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shellawkstrip

Awk: Strip all characters except whitelisted ones from a column

   awk 'length($1)==3 && length($2)==3 {print $1, $2 "\t", $5}' file.txt

I am trying to print the column with only one character.

It could be either A or B or C or D , negate every thing else in $5.

$5 in file.txt is 

112C
222F
B212
F2334
C23
A123

I want the output to be

 C

 B

 C
 A
Solution

  • To remove all characters except A, B, C, and D from $5, use gsub(/[^ABCD]/, "", $5)

    Applied to your command:

    awk 'length($1)==3 && length($2)==3 { 
  gsub(/[^ABCD]/, "", $5);
  print $1, $2 "\t" $5
}' file.txt