Shell Programming and Scripting

 for ((i=0;i<130;i++)); do echo " $i "|grep -v -e " [0-9] " -e " [0-9][0-9] " -e " 1[0-1][0-9] " -e " 12[0-3] "

 124
 125
 126
 127
 128
 129

$
$
$ cat f18
400.232352,ATK4875739,234,2,33,3  # show, because no. from beginning to 1st comma is decimal and > 123
100.23,XYZ,0                      # don't show, because no. from beginning to 1st comma is decimal but < 123
125,ABC,0                         # don't show, because no. from beginning to 1st comma is not a decimal
12PQR,DEF,0                       # don't show, because chars from beginning to 1st comma do not represent a number
123.000001,ATK4875739,234,2,33,3  # show, because no. from beginning to 1st comma is decimal and > 123
-100.23,MNO,0                     # don't show, because no. from beginning to 1st comma is decimal but < 123
$
$
$ perl -lne '/^(.*?),.*/; print if $1 !~ /[a-zA-Z]/ and int($1) != $1 and $1 > 123' f18
400.232352,ATK4875739,234,2,33,3  # show, because no. from beginning to 1st comma is decimal and > 123
123.000001,ATK4875739,234,2,33,3  # show, because no. from beginning to 1st comma is decimal and > 123
$
$
$

awk -F, '/,/{if($1>123){print}next}{x=$0;gsub(/[^0-9]/,"");if($0+0>123){print x} }' inputFile

$ cat file
rdate NTPserver login 115 /var/log
rdate NTPserver login 123.4 /var/log
rdate NTPserver login 123 /var/log
rdate NTPserver login 124 /var/log
400.232352,ATK4875739,234,2,33,3
110.232352,ATK4875739,234,2,33,3

$ awk -F, '/,/{if($1>123){print}next}{x=$0;gsub(/[^0-9]/,"");if($0+0>123){print x} }' file
rdate NTPserver login 123.4 /var/log
rdate NTPserver login 124 /var/log
400.232352,ATK4875739,234,2,33,3

echo "rdate NTPserver login 140 /var/log
rdate NTPserver login 121 /var/log" | \
   awk '{var=$0; var=gensub(/[^[:digit:]*]/,"","g",var); if ( var > 123 ) { print $0}}'