Text Processing: How to sort list by date delimited by a string

Question

I want to sort contents of file.txt by date. The date to sort is in the fourth table data <td></td> tag

E.g. Content of file.txt:

<tr><td>some_name_here</td><td>number_code_here</td><td>2018Mar31</td><td>2018Mar01</td></tr> <tr><td>some_name_here</td><td>number_code_here</td><td>2018Mar31</td><td>2017Jan31</td></tr> <tr><td>some_name_here</td><td>number_code_here</td><td>2018Mar31</td><td>2018Apr02</td></tr> <tr><td>some_name_here</td><td>number_code_here</td><td>2018Mar31</td><td>2017Dec25</td></tr> 

Desired output: How can I do this?

<tr><td>some_name_here</td><td>number_code_here</td><td>2018Mar31</td><td>2017Jan31</td></tr> <tr><td>some_name_here</td><td>number_code_here</td><td>2018Mar31</td><td>2017Dec25</td></tr> <tr><td>some_name_here</td><td>number_code_here</td><td>2018Mar31</td><td>2018Mar01</td></tr> <tr><td>some_name_here</td><td>number_code_here</td><td>2018Mar31</td><td>2018Apr02</td></tr> 

I've been using sort command but it's not working.

cat file.txt 2> /dev/null | sort -t'>' -k9n -k9.4M -k9.7n

EDIT: I found this reference link but still doesn't work correctly. https://stackoverflow.com/a/16060031/7842707

Answer 1

In case if each <tr> item is on a separate line:

awk + sort solution:

awk -F'[<>]' '{ print $(NF-4), $0 }' file.txt | sort -k1,1n -k1.5M | cut -d' ' -f2- 

• -F'[<>]' - treat < and > as field separator
• $(NF-4) - contains the last <td> tag value (e.g. 2017Jan31) from each row. This is used as a sorting key.
• -k1,1n - sort by the 1st field numerically (i.e. by date year)
• -k1.5M - date month sorting starting from the 5th char
• cut -d' ' -f2- - remove an auxiliary sorting key (the 1st field)

The output:

<tr><td>some_name_here</td><td>number_code_here</td><td>2018Mar31</td><td>2017Jan31</td></tr> <tr><td>some_name_here</td><td>number_code_here</td><td>2018Mar31</td><td>2017Dec25</td></tr> <tr><td>some_name_here</td><td>number_code_here</td><td>2018Mar31</td><td>2018Mar01</td></tr> <tr><td>some_name_here</td><td>number_code_here</td><td>2018Mar31</td><td>2018Apr02</td></tr>