显然\r是钥匙!

$ sed 's/, /\r/g' file3.txt > file4.txt

转换:

ABFS, AIRM, AMED, BOSC, CALI, ECPG, FRGI, GERN, GTIV, HSON, IQNT, JRCC, LTRE,
MACK, MIDD, NKTR, NPSP, PME, PTIX, REFR, RSOL, UBNT, UPI, YONG, ZEUS

:

ABFS
AIRM
AMED
BOSC
CALI
ECPG
FRGI
GERN
GTIV
HSON
IQNT
JRCC
LTRE
MACK
MIDD
NKTR
NPSP
PME
PTIX
REFR
RSOL
UBNT
UPI
YONG
ZEUS

如果sed的使用倾向于完全使用替换表达式(就像我的一样)，您也可以使用perl -pe来代替

$ echo 'foo,bar,baz' | perl -pe 's/,/,\n/g'
foo,
bar,
baz

只是为了澄清:OSX上sed的手册页(10.8;达尔文内核版本12.4.0)说:

[…]

Sed正则表达式

 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.

[…]

所以我想一个人必须使用tr -如上所述-或者nitty

sed "s/,/^M
/g"

注意:你必须输入<ctrl>-v，<return>才能在vi编辑器中得到'^M'

这适用于MacOS Mountain Lion (10.8)， Solaris 10 (SunOS 5.10)和RHE Linux (Red Hat Enterprise Linux Server release 5.3, Tikanga)……

$ sed 's/{pattern}/\^J/g' foo.txt > foo2.txt

．.． 这里的^J是通过ctrl+v+ J完成的。注意^J前面的\。

另外，我知道RHEL的sed是GNU的，MacOS的sed是基于FreeBSD的，虽然我不确定Solaris的sed，但我相信这对任何sed都适用。YMMV tho”……

为了使它完整，也可以这样做:

echo "a,b" | sed "s/,/\\$(echo -e '\n\r')/"

虽然我写这篇文章晚了，只是更新我的发现。这个答案只适用于Mac OS X。

$ sed 's/new/
> /g' m1.json > m2.json
sed: 1: "s/new/
/g": unescaped newline inside substitute pattern

在上面的命令中，我尝试用Shift+Enter添加新行，但没有工作。所以这一次我尝试了“转义”的“未转义换行”，因为错误告诉。

$ sed 's/new/\
> /g' m1.json > m2.json 

成功了!(适用于Mac OS X 10.9.3)