Tip #205   Convert permissions to octal

Converts the symbolic permissions to octal (ie: numbers) when using 'ls -l':

Read more »

Tip #204   Find matching programs

Sometimes you want to find a program without knowing the full name. This can be done with the following one liner:

IFS=: ; for D in $PATH; do for F in $D/*PATTERN*; do [ -x $F ] && echo $F; done; done

For example:
Read more »

Tip #201   Store a directory name to come back to

Put the following alias in your profile to store a directory name to use later on:
Read more »

Tip #200   Pushd and Popd

Use pushd and popd to store directories to go back to later:

Read more »

Tip #199   Find files by modified time

When specifying time with find options such as -mmin (minutes) or -mtime (24 hour periods, starting from now), you can specify a number n to mean exactly n, -n to mean less than n, and +n to mean more than n. 2 For example:

Read more »

Tip #198   vimdiff and svn

vimdiff <(svn cat -r ##ver## foo) foo

will put you in the usual vimdiff output, but comparing between ##ver## and your current version of foo Read more »

Tip #197   Zero files

Zero out files leaving directory and file sets in place - used for archival purposes.
Read more »

Tip #196   Manipulate Bash sockets using /dev/tcp

Don't have telnet or netcat handy for making a socket connection? Most Linux distros - not likely Debian - have this functionality built directly into Bash. The following will pull my site's index source on port 80, replace with any URL.

Read more »

Tip #195   Bash

These handy one-liners are used to perform the famous Caesar cipher encryption where letters of the alphabet are shifted by differing margins. The same tr command can be used to encrypt and decrypt encoded files/strings.

Rot-13 encryption:
(file)
Read more »

Tip #194   Fix the previous command

If, like me, you often make mistakes on the command line, try using the history shortcut '^^' to repeat the last command with changes.

For example:

Read more »