Shell Programming and Scripting

Dear all,

I have a file which have let us say records from A-Z.

Now I want to remove multiple letter from this file using single command.. let us say I want to remove A,F,K,Y,U,P,B,S,D.

I can use grep -v command but for this case i need to rerun the file several time i wana avoid using multiple command and wants the result from single command also output file should also be in a single file.

Can anyone advice.

To remove A and F you can do something like:

Code:

awk '
!/A/ &&
!/F/ &&
' file > newfile

awk is usually far more elegant for this sort of thing but I think you answered your own question, you can of course use multiple "grep -v" in one go, e.g.:

Code:

$ grep -v A inputfile | grep -v F | grep -v K | grep -v Y | grep -v U | grep -v P | \
  grep -v B | grep -v S | grep -v D > outputfile

If each record starts with the letter concerned then using:

Code:

grep -v "^A"

for each "grep -v" would be better, i.e. remove all lines that start with a capital A.

How about:

Code:

egrep -v "^(A|F|K|Y|U|P|B|S|D)" infile

Code:

sed "/^\(A\|F\|K\|Y\|U\|P\|B\|S\|D\)/d" infile

Code:

sed -r "/^(A|F|K|Y|U|P|B|S|D)/d" infile

or in this case:

Code:

sed '/^[AFKYUPBSD]/d' infile

You can leave the caret (^) out if do not only want to delete records that start with a letter but any record that contains a lettter.