awk for removing spaces

Shell Programming and Scripting
1

HI,

I have a file with lot of blank lines, how can I remove those using awk??

Thanks,
Shruthi

2

hey you can use

awk '/./' infile for removing blank lines
3

can you please explain me how this command works...I mean I don't have any '.' in my file to search for ??

4

awk '!/^$/ {print $0}' test.txt

5

In this context the '.' is not a literal dot/period, but a regex special character/metacharacter that matches (almost) any single character ( reference: Regex Tutorial - The Dot Matches (Almost) Any Character )

So, here it matches all lines that contain any character (ie: that aren't blank). Note if lines contain spaces these are counted as characters so will still be printed, eg:

$ printf 'line1\n \nline3\nline4 with spaces\n\nline6\n'|awk '/./'
line1

line3
line4 with spaces
line6

(line 2 consists of a space, so is still printed. line 5 is a blank line, so it is omitted)