[linux] How to file split at a line number

I want to split a 400k line long log file from a particular line number.

For this question, lets make this an arbitrary number 300k.

Is there a linux command that allows me to do this (within the script)?

I know split lets me split the file in equal parts either by size or line numbers but that's not what I want. I want to the first 300k in one file and the last 100k in the second file.

Any help would be appreciated. Thanks!

On second thoughts this would be more suited to the superuser or serverfault site.

This question is related to linux shell split filesplitting

The answer is


file_name=test.log

# set first K lines:
K=1000

# line count (N): 
N=$(wc -l < $file_name)

# length of the bottom file:
L=$(( $N - $K ))

# create the top of file: 
head -n $K $file_name > top_$file_name

# create bottom of file: 
tail -n $L $file_name > bottom_$file_name

Also, on second thought, split will work in your case, since the first split is larger than the second. Split puts the balance of the input into the last split, so

split -l 300000 file_name

will output xaa with 300k lines and xab with 100k lines, for an input with 400k lines.


Examples related to linux

grep's at sign caught as whitespace How to prevent Google Colab from disconnecting? "E: Unable to locate package python-pip" on Ubuntu 18.04 How to upgrade Python version to 3.7? Install Qt on Ubuntu Get first line of a shell command's output Cannot connect to the Docker daemon at unix:/var/run/docker.sock. Is the docker daemon running? Run bash command on jenkins pipeline How to uninstall an older PHP version from centOS7 How to update-alternatives to Python 3 without breaking apt?

Examples related to shell

Comparing a variable with a string python not working when redirecting from bash script Get first line of a shell command's output How to run shell script file using nodejs? Run bash command on jenkins pipeline Way to create multiline comments in Bash? How to do multiline shell script in Ansible How to check if a file exists in a shell script How to check if an environment variable exists and get its value? Curl to return http status code along with the response docker entrypoint running bash script gets "permission denied"

Examples related to split

Parameter "stratify" from method "train_test_split" (scikit Learn) Pandas split DataFrame by column value How to split large text file in windows? Attribute Error: 'list' object has no attribute 'split' Split function in oracle to comma separated values with automatic sequence How would I get everything before a : in a string Python Split String by delimiter position using oracle SQL JavaScript split String with white space Split a String into an array in Swift? Split pandas dataframe in two if it has more than 10 rows

Examples related to filesplitting

How to file split at a line number