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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" }

give a binary the ability to open ports below 1024 as non root user
Binding a server to privileged port on Linux w/o running as root This is applicable to any service using privileged ports (< 1024), for instance to run a HTTP server on port 80 or a LDAP directory server on port 389 for example.

Get CPU thermal data on MacOS

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

Go to the previous sibling directory in alphabetical order
Based on linkinpark342 suggestion. Sometimes you have to browse your way through a lot of sub-directories. This command cd to the previous sub-directory in alphabetical order. For example, if you have the directories "lectures/01-intro", "lectures/02-basic", "lectures/03-advanced" and so on, and your PWD is "02-basic", it jumps to "01-intro".

generate a randome 10 character password

Change size of lots of image files.
Imagemagick library is used.

find sparse files
Prints the path/filename and sparseness of any sparse files (files that use less actual space than their total size because the filesystem treats large blocks of 00 bytes efficiently).

Quickly generate an MD5 hash for a text string using OpenSSL

Check variable has been set


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