crontab has a resolution of 1 minute. If you're fine with lag time accumulating per that minute and then resetting on the next minute, this basic idea could work:

* * * * * for second in $(seq 0 59); do /path/to/script.sh & sleep 1s;done

Note that script.sh is also run in the background. This should help to minimize the lag that accumulates with each iteration of the loop.

Depending on how much lag sleep generates, there is however the chance of second 59 overlapping with second 0 of the next minute.

crontab has a resolution of 1 minute. If you're fine with lag time accumulating per that minute and then resetting on the next minute, this basic idea could work:

* * * * * for second in $(seq 0 59); do /path/to/script.sh & sleep 1s;done

Note that script.sh is also run in the background. This should help to minimize the lag that accumulates with each iteration of the loop.

Depending on how much lag sleep generates, there is however the chance of second 59 overlapping with second 0 of the next minute.

EDIT to toss in some results, in the same format as in the question:

$ cat timelog-cron
2012-07-16 20:51:01
...
2012-07-16 22:43:00

1 hour 52 minutes = 6720 seconds

$ wc -l timelog-cron
6720 timelog-cron

0 timing problems, 0% off. Any time accumulation resets every minute.