Surround every line with single quote except empty lines - unix

Question

My goal is to add a single apostrophe to every line in the file and skip empty lines.
file.txt:
Quote1
Quote2
Quote3
So far I have used sed:
sed -e "s/\(.*\)/'\1'/"
Which does the job but creates apostrophes also in empty lines:
'Quote1'
'Quote2'
''
'Quote3'
My goal:
'Quote1'
'Quote2'
'Quote3'
How could I achieve this by using sed, or maybe it should it be awk.

Answer 1

.* means zero or more characters, you want 1 or more characters which in any sed would be ..*:
$ sed "s/..*/'&'/" file
'Quote1'
'Quote2'
'Quote3'
You can also write that regexp as .\+ in GNU sed, .\{1,\} in POSIX seds, and .+ in GNU or OSX/BSD sed when invoked with -E.
The above assumes lines of all blanks should be quoted. If that's wrong then:
$ sed "s/.*[^[:blank:]].*/'&'/" file
'Quote1'
'Quote2'
'Quote3'
In any awk assuming lines of all blanks should be quoted:
$ awk '/./{$0="\047" $0 "\047"}1' file
'Quote1'
'Quote2'
'Quote3'
otherwise:
$ awk 'NF{$0="\047" $0 "\047"}1' file
'Quote1'
'Quote2'
'Quote3'
You can see the difference between the above with this:
$ printf ' \n' | sed "s/..*/'&'/"
' '
$ printf ' \n' | sed "s/.*[^[:blank:]].*/'&'/"
$ printf ' \n' | awk '/./{$0="\047" $0 "\047"}1'
' '
$ printf ' \n' | awk 'NF{$0="\047" $0 "\047"}1'
$

Answer 2

One way:
awk '$1{$0 = q $0 q}1' q="'" file
Add quotes only if 1st column($1) has some value. 1 to print every line.

Answer 3

Assuming you want to add the single quotes to lines that contain nothing but whitespace:
sed -E "/./s/(.*)/'\1'/"

Answer 4

Another sed
sed '/^$/!{s/^/\x27/;s/$/\x27/}' file
The above script says
Look for an empty line - /^$/ - pattern.
For those lines that doesn't follow the above pattern(!), substitute start(^) and end($) with single quotes(\x27).

Answer 5

You can use perl to check for a negative lookbehind, asserting that you won't match an "empty" line:
perl -pe 's/(?<!$)(.*)/"\1"/' file
Another alternative is being more specific in your regex, as #edmorton suggested in his answer.

Answer 6

tried on gnu sed
sed -E "s/\S+/'&'/" file.txt