CODEWITHSUNDEEP
awksed
calabash
calabash

Reputation: 115

Delete "0" or "1" from the end of each line, except the first line

the input file looks like

Kick-off team   68  0
Ball safe       69  1
Attack          77  8
Attack          81  4
Throw-in        83  0
Ball possession 86  3
Goal kick       100 10
Ball possession 101 1
Ball safe       114 13
Throw-in        123 9
Ball safe       134 11
Ball safe       135 1
Ball safe       137 2

and at the end it should look like this:

Kick-off team   68  0
Attack          77  8
Attack          81  4
Ball possession 86  3
Goal kick       100 10
Ball safe       114 13
Throw-in        123 9
Ball safe       134 11
Ball safe       137 2

my solution is

awk '{print $NF}' test.txt | sed -re '2,${/(^0$|^1$)/d}'

how can i directly change the file, e.g. sed -i?

Upvotes: 0

Views: 67

Answers (4)

karakfa
karakfa

Reputation: 67467

awk to the rescue!

$ awk 'NR==1 || $NF && $NF!=1' file

or more cryptic

$ awk 'NR==1 || $NF*($NF-1)' file

Upvotes: 1

potong
potong

Reputation: 58371

This might work for you (GNU sed):

sed -i '1b;/\s[01]$/d' file

Other than the first line, delete any line ending in 0 or 1.

Upvotes: 0

ghoti
ghoti

Reputation: 46826

Here's my take on this.

sed -i.bak -e '1p;/[^0-9][01]$/d' file.txt

The sed script prints the first line, then deletes all subsequent lines that match the pattern you described. This assumes that your first line would be a candidate for deletion; if it contains something other than 0 or 1 in the last field, this script will print it twice. And the -i option is what tells sed to edit in-place (with a backup file).

Awk doesn't have an equivalent option for editing files in-place -- if you want that kind of functionality, you need to implement it in a shell wrapper around your awk script, as @sundeep suggested.

Note that I'm not using GNU sed, but this command should work equally well with it.

Upvotes: 1

Sundeep
Sundeep

Reputation: 23667

sed -i '2,$ {/[^0-9][01]$/d}' test.txt
  • 2,$ lines to act upon, this one says 2nd line to end of file
  • {/[^0-9][01]$/d} from filtered lines, delete those ending with 0 or 1
    • '2,$ {/ [01]$/d}' can be also used if character before last column is always a space


With awk which is better suited for column manipulations:

awk 'NR==1 || ($NF!=1 && $NF!=0)' test.txt > tmp && mv tmp test.txt
  • NR==1 first line
  • ($NF!=1 && $NF!=0) last column shouldn't be 0 or 1
    • can also use $NF>1 if last column only have non-negative numbers
  • > tmp && mv tmp test.txt save output to temporary file and then move it back as original file
  • With GNU awk, there is inplace option awk -i inplace 'NR==1 || ($NF!=1 && $NF!=0)' test.txt

Upvotes: 2

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