sed one-liners

sed 's/ Телефон: /\t/' filename             # basic search and replace

sed 's/ [-] .*//' filename                       # put tricky chars in []

sed 's/\&amp/\&/' filename                  # example of escaped char

sed 's/.\{1\}/& /g' filename                   # insert 1 space between each char

sed 's/.\{2\}/& /g' filename                   # insert 2 spaces between each char

sed 's/\(.*\)\/word$/word\1/' filename     # search and replace with a captured pattern () on LHS and \1 on RHS

sed 's/word/&\n/' filename                   # search and replace insert a newline
sed '/^\s*$/d' filename                         # delete blank line

Good resources for one-liners with examples http://sed.sourceforge.net/sed1line.txt

using "screen" command to handle multiple sessions

from http://www.cyberciti.biz/tips/linux-screen-command-howto.html


$ screen -S 1
CTRL+a, c            -- create another screen window
CTRL+a, n            -- switch to next screen window I've got open

• 
  To list all windows use the command CTRL+a followed by " key (first hit CTRL+a, releases both keys and press " ).
• To switch to window by number use the command CTRL+a followed by ' (first hit CTRL+a, releases both keys and press ' it will prompt for window number).

Common screen commands

screen command	Task
Ctrl+a c	Create new window
Ctrl+a k	Kill the current window / session
Ctrl+a w	List all windows
Ctrl+a 0-9	Go to a window numbered 0 9, use Ctrl+a w to see number
Ctrl+a Ctrl+a	Toggle / switch between the current and previous window
Ctrl+a S	Split terminal horizontally into regions and press Ctrl+a c to create new window there
Ctrl+a :resize	Resize region
Ctrl+a :fit	Fit screen size to new terminal size. You can also hit Ctrl+a F for the the same task
Ctrl+a :remove	Remove / delete region. You can also hit Ctrl+a X for the same taks
Ctrl+a tab	Move to next region
Ctrl+a D (Shift-d)	Power detach and logout
Ctrl+a d	Detach but keep shell window open
Ctrl-a Ctrl-\	Quit screen
Ctrl-a ?	Display help screen i.e. display a list of commands

Suggested readings:

See screen command man page for further details:
man screen

awk

specify tab-delimited columns
awk -F'\t' '{ print $1}' file

print column $13 and column $10 where $13 matches "MY"
awk -F"\t" '$13 ~ /MY/ {print $13"\t"$10}' | less

awk -F"\t" '$7 == "restaurant" ' japan.osm.poi  > restaurants


awk '{ print \$1} ' file,   print 1st column, escape $ when in perl system command



not really sure what this does.....

awk -F "\"*,\"*" '{print $3"\t"$5}' jigyosyo.csv

my .bashrc file

So you don't have to do source ~/.bashrc every time you open a terminal, put it in ~/.bash_profile.
~> cat .bash_profile
source ~/.bashrc


Things I like to have in my .bashrc file are:
.... in progress

file transfer

If you're transferring between Windows and linux, use winSCP.

If you're transferring linux to linux use scp like this:

>> scp ......

Perl one-liners

• Read line, substitute regex and print line.
• perl  -ne '{$l = $_; $l=~ s/dede/frfr/g; print $l;}' input1.txt
• perl –ne ‘$l = $l =~ s/dede/frfr/g; print $l;}’ input1.txt input2.txt
• -e means “execute” and –n makes it loop line by line
• Multiple input files are fine.

• Snazzier replacement per line


• perl  -pe 's/a/b/g' < input > newfile

• Read line and print the (1-indexed) line number and line.
• perl –ne ‘print “$. – $_”’ input1.txt
• output looks like:
• 1 – My first line of input text
• 2 – My second line of input text

• With no input, print 0 to 999
• perl -e ' for ($i=0;$i<999;$i++) { print "$i\n"}  '

THESE DON'T WORK WELL WITH sed

perl -pe "s/\&apos/'/g" < 2.2_cleaner > new

perl -pe 's/\&quot/"/g' < 2.2_cleaner > new

using tar to compress and extract files

 

Using tar to compress file(s)

• tar –czvf destination.tar.gz source/*

Using tar to uncompress/extract file(s) 

• tar –xzvf destination.tar.gz

where:
c = create a new tar file
v = verbose , display file to compress or uncompress
f = create the tar file with filename provided as the argument
z = use gzip to zip it
x = extract file