How to grep the last occurrence of a line pattern

Question

I’m not sure if I got your question right, so here are some shots in the dark:

Print last occurence of x (regex):
```
grep x file | tail -1
```
Alternatively:
```
tac file | grep -m1 x
```
Print file from first matching line to end:
```
awk '/x/{flag = 1}; flag' file
```
Print file from last matching line to end (prints all lines in case of no match):
```
tac file | awk '!flag; /x/{flag = 1};' | tac
```