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Show a git log with offsets relative to HEAD
Print a git log (in reverse order) giving a reference relative to HEAD. HEAD (the current revision) can also be referred to as HEAD~0 The previous revision is HEAD~1 then HEAD~2 etc. . Add line numbers to the git output, starting at zero: $ ... | nl -v0 | ... . Insert the string 'HEAD~' before the number using sed: $ ... | sed 's/^ \+/&HEAD~/' . Thanks to bartonski for the idea :-)

Check command history, but avoid running it
!whatever will search your command history and execute the first command that matches 'whatever'. If you don't feel safe doing this put :p on the end to print without executing. Recommended when running as superuser.

Display a block of text: multi-line grep with perl
-n reads input, line by line, in a loop sending to $_ Equivalent to while () { mycode } -e execute the following quoted string (i.e. do the following on the same line as the perl command) the elipses .. operator behaves like a range, remembering the state from line to line.

Sort movies by length, longest first
handles file names with spaces and colons, fixes sort (numeric!), uses mplayer, same output format as other alternatives

check open ports without netstat or lsof

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"

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" }

create new branch from stashed changes
from http://git-scm.com/book/en/Git-Tools-Stashing Useful for when stash cannot be applied to current branch

execute your commands hiding secret bits from history records
$ wget --user=username --password="$password" http://example.org/ Instead of hiding commands entirely from history, I prefer to use "read" to put the password into a variable, and then use that variable in the commands instead of the password. Without the "-e" and "-s" it should work in any bourne-type shell, but the -s is what makes sure the password doesn't get echoed to the screen at all. (-e makes editing work a bit better)

Search big files with long lines
This is a handy way to circumvent the "Maximum line length of 2048 exceeded" grep error. Once you have run the above command (or put it in your .bashrc), files can be searched using: $ lgrep search-string /file/to/search


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