sed替换的问题

zbhdpx

在鸟哥私房菜中有以下示例:
[root@www ~]# nl /etc/passwd | sed '2a drink tea'
1 root:0:0:root:/root:/bin/bash
2 bin:1:1:bin:/bin:/sbin/nologin
drink tea
3 daemon:2:2:daemon:/sbin:/sbin/nologin

在第二行后插入 drink tea
我在freebsd 6.2下怎么试都不行，提示如下:
%nl /etc/passwd | sed '2a drink tea'
sed: 1: "2a drink tea": command a expects \ followed by text

这个是什么问题,怎样写才是正确的？

另外把命令写到文件里执行没问题
%cat change.sed
#!/usr/bin/sed -f
2 a\
drink tea

./change.sed /etc/passwd 这样是正常的.

L_kernel

正规的模式应该是a后面加一个\的。

可能还是gnu的改进的sed

zbhdpx

以下在csh下边试
%nl /etc/passwd | sed '2a\ drink tea'
sed: 1: "2a\ drink tea": extra characters after \ at the end of a command

我加了也是这样，刚又试了一下，可能我用的是csh,


在sh下

# nl /etc/passwd | sed '2a\ drink tea'
sed: 1: "2a\ drink tea": extra characters after \ at the end of a command

# cat test.txt |sed '2c\
> AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
> '

HORSEFEATHERS SOFTWARE PRODUCT BULLETIN
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
  of Horsefeathers  software products  --  Horsefeathers  Business
  BASIC, BASIC  Librarian,  and LIDO.  These software products can
  fill  your    requirements    for    powerful,    sophisticated,
  general-purpose business  software providing you with a base for
  software customization or development.


这样是正常的，

L_kernel

以下在csh下边试
%nl /etc/passwd | sed '2a\ drink tea'
sed: 1: "2a\ drink tea": extra characters af ...
zbhdpx 发表于 2010-12-28 10:08

    bash和bourne shell都不行。同样是在bsd 8.1当中。
nl /etc/passwd | sed '2a\ drink tea'

zbhdpx

%cat test.txt
The honeysuckle band played all night long for only $90.
Too bad the disco floor fell through at 23:10.
The local nurse Miss P.Neave was in attendance.

%cat test.txt | sed '2a\ \回车
? AAAAAAAAAAAAAAAAAAAA \回车
? '回车
The honeysuckle band played all night long for only $90.
Too bad the disco floor fell through at 23:10.
AAAAAAAAAAAAAAAAAAAA
The local nurse Miss P.Neave was in attendance.

在csh下，上边的操作是可行的，但是插入内容不多于一行