Regular expression in AWK


 
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# 1  
Old 05-07-2009
Regular expression in AWK

Hello world,

I was wondering if there is a nicer way to write the following code (in AWK):

Code:
 
awk '
FNR==NR&&$1~/^m[24689]$/{tok1=1}
FNR==NR&&$1~/^m10$/{tok1=1}
' my_file

In fact, it looks for m2, m4, m6, m8 and m10 and then return a positive flag. The problem is how to define 10 thanks to regular expresions?
Is there a way do a list of possible values, like "{2,4,6,8,10}"?

Let me know,

Thanks
# 2  
Old 05-07-2009
how 'bout;
Code:
awk '
FNR==NR { tok1=($1 ~ "^m([24689]|10)$" ? 1 : 0}
' my_file

# 3  
Old 05-07-2009
Thanks, that is what I was looking for!


Quote:
Originally Posted by vgersh99
how 'bout;
Code:
awk '
FNR==NR { tok1=($1 ~ "^m([24689]|10)$" ? 1 : 0}
' my_file

# 4  
Old 05-08-2009
Quote:
Originally Posted by vgersh99
how 'bout;
Code:
awk '
FNR==NR { tok1=($1 ~ "^m([24689]|10)$" ? 1 : 0}
' my_file

There's a missing close parenthesis after the last zero and NR==FNR is unnecessary if you have 1 input file, this should be sufficient:

Code:
awk '{tok1=/^m([24689]|10)$/?1:0}' file

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