bash - Delete all lines before first occurrence of specific string in file

Question

Basically I have a file like:

junk
morejunk
somestring
bats
car
somestring
bats
car
somestring
bats
car

and I want to remove all of the junk before the first occurrence of somestring so the file looks like

somestring
bats
car
somestring
bats
car
somestring
bats
car

I followed the advice from this question to use sed -i '0,/somestring/,d' file.txt but it deletes the line with the first occurrence of somestring, when I want to keep that line as the first line.

Answer 1

With sed you could use:

sed -i '/somestring/,$!d' file

Explanation of replace expressions:

_{, matches lines starting from where the first address matches, and continues until the second match (inclusively).}

_{$ matches the last line of the last file of input, or the last line of each file when the -i or -s options are specified.}

_{! If the character follows an address range, then only lines which do not match the address range will be selected.}

_{d Delete the pattern space; immediately start next cycle.}

Result:

$ sed -i '/somestring/,$!d' file
somestring
bats
car
somestring
bats
car
somestring
bats
car