Using sed, delete from specific line until first match(not included) - sed

Question

I have some data looks like
1:Alice 2313
2:Desctop 456
3:Cook 111
4:.filename 50
...
...
100:Good 3
Dir num:10
File num:90
...
...
I want to delete all lines from specific line(ex. line 3) until the line "Dir num:" show up.
The idea output should be(according above example):
1:Alice 2313
2:Desctop 456
Dir num:10
File num:90
...
...
I have google several solutions likesed -i '/somestring/,$!d' file.
But these solutions are not suitable because of the specific line where deletion satarting.
How can I do this in 1 command without any tmp file?
Forgive my poor English, I'm not native English speaker.

Answer 1

You need to specify the address range from the specified line number (3) to the line matching the pattern (/Dir num/). However, it's not quite as simple as
sed '3,/Dir num/ d' file
because that will delete the "Dir num" line. Try this instead:
sed '3,/Dir num/ {/Dir num/! d}' file
That will, for the lines in the range, check that the line does not match the pattern: is the pattern is not matched, delete it.

Answer 2

Use the range: /pattern1/,/pattern2/ option of sed
$ sed -e '/2:Desctop 456/,/Dir num:10/{//!d}' inputFile
1:Alice 2313
2:Desctop 456
Dir num:10
File num:90
...
...