Macos – does grep regex work differently on mac

Try --host=127.0.0.1 because the mysql client is trying to connect using the standard mysql socket (/tmp/mysql.sock). Specifying an IP address won't use this socket connection. I had to change this in every program to be able to connect to the MAMP database, including Sequel Pro.

Well, here's a wikipedia page for matching or replacing with Perl one liners. I did this in Cygwin:

Perl can behave like grep or like sed.

The /s makes dot match new line.

The -0777 makes it apply the regular expression to the whole thing instead of line by line.

\n can match new line as well.

$ echo -e 'a\nb\nc\nd' | perl -0777 -pe 's/.*c//s'

d

user@comp ~
$ echo -e 'a\nb\nc\nd' | perl -pe 's/.*c//s'
a
b

d

Here is the other form, -ne with print $1:

user@comp ~
$ echo -e 'a\nb\nc\nd' | perl -ne 'print $1 if /(.*c)/s'
c
user@comp ~
$ echo -e 'a\nb\nc\nd' | perl -0777 -ne 'print $1 if /(.*c)/s'
a
b
c
user@comp ~
$

Also

$ echo xxx|perl -lne 'print ""'

Perl's equivalent of \0 or &, i.e. the whole match is $_ or to be able to put text before and after without a space, ${_}

$ echo xxx|perl -lne 'print "a${_}${_}a"'
axxxxxxa

and

$  echo xxx|perl -lpe 's/.*/a${_}${_}a"/'
axxxxxxa"

###Some further examples

$ cat t.t
<ul>
 <li>item 1</li>
 <li>item 2</li>
</ul>

$ perl -0777 -ne 'print $1 if /\<ul\>(.*?)\<\/ul>/s' t.t

 <li>item 1</li>
 <li>item 2</li>

user@comp ~
$ perl -0777 -ne 'print $1 if /(.*)/s' t.t
<ul>
 <li>item 1</li>
 <li>item 2</li>
</ul>

user@comp ~
$

An example of Global for the -ne one (change "if" to "while"):

$ echo -e 'bbb' | perl -0777 -ne 'print $1 while /(b)/sg'
bbb

For the -pe one, just add the g at the end (/sg or /gs, same thing):

$  echo -e 'aaa' | perl -0777 -pe 's/a/z/s'
zaa

user@comp ~
$  echo -e 'aaa' | perl -0777 -pe 's/a/z/sg'
zzz

Note- This question contrasts /s and -0777

Those print $1 examples don't show the whole line. this link https://dzone.com/articles/perl-as-a-better-grep has this example that does perl -wln -e "/RE/ and print;" foo.txt