Match digits in [g]awk

问题

I'm stumped! Trying to write an awk regex to match a string against 11 digits.

I've tried:

if (var ~ /^[0-9]{11}$/ )
if (var ~ /^([0-9]){11}$/ )
if (var ~ /^([0-9]{11})$/ )
if (var ~ /^[0-9]{11}/ ) # altho I really do need to check the whole str
if (var ~ /[0-9]{11}/ )

If I use this....

if (var ~ /^[0-9]+/ ) 

Then I get a match - but I need to check for exactly 11 digits.

回答1:

You described your problem, but didn't tell us your awk version. It is an important information.

but this may work for your case:

if (var ~ /^[0-9]+$/ && length(var)==11)

If we know the version, there could be simpler solution.

回答2:

If you are trying to match exactly 11 consecutive digits someplace in the string:

Using the test file:

hi12345678910
hi1234

The windows version of awk command line:

awk --posix "{ if ($1 ~ /[0-9]{11}/) print}" testfile.txt

It printed:

hi12345678910

回答3:

Doh - forgot to RTM:

              Interval expressions are only available if either --posix or
              --re-interval is specified on the command line.

来源：https://stackoverflow.com/questions/16088141/match-digits-in-gawk