Commands by tr1234 (0)

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    bash: commands not found

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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" }

launch bash without using any letters
I don't know why anyone would use this, I was just messing around tonight and managed to start bash without using any letters and thought I would share. It's pretty simple, first it tries to execute "-" redirecting stderr to stdout which prints the error "bash: -: command not found" to standard output, then I try to execute "bash: -: command not found" which produces the output "bash: bash: -: command not found: command not found". lastly, (on the other side of the semicolon) I use the underscore environment variable which refers to the last command run ("bash: -: command not found") and take out everything after the first ":" character using brace expressions and your left with "bash"

Send multiple attachments using mailx
If you're users have ever asked your script to email their reports in separate attachments instead of tar'ring them into one file, then you can use this. You'll need the mailx package of course. In Unix you'd want to add an additional parameter "-m" (uuencode foo.txt foo.txt; uuencode /etc/passwd passwd.txt)|mailx -m -s "Hooosa!" someone@cmdfu.com

ssh batch jobs: query hundreds of hosts with an ssh command
Need to query hundreds of hosts with an ssh command ? Of course you'll have setup keys on all your remote HOSTs. But in the case a key is not present this command will skip that node, proceeding on to the next. -t: Force pseudo-tty allocation. This can be used to execute arbitrary screen-based programs on a remote machine. Also prevents unwanted stty messages being sent to console -q: Quiet mode. -o "BatchMode yes" If set to yes, passphrase/password querying will be disabled. This option is useful in scripts and other batch jobs where no user is present

Find the package that installed a command

Find the package that installed a command

Validate and pretty-print JSON expressions.
You can use a site like http://www.jsonlint.com/ or use the command line to validate your long and complex json data. This is part of the simplejson package for python http://undefined.org/python/#simplejson. Wrong json expression example: $ echo '{ 1.2:3.4}' | python -m simplejson.tool Expecting property name: line 1 column 2 (char 2)

Monitor TCP opened connections

Get the number of days in a given month and year

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