Shell Programming and Scripting

I am testing few existing scripts in our environment as we have migrating from redhat linux 4 to 5 & above.

I am stuck up with one of the script where the search condition is

Code:

/[^[:blank:]]+[[:blank:]]+([[:digit:]\.]+[[:blank:]]+){7,}/ 

the script works fine when i remove {7,} in the search condition if i add this it does not show any results.

Can some one let me know what does this search condition does and what does the {7,} implies the output before and after seems to be the same and i am assuming that 7 is the number of columns in the passwd file.

You can test in this way

Code:

cp /etc/passwd  /tmp/passwd 
  replace the columns with blanks  :/^v/:/ /g  in the /tm/passwd file  

awk 'BEGIN {FS=":"} $1 ~ /[^[:blank:]]+[[:blank:]]+([[:digit:]\.]+[[:blank:]]+){7,}/   /tmp/passwd

Please let me know if someone knows how the search condition works

Moderator's Comments:

How to use code tags

GNU awk does have a quirk in that it does not understand the repetition operator by default.
Try awk --posix

Code:

$ echo hello | gawk '/l{2}/'
$ echo hello | gawk --posix '/l{2}/'
hello