How to efficiently delete the last line or lines of a dozens of G text file under Linux

When we log or text data on the server side, sometimes there is a need to delete the last few lines of a large file, then how to efficiently implement.

Internet browsing finally found the DD command, pro-test as follows, delete a 32GB log file the last 100 lines only need 4 minutes

[[Email protected]_10 tmp]# dd Of=sqq_jobs_run.log.bak seek=1 bs=$ (($ (stat-c%s sqq_jobs_run.log.bak)-$ (tail-1 sqq_jobs _RUN.LOG.BAK|WC-C)))

Sqq_jobs_run.log.bak to manipulate the large file, Tail-n #n代表要删掉最后的几行, here is the last line to delete.

How to efficiently delete the last line or lines of a dozens of G text file under Linux