Shell Programming and Scripting

Could someone please tell me how to delete all lines above a line which contains a particular string? (possibly using SED command)
I know how to do this if the target string appears in only one line of file but when it appears in multiple lines it only deletes from the first line which the string appears to the top line. I want it to delete from the last line which the string appears to the top line.


e.g I have the file below which contains 8 lines:

Code:

$ cat file.txt
a
b
c
d
a
b
c
d
$

I want to delete everything above the line with the charater "b" to get the below:

Code:

c
d

I tried with the command below but it only deleted line from the top to the first line which contains the charater "b"

sed '1,/b/d' file.txt

Regards,
Steve

not 'exactly' sed (could not make sed 'greedy' enough), but:

Code:

nawk -v pat='b' '$0 ~ pat { a=""; next}; {a=(!length(a) ? $0 : a RS $0) }; END { print a }' myFile.txt

Code:

sed -n -e ":a" -e "$ p;N;/b/d;b a" file

Thanx anbu23 and vgersh99!!