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in reply to Print only if pattern matches

Your long regex

s/^(.*\|)*.*ABC\.pi=([\d.]+|[\w.]+)*.*ABC\.id=(\d+|[\w.]+).*$/$1$2 +|$3/s;
can be futher reduced to match your required output.
Using the solution provided by kenosis like so:
use strict; use warnings; while (<DATA>) { next unless /^\d+\|(\d+?)\|/ and $1 == 1; if (/(.+?)~.+?=(.+?)~.+=(.+?)$/) { # note here print $1, $2, $3, $/; } else { print "Exception: ", $_, $/; } } __DATA__ 123|1|456464|645646|4546|654~abc~dhghga~ABC.pi=112.33.44.55.66~ABC.id= +789137136770 123|1|456464|645646|4546|654~abc~dhghga~ABC.pi=112.33.44.55.67~ABC.id= +789134713670 123|1|456464|645646|4546|654~abc~dhghga~ABC.pi=112.33.44.55.68~ABC.id= +789137213670 123|1|456464|645646|4546|654~abc~dhghga~ABC.pi=112.33.44.55.69~ABC.id= +78913713670 123|1|456464|645646|4546|654~abc~dhghga~12.33.44.55.70~3713670 123|1|456464|645646|4546|654~abc~dhghga~ABC.pi=112.33.44.55.70~ABC.id= +78913713670 123|1|456464|645646|4546|654~abc~dhghga~ABC.pi=112.33.44.55.70~ABC.id= +78913713670 123|1|456464|645646|4546|654~abc~dhghga~ABC.pi=112.33.44.55.70~ABC.id= +789137135670 123|1|456464|645646|4546|654~abc~dhghga~ABC.pi=112.33.44.55.70~ABC.id= +789137153670 123|1|456464|645646|4546|654~abc~dhghga~12.33.44.55.70~3713670 123|1|456464|645646|4546|654~abc~dhghga~121322~456466874~8796896 123|2|456464|645646|4546|654~abc~dhghga~121322~456466874~6788708 123|2|456464|645646|4546|654~abc~dhghga~121322~456466874~6806
Output:
123|1|456464|645646|4546|654112.33.44.55.66789137136770 123|1|456464|645646|4546|654112.33.44.55.67789134713670 123|1|456464|645646|4546|654112.33.44.55.68789137213670 123|1|456464|645646|4546|654112.33.44.55.6978913713670 Exception: 123|1|456464|645646|4546|654~abc~dhghga~12.33.44.55.70~3713 +670 123|1|456464|645646|4546|654112.33.44.55.7078913713670 123|1|456464|645646|4546|654112.33.44.55.7078913713670 123|1|456464|645646|4546|654112.33.44.55.70789137135670 123|1|456464|645646|4546|654112.33.44.55.70789137153670 Exception: 123|1|456464|645646|4546|654~abc~dhghga~12.33.44.55.70~3713 +670 Exception: 123|1|456464|645646|4546|654~abc~dhghga~121322~456466874~87 +96896

If you tell me, I'll forget.
If you show me, I'll remember.
if you involve me, I'll understand.
--- Author unknown to me