Replace comma with newline in sed on MacOS?

Question

I have a file of id\'s that are comma separated. I\'m trying to replace the commas with a new line. I\'ve tried:

sed \'s/,/\\n/g\' file

b

Answer 1

Just to clearify: man-page of sed on OSX (10.8; Darwin Kernel Version 12.4.0) says:

[...]

Sed Regular Expressions

 The regular expressions used in sed, by default, are basic regular expressions (BREs, see re_format(7) for more information), but extended
 (modern) regular expressions can be used instead if the -E flag is given.  In addition, sed has the following two additions to regular
 expressions:

 1.   In a context address, any character other than a backslash (``\'') or newline character may be used to delimit the regular expression.
      Also, putting a backslash character before the delimiting character causes the character to be treated literally.  For example, in the
      context address \xabc\xdefx, the RE delimiter is an ``x'' and the second ``x'' stands for itself, so that the regular expression is
      ``abcxdef''.

 2.   The escape sequence \n matches a newline character embedded in the pattern space.  You cannot, however, use a literal newline charac-
      ter in an address or in the substitute command.

[...]

so I guess one have to use tr - as mentioned above - or the nifty

sed "s/,/^M
/g"

note: you have to type <ctrl>-v,<return> to get '^M' in vi editor