based in part on savelog in debianutils

A shell script for writing and rolling logs.

Plop the script in your bin directory or on your PATH somewhere. It requires bash.

This script writes out standard input to a specified log file, but also handles rolling over old copies of the log file each time it is run. Use it instead of redirecting to a log file; instead of:

<command> > output.log

do this:

<command> | logs output.log

This script runs as long as standard input can be read, so when the feeding command exits, it does too.

When this script starts, it renames old logs, keeping up to a maximum number (default 10) around, with the oldest having the highest number in its name. The sequence is:

output.log -> output.log.0.gz -> output.log.1.gz -> ... -> output.log.n-1.gz

By default, old logs are compressed using gzip, but different compression or none at all may be employed.

Run the script with -h to see all the available options.

• If a new log directory is chosen between runs, log rotation starts over. Logs in the old log directory are left alone.
• If the maximum count is reduced between runs, old logs with numbering greater than one less than the new maximum count are not removed.
• The compression tool must be able to take in the file to compress as its sole argument, and compress it in place. gzip, bzip2, xz, and compress all qualify.
• The user, group, and mode of old log files are never changed.