title: How to break a single line into rows where .txt acts as delimiter
body: <p>I'm looking to split the following file into rows based on the .txt extension, which acts as a column identifier.</p>
  
  <p>I would like to use bash/awk to do this. Can I get some assistance around how I may achieve this?</p>
  
  <p>ORIGINAL FILE</p>
  
  <pre><code>   5001-A.txt:Sun Jun 23 07:37:21.687 UTC 5001-A.txt: Active Packages: 8 5001-A.txt: ncs5k-xr-6.5.3 version=6.5.3 [Boot image] 5001-A.txt: ncs5k-mpls-3.1.0.0-r653 5001-A.txt: ncs5k-isis-2.1.0.0-r653 5001-A.txt: ncs5k-mpls-te-rsvp-1.0.0.0-r653 5001-A.txt: ncs5k-ospf-2.0.0.0-r653 5001-A.txt: ncs5k-mcast-2.1.0.0-r653 5001-A.txt: ncs5k-mgbl-3.0.0.0-r653 5001-A.txt: ncs5k-k9sec-3.1.0.0-r653 5001-B.txt:Sun Jun 23 07:36:17.743 UTC 5001-B.txt: Active Packages: 8 5001-B.txt: ncs5k-xr-6.5.3 version=6.5.3 [Boot image] 5001-B.txt: ncs5k-mpls-3.1.0.0-r653 5001-B.txt: ncs5k-isis-2.1.0.0-r653 5001-B.txt: ncs5k-mpls-te-rsvp-1.0.0.0-r653 5001-B.txt: ncs5k-ospf-2.0.0.0-r653 5001-B.txt: ncs5k-mcast-2.1.0.0-r653 5001-B.txt: ncs5k-mgbl-3.0.0.0-r653 5001-B.txt: ncs5k-k9sec-3.1.0.0-r653 540-A.txt:Sun Jun 23 07:29:10.954 UTC 540-A.txt: Active Packages: 10 540-A.txt: ncs540-xr-6.3.2 version=6.3.2 [Boot image] 540-A.txt: ncs540-mpls-1.0.0.0-r632 540-A.txt: ncs540-isis-1.0.0.0-r632 540-A.txt: ncs540-mcast-1.0.0.0-r632 540-A.txt: ncs540-mgbl-1.0.0.0-r632 540-A.txt: ncs540-ospf-1.0.0.0-r632 540-A.txt: ncs540-mpls-te-rsvp-1.0.0.0-r632 540-A.txt: ncs540-li-1.0.0.0-r632 540-A.txt: ncs540-eigrp-1.0.0.0-r632 540-A.txt: ncs540-k9sec-1.0.0.0-r632 5501-A.txt:Sun Jun 23 07:39:57.757 UTC 5501-A.txt: Active Packages: 7 5501-A.txt: ncs5500-xr-6.5.3 version=6.5.3 [Boot image] 5501-A.txt: ncs5500-mpls-2.1.0.0-r653 5501-A.txt: ncs5500-k9sec-3.1.0.0-r653 5501-A.txt: ncs5500-mgbl-3.0.0.0-r653 5501-A.txt: ncs5500-isis-2.1.0.0-r653 5501-A.txt: ncs5500-mpls-te-rsvp-3.1.0.0-r653 5501-A.txt: ncs5500-ospf-2.0.0.0-r653 5502-A.txt:Sun Jun 23 07:45:41.923 UTC 5502-A.txt: Active Packages: 9 5502-A.txt: ncs5500-xr-6.3.2 version=6.3.2 [Boot image] 5502-A.txt: ncs5500-mcast-2.1.0.0-r632 5502-A.txt: ncs5500-mpls-2.1.0.0-r632 5502-A.txt: ncs5500-mgbl-4.0.0.0-r632 5502-A.txt: ncs5500-mpls-te-rsvp-2.2.0.0-r632 5502-A.txt: ncs5500-ospf-2.0.0.0-r632 5502-A.txt: ncs5500-isis-1.3.0.0-r632 5502-A.txt: ncs5500-li-1.0.0.0-r632 5502-A.txt: ncs5500-k9sec-4.1.0.0-r632 55A1-A.txt:Sun Jun 23 07:42:04.974 UTC 55A1-A.txt: Active Packages: 7 55A1-A.txt: ncs5500-xr-6.5.3 version=6.5.3 [Boot image] 55A1-A.txt: ncs5500-mpls-2.1.0.0-r653 55A1-A.txt: ncs5500-k9sec-3.1.0.0-r653 55A1-A.txt: ncs5500-mgbl-3.0.0.0-r653 55A1-A.txt: ncs5500-mcast-2.1.0.0-r653 55A1-A.txt: ncs5500-isis-2.1.0.0-r653 55A1-A.txt: ncs5500-ospf-2.0.0.0-r653 9010-A.txt:Sun Jun 23 17:47:19.268 AEST 9010-A.txt:Default Profile: 9010-A.txt: SDRs: 9010-A.txt: Owner 9010-A.txt: Active Packages: 9010-A.txt: disk0:asr9k-services-infra-6.5.3 9010-A.txt: disk0:asr9k-services-px-6.5.3 9010-A.txt: disk0:asr9k-mpls-px-6.5.3 9010-A.txt: disk0:asr9k-mini-px-6.5.3 9010-A.txt: disk0:asr9k-optic-px-6.5.3 9010-A.txt: disk0:asr9k-li-px-6.5.3 9010-A.txt: disk0:asr9k-doc-px-6.5.3 9010-A.txt: disk0:asr9k-video-px-6.5.3 9010-A.txt: disk0:asr9k-bng-px-6.5.3 9010-A.txt: disk0:asr9k-mgbl-px-6.5.3 9010-A.txt: disk0:asr9k-mcast-px-6.5.3 9010-A.txt: disk0:asr9k-9000v-nV-px-6.5.3 9010-A.txt: disk0:asr9k-fpd-px-6.5.3 9010-A.txt: disk0:asr9k-k9sec-px-6.5.3 9010-B.txt:Sun Jun 23 17:47:23.925 AEST 9010-B.txt:Default Profile: 9010-B.txt: SDRs: 9010-B.txt: Owner 9010-B.txt: Active Packages: 9010-B.txt: disk0:asr9k-mini-px-6.6.2 9010-B.txt: disk0:asr9k-services-infra-6.6.2 9010-B.txt: disk0:asr9k-9000v-nV-px-6.6.2 9010-B.txt: disk0:asr9k-bng-px-6.6.2 9010-B.txt: disk0:asr9k-doc-px-6.6.2 9010-B.txt: disk0:asr9k-fpd-px-6.6.2 9010-B.txt: disk0:asr9k-k9sec-px-6.6.2 9010-B.txt: disk0:asr9k-li-px-6.6.2 9010-B.txt: disk0:asr9k-mcast-px-6.6.2 9010-B.txt: disk0:asr9k-mgbl-px-6.6.2 9010-B.txt: disk0:asr9k-mpls-px-6.6.2 9010-B.txt: disk0:asr9k-optic-px-6.6.2 9010-B.txt: disk0:asr9k-services-px-6.6.2 9010-B.txt: disk0:asr9k-video-px-6.6.2 9904-A.txt:Sun Jun 23 17:46:57.761 AEST 9904-A.txt:Default Profile: 9904-A.txt: SDRs: 9904-A.txt: Owner 9904-A.txt: Active Packages: 9904-A.txt: disk0:asr9k-mini-px-6.6.2 9904-A.txt: disk0:asr9k-services-infra-6.6.2 9904-A.txt: disk0:asr9k-9000v-nV-px-6.6.2 9904-A.txt: disk0:asr9k-bng-px-6.6.2
  </code></pre>
  
