Regular Expression repeat pattern

Shell Programming and Scripting
1

Hi,

I'm struggling with very very simple task but dont know where I'm going wrong.
Have the following file numbers.txt

1
12
123
1234
12345
123456
1234567
12345678
123456789
1234567890
9876543210
987654321
98765432
9876543
987654
98765
9876
987
98
9

Tried the following commands with single quote and double quote to print with min and max limits.

grep     "[0-9]\{3,6\}" numb
grep -e  "[0-9]\{3,6\}" numb

egrep    "[0-9]\{3,6\}" numb
egrep -e "[0-9]\{3,6\}" numb

egrep    "[0-9]{3,6}"   numb
grep     "[0-9]{3,6}"   numb

Only grep "[0-9]\{3,6\}" numb is working but max limit is ignored.

I'm using SunOS Ksh.

2

Try this:

$ cat nums
1
12
123
1234
12345
123456
1234567
12345678
123456789
1234567890
9876543210
987654321
98765432
9876543
987654
98765
9876
987
98
9
$ grep -e  "^[0-9]\{3,6\}$" nums
123
1234
12345
123456
987654
98765
9876
987
$