Update column in File

Shell Programming and Scripting
1

I Have a file a.txt in the below format

1 23 50
1 25 6666666666666
1 23 34

If the third column value is greater than two digit then make it 0

New Data File
---------------
a.txt
1 23 50
1 25 0
1 23 34

Need your help regarding this

2 
awk '$3 > 99 {$3=0}'1 file
3

Using some posixsh (ksh, bash, dash ...)

while read a1 a2 a3 x
do
        ((a3<100)) && echo "$a1 $a2 $a3" && continue
        echo "$a1 $a2 0"
done < a.txt

Or if file is big, then awk is better - faster.

awk '
{       if ($3>99) $3=0
        print
}' a.txt
# or
awk '
$3 > 99 { $3=0  }
        { print }
' a.txt
4

:b:

awk '$3 > 99 {$3=0}'1 file

This Works fine .Can you please explain what is this 1

5

1 => Print line being read

6 
awk '(length($3)>2){$3=0}'1 filename