Force flushing of output to a file while bash script is still running

bash file flush
olamundo picture olamundo · Sep 16, 2009 · Viewed 113.4k times · Source

I have a small script, which is called daily by crontab using the following command:

/homedir/MyScript &> some_log.log

The problem with this method is that some_log.log is only created after MyScript finishes. I would like to flush the output of the program into the file while it's running so I could do things like 

tail -f some_log.log

and keep track of the progress, etc.

Answer

Martin Wiebusch picture Martin Wiebusch · Jun 15, 2015

I found a solution to this here. Using the OP's example you basically run

stdbuf -oL /homedir/MyScript &> some_log.log

and then the buffer gets flushed after each line of output. I often combine this with nohup to run long jobs on a remote machine.

stdbuf -oL nohup /homedir/MyScript &> some_log.log

This way your process doesn't get cancelled when you log out.

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