How can I add characters at the beginning and end of every non-empty line in Perl?

I would like to use this:

perl -pi -e 's/^(.*)$/\"$1\",/g' /path/to/your/file

for adding " at beginning of line and ", at end of each line in text file. The problem is that some lines are just empty lines and I don't want these to be altered. Any ideas how to modify above code or maybe do it completely differently?

Others have already answered the regex syntax issue, let's look at that style.

s/^(.*)$/\"$1\",/g

This regex suffers from "leaning toothpick syndrome" where /// makes your brain bleed.

s{^ (.+) $}{ "$1", }x;

Use of balanced delimiters, the /x modifier to space things out and elimination of unnecessary backwhacks makes the regex far easier to read. Also the /g is unnecessary as this regex is only ever going to match once per line.

perl -pi -e 's/^(.+)$/\"$1\",/g' /your/file

.* matches 0 or more characters; .+ matches 1 or more.

You may also want to replace the .+ with .*\S.* to ensure that only lines containing a non-whitespace character are quoted.

change .* to .+

In other words lines must contain at 1 or more characters. .* represents zero or more characters.

You should be able to just replace the * (0 or more) with a + (1 or more), like so:

perl -pi -e 's/^(.+)$/\"$1\",/g' /path/to/your/file

all you are doing is adding something to the front and back of the line, so there is no need for regex. Just print them out. Regex for such a task is expensive if your file is big.

gawk

$ awk 'NF{print "\042" $0 "\042,"}' file

or Perl

$ perl -ne 'chomp;print "\042$_\042,\n" if ($_ ne "") ' file

sed -r 's/(.+)/"\1"/' /path/to/your/file