Usefull Linux Commands

Here are bunch of usefull linux commands.

i) Remove files by last updated date.
This will remove the files older than the "ctime" arg, in the current directory.
(note this is an interview question)

find  -ctime +17 -daystart -exec rm "{}" \;

Command to Delete files created on a particular day:

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# touch -t 1104160000 /tmp/begin
# touch -t 1104172359 /tmp/end
# cd <- folder where your files are ->
# find . -xdev -type f -newer /tmp/begin -a ! -newer /tmp/end | xargs rm 

Find number of open files in system
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lsof | perl -lane '$x{"$F[0]:$F[1]"}++;END { print
"$x{$_}\t$_" for sort {$x{$a}<=>$x{$b}} keys %x}'

( Will be updated soon with more ...)