Commands using iptables (39)

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Write comments to your history.
A null operation with the name 'comment', allowing comments to be written to HISTFILE. Prepending '#' to a command will *not* write the command to the history file, although it will be available for the current session, thus '#' is not useful for keeping track of comments past the current session.

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Are the two lines anagrams?
This is just a slight alternative that wraps all of #7917 in a function that can be executed

check open ports without netstat or lsof

Convert seconds to [DD:][HH:]MM:SS
Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

List and delete files older than one year

Rsync using SSH and outputing results to a text file
--delete will delete copies on remote to match local if deleted on local --stats will output the results -z zip -a archive -A preserve ACL -x don't cross filesystem boundaries -h human readable -e specify the remote shell to use

Show bandwidth use oneliner
poorman's ifstat using just sh and awk. You must change "eth0" with your interface's name.

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Find Duplicate Files (based on size first, then MD5 hash)
This dup finder saves time by comparing size first, then md5sum, it doesn't delete anything, just lists them.

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