CODEWITHSUNDEEP
awk
John Cesar
John Cesar

Reputation: 3

How can I remove lines from a file with more than a certain number of entries

I've looked at the similar question about removing lines with more than a certain number of characters and my problem is similar but a bit trickier. I have a file that is generated after analyzing some data and each line is supposed to contain 29 numbers. For example:

53.0399 0.203827 7.28285 0.0139936 129.537 0.313907 11.3814 0.0137903 355.008 \
0.160464 12.2717 0.120802 55.7404 0.0875189 11.3311 0.0841887 536.66 0.256761 \
19.4495 0.197625 46.4401 2.38957 15.8914 17.1149 240.192 0.270649 19.348 0.230\
402 23001028 23800855
53.4843 0.198886 7.31329 0.0135975 129.215 0.335697 11.3673 0.014766 355.091 0\
.155786 11.9938 0.118147 55.567 0.368255 11.449 0.0842612 536.91 0.251735 18.9\
639 0.184361 47.2451 0.119655 18.6589 0.592563 240.477 0.298805 20.7409 0.2548\
56 23001585
50.7302 0.226066 7.12251 0.0158698 237.335 1.83226 15.4057 0.059467 -164.075 5\
.14639 146.619 1.37761 55.6474 0.289037 11.4864 0.0857042 536.34 0.252356 19.3\
91 0.198221 46.7011 0.139855 20.1464 0.668163 240.664 0.284125 20.3799 0.24696\
23002153

But every once in a while, a line like the first one appears that has an extra 8 digit number at the end from analyzing an empty file (so it just returns the file ID number but not on a new line like it should). So I just want to find lines that have this extra 30th number and remove just that 30th entry. I figure I could do this with awk but since I have little experience with it I'm not sure how. So if anyone can help I'd appreciate it.

Thanks

Summary: Want to find lines in a text file with an extra entry in a row and remove the last extra entry so all rows have same number of entries.

Upvotes: 0

Views: 83

Answers (1)

glenn jackman
glenn jackman

Reputation: 247012

With awk, you tell it how many fields there are per record. The extras are ignored

awk '{NF = 29; print}' filename

If you want to save that back to the file, you have to do a little extra work

awk '{NF = 29; print}' filename > filename.new && mv filename.new filename

Upvotes: 3

Related Questions