如何添加字符串＆＃34; <fc = ff00>＆＃34;在包含模式[：alpha：]的任何行之前，但不添加两个连续的行？

Question

考虑这个示例文件：

01
00:00:00,000 --> 00:00:00,000
Alphabetic characters.
02
00:00:00,000 --> 00:00:00,000
Alphabetic characters
Alphabetic characters,
03
00:00:00,000 --> 00:00:00,000
Alphabetic characters,

我只想在一行文字中添加字符串。

01
00:00:00,000 --> 00:00:00,000
<fc=ff00 >Alphabetic characters,
02
00:00:00,000 --> 00:00:00,000
<fc=ff00>Alphabetic characters
Alphabetic characters,
03
00:00:00,000 --> 00:00:00,000
<fc=ff00>Alphabetic characters,

使用sed：     sed＆＃39; / [[：alpha：]] / s / ^ //＆＃39;文件＆gt; new_file

我不清楚如何排除第二行。有什么建议吗？

Answer 1

$ awk '!f && /[[:alpha:]]/{print "<fc=ff00>" $0; f=1; next} {print; f=0}' file
01
00:00:00,000 --> 00:00:00,000
<fc=ff00>Alphabetic characters.
02
00:00:00,000 --> 00:00:00,000
<fc=ff00>Alphabetic characters
Alphabetic characters,
03
00:00:00,000 --> 00:00:00,000
<fc=ff00>Alphabetic characters,