求一个shell脚本删除文本中指定行

Question

我有一个文本文档记录了很多deb软件包的信息，给个例子：
Package: 2vcard
Priority: optional
Section: utils
Installed-Size: 108
Maintainer: Martin Albisetti <[email protected]>
Architecture: all
Version: 0.5-3
Filename: pool/main/2/2vcard/2vcard_0.5-3_all.deb
Size: 14300
MD5sum: d831fd82a8605e9258b2314a7d703abe
SHA1: e903a05f168a825ff84c87326898a182635f8175
SHA256: 2be9a86f0ec99b1299880c6bf0f4da8257c74a61341c14c103b70c9ec04b10ec
Description: perl script to convert an addressbook to VCARD file format
2vcard is a little perl script that you can use to convert the
popular vcard file format. Currently 2vcard can only convert addressbooks
and alias files from the following formats: abook,eudora,juno,ldif,mutt,
mh and pine.
.
The VCARD format is used by gnomecard, for example, which is used by the
balsa email client.
Tag: implemented-in::perl, role::program, use::converting

现在我想保留以“Pre-depends:"或"Depends:"或"Filename:"开头的信息，把其他的都过滤掉。怎么实现？？

Answer 1

grep就ok了，加上-E参数：
示例：
bsstest2:/billing/app/user/xufc/test$grep -E "^Pre-depends:|^Depends:|^Filename:" info.txt
Filename: pool/main/2/2vcard/2vcard_0.5-3_all.deb
你给的文件中只有一个Filename开头的，所以只有一个结果
下面我换个搜索条件，显示可能会更加清晰：
bsstest2:/billing/app/user/xufc/test$grep -E "^Section:|^Version:|^Filename:" info.txt
Section: utils
Version: 0.5-3
Filename: pool/main/2/2vcard/2vcard_0.5-3_all.deb
bsstest2:/billing/app/user/xufc/test$
其中info.txt就是你给的示例文件

Answer 2

cat text |egrep -i "^Depends|^Filename:|^Pre-depends:" >> mynewfile
实例如下：

[lotto@ftptest2 ~]$ cat text
Package: 2vcard
Priority: optional
Section: utils
Installed-Size: 108
Maintainer: Martin Albisetti <[email protected]>
Architecture: all
Version: 0.5-3
Filename: pool/main/2/2vcard/2vcard_0.5-3_all.deb
Size: 14300
MD5sum: d831fd82a8605e9258b2314a7d703abe
SHA1: e903a05f168a825ff84c87326898a182635f8175
SHA256: 2be9a86f0ec99b1299880c6bf0f4da8257c74a61341c14c103b70c9ec04b10ec
Description: perl script to convert an addressbook to VCARD file format
2vcard is a little perl script that you can use to convert the
popular vcard file format. Currently 2vcard can only convert addressbooks
and alias files from the following formats: abook,eudora,juno,ldif,mutt,
mh and pine.
.
The VCARD format is used by gnomecard, for example, which is used by the
balsa email client.
Tag: implemented-in::perl, role::program, use::converting
[lotto@ftptest2 ~]$ cat text |egrep -i "^Depends|^Filename:|^Pre-depends:" >> mynewfile
[lotto@ftptest2 ~]$ cat mynewfile
Filename: pool/main/2/2vcard/2vcard_0.5-3_all.deb