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Print a date from 3 days ago
This command prints the Date (Not time) from 3 days ago (72 hours ago). This works on systems without GNU date (MacOSX , Solaris, FreeBSD).

Sum columns from CSV column $COL
More of the same but with more elaborate perl-fu :-)

Rename files in batch

read Windows ACLs from Linux
You can read, add, delete and modify Windows permissions from Linux using smbcacls from the smb-client package.

count of down available ips
avoid wc overload ;)

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Delete Last Line of a File if it is Blank
Use sed to remove the last line of a file only if it is empty.

Check ps output to see if file is running, if not start it
This comes in handy if you have daemons/programs that have potential issues and stop/disappear, etc., can be run in cron to ensure that a program remains up no matter what. Be advised though, if a program did core out, you'd likely want to know why (gdb) so use with caution on production machines.

Get AWS temporary credentials ready to export based on a MFA virtual appliance
You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials


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