  <p>DESIRED OUTPUT</p>
  
  <pre><code>$ cat testfile.txt
  5001-A.txt:Sun Jun 23 07:37:21.687 UTC
  5001-A.txt: Active Packages: 8 
  5001-A.txt: ncs5k-xr-6.5.3 version=6.5.3 [Boot image] 
  5001-A.txt: ncs5k-mpls-3.1.0.0-r653 
  5001-A.txt: ncs5k-isis-2.1.0.0-r653 
  5001-A.txt: ncs5k-mpls-te-rsvp-1.0.0.0-r653 
  5001-A.txt: ncs5k-ospf-2.0.0.0-r653 
  5001-A.txt: ncs5k-mcast-2.1.0.0-r653 
  540-A.txt: Active Packages: 10 
  540-A.txt: ncs540-xr-6.3.2 version=6.3.2 [Boot image] 
  540-A.txt: ncs540-mpls-1.0.0.0-r632 
  540-A.txt: ncs540-isis-1.0.0.0-r632 
  9010-A.txt: disk0:asr9k-9000v-nV-px-6.5.3
  9010-A.txt: disk0:asr9k-fpd-px-6.5.3
  </code></pre>
  
  <p>etc.</p>
  
  <p>Thanks.</p>
  
  <hr>
  
  <p>@Cyrus, the highlighted line is not rendered correctly. It happens when we move between different .txt names.</p>
  
  <pre><code>5001-B.txt: ncs5k-mcast-2.1.0.0-r653
  5001-B.txt: ncs5k-mgbl-3.0.0.0-r653
  5001-B.txt: ncs5k-k9sec-3.1.0.0-r653 540-A.txt:Sun Jun 23 07:29:10.954 UTC  &lt;---
  540-A.txt: Active Packages: 10
  540-A.txt: ncs540-xr-6.3.2 version=6.3.2 [Boot image]
  540-A.txt: ncs540-mpls-1.0.0.0-r632
  </code></pre>