文本处理 - 如何截取指定行中间的行？

bikkuri

大家好！
我有一个问题向大家请教。
有以下一个邮件，我想从中取出第一个用base64编码的（黄色）部分，请问应该怎么做呢？

X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR07MB5933

--_004_VI1PR07MB393544AF82248044C36563D39D470VI1PR07MB3935eurp_
Content-Type: multipart/alternative;
        boundary="_000_VI1PR07MB393544AF82248044C36563D39D470VI1PR07MB3935eurp_"

--_000_VI1PR07MB393544AF82248044C36563D39D470VI1PR07MB3935eurp_
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: base64

DQoNCkZyb206IG5tcy1qaXJhQGxpc3Qubm9raWEuY29tIFttYWlsdG86bm1zLWppcmFAbGlzdC5u
b2tpYS5jb21dDQpTZW50OiAyMDE55bm0M+aciDE45pelIDE5OjE2DQpUbzogWmh1LCBKb2huIChO
aWFuIEpJUkEgKHY3LjEuMiM3MTAwNi1zaGExOjhlN2UzMDkpDQoNCltBdGxhc3NpYW4gbG9nb10N
Cg0KDQoNCg0K

--_000_VI1PR07MB393544AF82248044C36563D39D470VI1PR07MB3935eurp_
Content-Type: text/html; charset="utf-8"
Content-Transfer-Encoding: base64

PGh0bWwgeG1sbnM6dj0idXJuOnNjaGVtYXMtbWljcm9zb2Z0LWNvbTp2bWwiIHhtbG5zOm89InVy
bjpzY2hlbWFzLW1pY3Jvc29mdC1jb206b2ZmaWNlOm9mZmljZSIgeG1sbnM6dz0idXJuOnNjaGVt
ZHk+DQo8L3RhYmxlPg0KPHAgY2xhc3M9Ik1zb05vcm1hbCI+PHNwYW4gbGFuZz0iRU4tVVMiPjxv
OnA+Jm5ic3A7PC9vOnA+PC9zcGFuPjwvcD4NCjwvZGl2Pg0KPC9ib2R5Pg0KPC9odG1sPg0K

--_000_VI1PR07MB393544AF82248044C36563D39D470VI1PR07MB3935eurp_--

--_004_VI1PR07MB393544AF82248044C36563D39D470VI1PR07MB3935eurp_
Content-Type: image/png; name="ATT00001.png"
Content-Description: ATT00001.png
Content-Disposition: inline; filename="ATT00001.png"; size=2983;
        creation-date="Mon, 18 Mar 2019 11:16:15 GMT";
        modification-date="Mon, 18 Mar 2019 11:16:15 GMT"
Content-ID:
<jira-generated-image-static-footer-desktop-logo-28db4a1e-0ed6-4b53-8623-df68548fdc63>
Content-Transfer-Encoding: base64

iVBORw0KGgoAAAANSUhEUgAAAKkAAAAkCAYAAADy+xopAAAAG3RFWHRqaXJhLXN5c3RlbS1pbWFn
ZS10eXBlAGxvZ287MIqNAAAFV0lEQVR42u2cLbPrIBCGq1A4VFQUqg4VhUKh4qKizt89+U3ntjNk
Fgn+3VryGnm6ib4uHh/DiMm9gYF5cUEVSp06nW+Vfsr7P2pICseXwfgnBpei1Oix8sBY9a8AAwDk
nvfbckn7YgAAAABJRU5ErkJggg==

--_004_VI1PR07MB393544AF82248044C36563D39D470VI1PR07MB3935eurp_--

谢谢大家的帮助！

cfwyy

1. awk '/base64/{getline;while(getline && $0 !~/^$/){print $0};while(getline){}}' mail.txt
   

复制代码

bikkuri

回复 2# cfwyy

非常感谢您的帮助！