Log Rotate based on filesize with Timestamp of lines, open source C code (Apache License, Version 2.0). Do not require any external code/lib.

Read from stdin and output lines with timestamp in an output file (pathname), rotating them when file size exceeds specified size in bytes.

gcc -Wall -O2 logrotate.c -o logrotate

./process-to-log | ./logrotate <pathname> <size-limit-bytes>

2013-06-02 00:47:51 > Lorem ipsum dolor sit amet, consectetur adipiscing elit.
2013-06-02 00:47:51 > Pellentesque in mi ac tellus porttitor condimentum.

Inspired in rotatelogs and cronolog, this is C-minimalistic version.