vi and vim commands

Command mode ESC

                dd       delete
                u        undelete
                y        yank (copy to buffer)
                p/P      p before cursor/P after cursor

                Ctl-g    show current line number
                shft-G   end of file
              n shft-G   move to line n

               /stuff/   search
                  n   repeat in same direction
                  N   repeat in opposite direction
                  /return  repeat seach forward
                  ?return  repeat seach backward

               "dyy  Yank current line to buffer d
               "a7yy Yank next 7 lines to buffer a
                    or
               :1,7ya a  Yank [ya] lines 1,7 to buffer a
               :1,7ya b  Yank [ya] lines 1,7 to buffer b

               :5 pu b   Put [pu] buffer b after line 5

               "dP   Put the content of buffer d before cursor
               "ap   Put the contents of buffer a after cursor

               :1,4 w! file2  Write lines 1,4 to file2
               :1,3

               :set nu     Display line numbers
               :set nonum  Turns off display

               :set ic     Ignore Case

               :e  Edit a file in a new buffer

               :g//p   Print matching regular expression

            vim
               :split
               :split 
               :sp 
               :split new

                   ctl-w   To move between windows
                   ctl-w+
                   ctl-w-  To change size
                   ctl+wv  Split windows vertically
                   ctl-wq  Close window

               :only       To view only 1 window

            vim dictionary - put the following command in ~/.vimrc

                   set dictionary+=/usr/share/dict/words
                   set thesaurus+=/usr/share/dict/words
              
               Now, after you type a word  and to 
               go back in the listing 

                   butter

           Scripting - you can script vi commands using ex. For example
               suppose you want to replace all occurrences of "one" with "two", then
               exit the file if there are changes. You would put the following in a file call script

               Contents of script

                   %s/one/two/g|x

               If you want to run this on all files with the patten "example*"

                   for i in $(ls example*); do ex - $i 

What Network Services are Running

$ netstat -tanup

     or if you just want tcp services
 
          $ netstat -tanp

     or

          $ netstat -ap|grep LISTEN|less

     This can be helpful to determine the services running.

     Need stats on dropped UDP packets?

          $ netstat -s -u

     or TCP

          $ netstat -s -t

     or summary of everything

          $ netstat -s

     or looking for error rates on the interface?

          $ netstat -i

     Listening interfaces?

          $ netstat -l

awk - common awk commands.

Find device names "sd" or with major number 4 and device name "tty". Print the
     record number NR, plus the major number and minor number.

          $ awk '$2 == "sd"||$1 == 4 && $2 == "tty" { print NR,$1,$2}' /proc/devices

     Find device name equal to "sound".

          $ awk '/sound/{print NR,$1,$2}' /proc/devices

     Print the 5th record, first field, in file test

          $ awk 'NR==5{print $1}' test

     Print a record, skip 4 records, print a record etc from file1

          $ awk '(NR-1) % 4 == 0 {print $1}' file1

     Print all records except the last one from file1

          $ tac file1|awk 'NR > 1 {print $0}'|tac

     Print A,B,C ..Z on each line, cycling back to A if greater than 26 lines

          $ awk '{ print substr("ABCDEFGHIJKLMNOPQRSTUVWXYZ",(NR-1)%26+1,1),$0}' file1

     Number of bytes in a directory.

          $ ls -l|awk 'BEGIN{ c=0}{ c+=$5} END{ print c}'

     Remove duplicate, nonconsecutive line. As an advantage over "sort|uniq"
     you can eliminate duplicate lines in an unsorted file.

          $ awk '! a[$0]++' file1

     Or the more efficient script

          $ awk '!($0 in a) {a[$0];print}' file1

     Print only the lines in file1 that have 80 characters or more

          $ awk 'length < 80' file1

     Print line number 25 on an extremely large file -- note it has
     to be efficient and exit after printing line number 25.

          $ awk 'NR==25 {print; exit}'  verybigfile

Using the "find" Command.

List only directories, max 2 nodes down that have "net" in the name

       $ find /proc -type d -maxdepth 2 -iname '*net*'

     Find all *.c and *.h files starting from the current "." position.

       $ find . \( -iname '*.c'  -o -iname '*.h' \) -print

     Find all, but skip what's in "/CVS" and "/junk". Start from "/work"


       $ find /work \( -iregex '.*/CVS'  -o -iregex '.*/junk' \)  -prune -o -print

     Note -regex and -iregex work on the directory as well, which means
     you must consider the "./" that comes before all listings.

     Here is another example. Find all files except what is under the CVS, including
     CVS listings. Also exclude "#" and "~".

       $ find . -regex '.*' ! \( -regex '.*CVS.*'  -o -regex '.*[#|~].*' \)

     Find a *.c file, then run grep on it looking for "stdio.h"

       $ find . -iname '*.c' -exec grep -H 'stdio.h' {} \;
         sample output -->  ./prog1.c:#include 
                            ./test.c:#include 

     Looking for the disk-hog on the whole system?

       $ find /  -size +10000k 2>/dev/null

     Looking for files changed in the last 24 hours? Make sure you add the
     minus sign "-1", otherwise, you will only find files changed exactly
     24 hours from now. With the "-1" you get files changed from now to 24
     hours.


       $ find  . -ctime -1  -printf "%a %f\n"
       Wed Oct  6 12:51:56 2010 .
       Wed Oct  6 12:35:16 2010 Linux_and_Open_Source.txt

     Or if you just want files.

       $ find . -type f -ctime -1  -printf "%a %f\n"

     Details on file status change in the last 48 hours, current directory. Also note "-atime -2").

       $ find . -ctime -2 -type f -exec ls -l {} \;

             NOTE: if you don't use -type f, you make get "." returned, which
             when run through ls "ls ." may list more than what you want.

             Also you may only want the current directory

       $ find . -ctime -2 -type f -maxdepth 1 -exec ls -l {} \;

     To find files modified within the last 5 to 10 minutes

       $ find . -mmin +5 -mmin -10