Commands by JustinHop (1)

  • Use the command watch, which is really hard to pass nested quotes to, and insert newlines where they are supposed to go in the HTTP request. that is after 1.1 after the host and two newlines at the end before the EOF. i use this all day what? no support for HEREDOCs on commandlinefu's interface? need more fu. Show Sample Output

    watch -n 1 nc localhost 80 '<<EOF GET / HTTP/1.1 Host: tux-ninja Connection: Close EOF'
    JustinHop · 2009-08-06 23:20:31 0

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Format partition with ext4 but without a journal
For slow flash memory (cheap thumb drive), ext4 is the fastest stable file system for all use cases with no relevant exception: Since we can usually dispense with the benefits of a journal for this type of storage, this is a way to achieve the least awful I/O-speed. Disabling the journal for an existing ext4 partition can be achieved using $ tune2fs -O ^has_journal /dev/sdXN Note that it is often recommended to format removable flash media with ext2, due to the lack of a journal. ext4 has many advantages over ext2 even without the journal, with much better speed as one of the consequences. So the only usecase for ext2 would be compatibility with very old software.

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" }

Click on a GUI window and show its process ID and command used to run the process
This command is useful when you want to know what process is responsible for a certain GUI application and what command you need to issue to launch it in terminal.

Stream (almost) any music track in mplayer
Just give it an artist and/or song at the end of the command as shown. - CLI alternative to
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Output a SSL certificate start or end date
A quick and simple way of outputting the start and end date of a certificate, you can simply use 'openssl x509 -in xxxxxx.crt -noout -enddate' to output the end date (ex. notAfter=Feb 01 11:30:32 2009 GMT) and with the date command you format the output to an ISO format. For the start date use the switch -startdate and for end date use -enddate.

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

Search for packages, ranked by popularity
This will take the packages matching a given `apt-cache search` query (a collection of AND'd words or regexps) and tell you how popular they are. This is particularly nice for those times you have to figure out which solution to use for e.g. a PDF reader or a VNC client. Substitute "" for "" if you want this to use Ubuntu's data instead. Everything else will work perfectly.

tell if a port is in use
if you don't do --numeric-ports, netstat will try to resolve them to names

Swap a file or dir with quick resotre
This lets you replace a file or directory and quickly revert if something goes wrong. For example, the current version of a website's files are in public_html. Put a new version of the site in public_html~ and execute the command. The names are swapped. If anything goes wrong, execute it again (up arrow or !!).

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