%/boom/g" awk -v z="%XY" '{gsub(z,"boom"); print}'

sed "s/%XY%/boom/5" awk -v z="%XY" '{$0=gensub(z,"boom",5); print}'


interval expression, \{M,N\}
============================

sed "s/fo\{3,8\}/bar/" awk --re-interval '{sub(/fo{3,8}/, "bar");print}'

sed "s/fo\{3,8\}/bar/g"

awk --re-interval -v a="fo{3,8}" '{gsub(a,"bar");print}'
or
awk --re-interval -v a="fo\{3,8\}" '{gsub(a,"bar");print}'



DOS variable "HI", awk variable "j" with interval expression
============================================================

[DOSPROMPT] C:\path> set hi=Whe\{2,7\}!*

sed "s/%hi%/Zow!/" awk --re-interval -v j="%hi" '{sub(j,"Zow!"); print}'

sed "s/%hi%/Zow!/g" awk --re-interval -v j="%hi" '{gsub(j,"Zow!");print}'

[DOSPROMPT] C:\path> REM ... using a disk file ...
[DOSPROMPT] C:\path> echo {$0=gensub(j,"Zow!",5); print} >myfile.awk

sed "s/%hi%/Zow!/5" awk --re-interval -v j="%hi" -f myfile.awk


--
compiled by Eric Pement
on 03/20/2001 07:11pm

[end-of-file]

Taken from: http://www.student.northpark.edu/pemente/awk/awk_sed.txt