SMTP: Using smtp commands in a shell script when sendmail isn't setup.

LOG="/tmp/${0##*/}.log"

SUBJECT="${0##*/}"

MAILSERVER=mailhost

PORT="25"

MAILFROM="user1@domain user2@domain"

MAILLIST="email@somedomain"

#------------------------------------------------------------------------

mailto()

{

exec 3<>/dev/tcp/$MAILSERVER/$PORT

if [ $? -ne 0 ]

then

echo

echo "ERROR: Cannot connect to the Mail Server"

echo "Please check the servername and/or the port number"

exit

fi

echo -en "HELO ${MAILSERVER}\r\n" >&3

echo -en "MAIL FROM:$MAILFROM\r\n" >&3

for MAILTO in ${MAILLIST}

do

echo -en "RCPT TO:$MAILTO\r\n" >&3

done

echo -en "DATA\r\n" >&3

echo -en "Subject: $SUBJECT\r\n\r\n" >&3

echo -en "$(cat ${LOG})\r\n" >&3

echo -en ".\r\n" >&3

echo -en "QUIT\r\n" >&3

cat <&3

}

#------------------------------------------------------------------------

Some commands

.

.

mailto

AD group member listing.

List member of a AD group from XP

net group G_UNIX_SCHED /domain

or list user attributes.

net user <user id> /domain

Awk: Using getline to read a file in BEGIN

Example reading in the password file into an array for later use.

BEGIN {

        FS=":";

        while ((getline  < "/etc/passwd")  >;0 )

        {

                Alias[$1]=$0;

        }

}

Shell Scripting: basename variable

"${0##*/}" is the equivalent of "basename $0".
I.e. From /usr/bin/sh we get just sh.


Also try this to execute commands $(shell command)

Perl script options

Using getopt in perl scripts.
Sample code

#!/usr/bin/perl
#-------------------------------------------------------------------------
#       Using getop
#-------------------------------------------------------------------------
use Getopt::Std;
getopt('cw');
my @op = `./x.sh -c $opt_c -w $opt_w`;
foreach (@op)
{
        #printf "-c %s\t-w %s\n", $opt_c,$opt_w;
        print $_;
}

Output

./x.pl -c 3 -w 55

in ./x.sh.sh : -c 3 -w 55

-c 3

-w 55

or

my %options=();

#Pre set default values 

my $critv=95;
my $warnv=85;
getopts("c:w:", \%options);
$critv = $options{c} if defined $options{c};
$warnv = $options{w} if defined $options{w};

This method won't report an error if an option is emitted.

awk convert time string to time format

This will take a time string HHMMSS (121525) and format it as 12:15:25

A sample line from a.txt:

01201 095440 sd10 3393.2 1.1 13572.8 4.4 0.0 1.0 0.3 2 91

awk '{h=substr($2,1,2);\
      m=substr($2,3,2);\
      s=substr($2,5,2);\
      $2=sprintf("%s:%s:%s",h,m,s);\
      print $0;}' a.txt | head 

Will produce the following out put:

101201 09:54:40 sd10 3393.2 1.1 13572.8 4.4 0.0 1.0 0.3 2 91

Midnight commander

Startup Midnight commander with each panel in a pre-detirmined location.

mc /tmp /#ftp:guest@remote-host.com/pub/dir

Using awk to remove path and print file date

$ls -lat /current/*xml | \
         nawk '{printf "%s ", $8; system("basename " $9)}'

20:24 file1.xml

21:44 file2.xml

22:34 file3.xml
$

Translate upper case to lower case with vim

Translate upper case to lower case with vim.

:%s/[A-Z]/\L&/g

or

:%s/.*/\L&/

vi: Appending text to the end of each line

Appending text to the end of each line.

:%s/$/TextYouWantToAppend/

Add users from copied passwd file

for U in $(awk -F":" '{print $1}' passwd)
do
      echo "________________ $U __________________"
      UDIR=$(awk -F":" "/$U/"'{print $6}' passwd)
      mkdir $UDIR
      chown $U $UDIR
done

Simple compiling with gcc

Having trouble with a simple compile:

gcc -o data data.c
/tmp/ccCAfDR5.o: In function `main':
data.c:(.text+0x4c): undefined reference to `exp'
collect2: ld returned 1 exit status

Then:

gcc -lm -o data data.c

And it works, because math.h is just a header file and you need to link with the math's library.

rsync with ssh between servers

Rsync quicky with ssh between servers.

rsync -av -n source dir/ server:/target dir -n for testing. nothing happens.

rsync -av source dir/ server:/target dir -n removed. Do it for real.

Also note:
Source dir has a "/" after it to copy its contents and not the directory itself.

Rsync installed in a different location on the remote host:

rsync --rsync-path=/opt/csw/bin/rsync -av -n source dir/ server:/target

Perl. Replace text in file.

Substitute text in a file in-situ

perl -i -pe 's/1234/4321/g' filename

-i edits file in-situ.
-p loops through each filename and prints out each line.

Convert Upper case to lower case

perl -i -pe 'tr/A-Z/a-z/' x

Shell scripting: case statement & numbers

Selecting a numeric range with the case statement.

case ${NUMBER} in
        [0-9]|[0-6][0-9]|7[0-5])
                                echo "${NUMBER} <= 75"
       ;;
       [7-8][0-9]|9[0-5])
                               echo "75 < ${NUMBER}<=95"
       ;;
       [9][5-9]|100)
                                echo "95< ${NUMBER} <=100"
       ;;
esac

Shell scripting: Testing empty variables

$V="xNotEmpty"

if [ x$V = "xNotEmpty" ]
then
       echo "\$V not empty"
else
       echo"\$V is empty"
fi

Or:

if [ "$V" = "" ]
then
      echo "\$V is empty
fi

awk

Using shell variables with awk.

1. awk "/$func/"'{print $0}' filename

2. awk -v pat=$func '/pat/{print $0}' filename

Using fields in search pattern

For a similar match:

1. awk '$1~/pattern/{print $0}' filename

For a precise match:

2.  awk -F":" -v user=$U '$1 == user {print $0}' filename

Perl command line.

Using multiple perl commands on the command line.

perl -n -e 'perl cmd;'\
-e 'perlcmd'

Invoke the split command

perl -n -a -e 'cmd'

-n Places a loop around the command line.

My .vimrc file

syntax on
set viminfo^=h
set ruler
set nohls
set incsearch
set showmatch
set ts=4 sw=4
syntax enable
set hlsearch
"Use F4 to switch high lighting on/off
:noremap <F4> :set hlsearch! hlsearch<CR>

Shell Scripting: Special Variables

$?        Exit status or return code of last command.
$#        Number of arguments.
$@        Argument 1 thru n with Input Field Separator.
$*        "$1" $2" ... $n.
$!        Process id of last background process.
$$        Process id of shell running this script.
$-        The current shell flags.