How can I limit the size of a log file, which is saved in the form of 'foo.txt', from within a bash script please? I want to put in the variables 'LOGFILE=50 mb' and it uses that size, or whatever size LOGFILE is.
This is on Debian 7, fully up-to-date.
You need to use logrotate. Do something like this
cat /etc/logrotate.conf
/path/foo.txt {
size 50M
create 700 root root
rotate 5
}
size 50M – logrotate runs only if the filesize is equal to (or greater than) this size.
create – rotate the original file and create the new file with specified permission, user and group.
rotate – limits the number of log file rotation. So, this would keep only the recent 5 rotated log files.
I used tail to do that. It's more of a quick and dirty solution respect to logrotate, but it does the job.
Here's what I put in my script:
# in the preceding lines, the log file is updated, with new content at the
# bottom.
# every update causes the file to exceed the size limit (set to 1MB)
# using tail, put the last 1MB of the file in a temporary file
/usr/bin/tail -c 1MB /your/path/here/logfile.log > /your/path/here//temp 2>&1
# overwrite the older and oversized log file with the new one
/bin/mv /your/path/here/temp /your/path/here/logfile.log
Something like that?
LF=foo.txt
typeset -i LFSB LFSM LOGFILE=50
let LFSB=$(stat -c "%s" $LF)
# This is bytes - turn into MB, base 2
let LFSM=${LFSB}/1048576
if [ $LFSM -gt $LOGFILE ]
then
echo Logfile $LF is greater than $LOGFILE MB
else
echo Logfile $LF is less or equal than $LOGFILE MB
fi
