Commands tagged #magic (1)

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Jump to a directory, execute a command and jump back to current dir

Adding Prefix to File name
Good old bracket expansion :-) For large numbers of files, "rename" will spare you the for-loop, or the find/exec...

openssl Generate Self Signed SSL Certifcate
generating self signed ssl certificate to use in dovecot postfix nginx Self signed certificates can be used for private encryptions between server and client and must be manually accepted on browser/ client

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" }

Download a file securely via a remote SSH server
This command will download $file via server. I've used this when FTP was broken at the office and I needed to download some software packages.

Remote backups with tar over ssh
Execute it from the source host, where the source files you wish backup resides. With the minus '-' the tar command deliver the compressed output to the standar output and, trough over the ssh session to the remote host. On the other hand the backup host will be receive the stream and read it from the standar input sending it to the /path/to/backup/backupfile.tar.bz2

Do one ping to a URL, I use this in a MRTG gauge graph to monitor connectivity

View Owner, Group & Permissions.
#Alias alias perm="stat -c '%n %U:%G-%a'" #Function perm() { for ll in $@; do stat -c "%n %U:%G-%a" "$ll"; done; }

Extract the MBR ID of a device
Useful when you want to know the mbrid of a device - for the purpose of making it bootable. Certain hybridiso distros, for eg the OpenSUSE live ISO uses the mbrid to find the live media. Use this command to find out the mbrid of your USB drive and then edit the /grub/mbrid file to match it.

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"

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