UNIX for Dummies Questions & Answers

Code:

awk 'BEGIN { RS=">"; FS="\n"; ORS="" } !/[-*]/&&c++ { print ">" $0; }'

c will be incremented After the comparison so at first comparison, c is null so the heading ">" will be skipped

Or as follow ... so if there are some lines before the first ">", then won't be missed (depending on the expected output):

Code:

awk 'BEGIN { RS=">"; FS="\n"; ORS="" } !/[-*]/{ print ((c++)?">":z) $0; }'

Would you mind explaining the last part of your code to me?

Code:

((c++)?">":z)

It's an obscure syntax for choosing between two values depending on what the value of x is. You also find it in the C language, which awk borrows much of its syntax from.

Code:

(SOMETHING ? truevalue : falsevalue)

So when SOMETHING evaluates true, the expression becomes truevalue, and when SOMETHING evaluates false, the expression becomes falsevalue. So you get the variable 'z' on the first loop, and ">" every loop thereafter.

Why z? One less key than "", I guess.

Corona,
Thank you very much!
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