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Monitor a file with tail with timestamps added
This is useful when watching a log file that does not contain timestamps itself. If the file already has content when starting the command, the first lines will have the "wrong" timestamp when the command was started and not when the lines were originally written.

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" }

Show a Package Version on RPM based distributions
if you want to see all information about a package use: rpm -qi pkgname full list of querytags can be accessed by the command: rpm --querytags you can also customize the query format how ever you like with using more querytags together along with escape sequences in "man printf"! you can also use more than one package name. for example this command shows name and version in to columns: rpm -q --queryformat %-30{NAME}%{VERSION}\\n pkg1 pkg2

Forward port 8888 to remote machine for SOCKS Proxy
Simply change your web browser's proxy settings to point to a SOCKS proxy at port 8888 and you're good to go.

Recurse through directories easily
This is a simple case of recursing through all directories, adding the '.bak' extension to every file. Of course, the 'cp $file $file.bak' could be any code you need to apply to your recursion, including tests, other functions, creating variables, doing math, etc. Simple and clean recursion.

Synchronize date and time with a server over ssh
Set Remote Server Date using Local Server Time (push)

log a command to console and to 2 files separately stdout and stderr

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

Rename files in batch


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