Commands by xsawyerx (6)

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Quickly create simple text file from command line w/o using vi/emacs
1. Issue command 2. After angled bracket appears, enter file contents 3. When done, type "EOF"

(Debian/Ubuntu) Discover what package a file belongs to
'dpkg -S' just matches the string you supply it, so just using 'ls' as an argument matches any file from any package that has 'ls' anywhere in the filename. So usually it's a good idea to use an absolute path. You can see in the second example that 12 thousand files that are known to dpkg match the bare string 'ls'.

Massive change of file extension (bash)
Change the file extension in batch. Useful to create output file names with same input name but distinct extension by including logic inside the loop

Submit command & rewrite orginal command
Similar to entering a command, but will not erase the command from the command line. Basically a shortcut from entering command, then pushing the up arrow key.

See a full list of compiler defined symbols
From http://lists.debian.org/debian-devel/2001/01/msg00971.html .

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"

sends a postscript file to a postscript printer using netcat

Remove duplicate lines whilst keeping empty lines and order
Remove duplicate lines whilst keeping order and empty lines

List alive hosts in specific subnet
Works on any machine with nmap installed. Previous version does not work on machines without "seq". Also works on subnets of any size.

Create a backup of file being edited while using vi
At the start of a vi session and *before* saving any changes use ":!cp % %-" to make a backup of the current file being edited. example: vi /data/some/long/path/file :!cp% %- creates /data/some/long/path/file-


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