Unix
Basics:
$ pwd ---displays current working
directory path
$ uname ----displays operating system name
Linux
$ uname –r ----displays kernel version name
3.13.0-24-generic
$ hostname -----dispalys server name
hj-glbtal8591
$ hostname
-i ----displays servers IP address
10.51.226.42
$ hostname --gives
host name
cdtssseabcd.abcorp.com
$> uptime -- #To see the server uptime, boot time, users
and load
06:11:56 up 12 days, 10:06, 110 users, load average: 71.49, 73.23, 72.12
Who is Logged In?
$ users
root
$ whoami
root
$ logname ---displays current username
$ ---user
working prompt
# ----admin working prompt
$ exit ----logout from current user account
$ su -
username ---to switch from one user to
another user account
$man
<command_name> ---gives
manual pages of acommand
$clear ----clears screen
$wc
<file_name> ---to count words, lines, bytes
$cd - ---to go to last working directory.
Viewing list of files:
$ls ---lists all files and directories in
current directory
$ls -l ---long list format
$ls -a ---list invisible files
$ls -r ----lists files in reverse order
$ls -t -------lists all files based on time
$ls
<directory_name> ---to
list files in a directory
$ls -la < directory_name
> ---to list files in a directory
$ ls
*{jpg,JPG} --lists files ending with jpg and JPG
Listing commands in current shell:
$ ls /bin
To use single
quotes in a command use back slash (\)
----------------------------------
--------------------------------------
Tab key –use this for auto completion of commands and directory names and file
names
-------------------------------------------------------
-----------------------------------------------------------
Commands:
Command details:
1)
$ cat --help
2)
$ info cat
3)
$ man cat
Cat:
For creating a
file.
$ cat >
hari -----creates hari file
$ cat <
hari ----- for opening hari file
$ cat >>
hari -----for appending the hari file
$ cat -n
<file_name> ---‘-n’ gives line number’s
How to open multiple files:
$ cat
<file1> <file2> <file3>
$cat -b
persistent ----gives line numbers
1
persistent
2
its a level 3 company
3
established in 1990
$ cat >
.<file1> ----creates
hidden file(‘.’ Is used for creating hidden files)
$ cat /dev/null
> hk_test1 --to
empty a file
Stat:
$ stat hk_test1 --gives
stats for a file
Touch:
It is used for
creating empty files, more over it is used for changing file time stamp.
$ touch
<file1> <file2> <file3>
---creates multiple files
Creating multiple files:
$ touch
memo{1,2,3,4,5}
$ ls m*
memo1 memo2 memo3
memo4 memo5
Deleting files and creating Directories:
$ rm
<file1> -----deletes
file1
$ rm –i
<file1> -----deletes
file1 with confirmation
$ rm * -----removes all files
$ mkdir
<dir_name> -----creates
dir_name directory
$ rmdir
<dirname> ----deletes
directory
$ rm -r
<dirname> -----deletes
entire directory structure even if it has files.
Copy:
$ cp
<source_file> <targetfile>
----source file must me existing and target may be new or existing
Taking backup to desired location:
cp /etc/postgresql/9.3/main/abcd.conf /root/abcd.conf_back_up
Relative path: from current directory to target
directory
Absolute path: from root directory to target
directory
MV:
To move a file or
directory (or) to rename a file or directory.
$ mv hk1
/root/hari ---hk1 is renamed to hari and moved
to root
$ mv hk1 hk2 ----hk1 is renamed to hk2
$ mv .hk1
hk1 -----hk1
hidden file is unhidden
SED:
$sed -n 2p
<file_name> ---gives
2nd line
Replacing strings using sed:
$ sed -i -e
's/PERSISTENT/psl/g' hari1 ---replaces
in hari1 file
$ sed -i -e 's/PERSISTENT/psl/g' hari1
Tr:
$ tr "
" "," < hari1 ---replaces
space with coma and opens file
PERSISTENT
ITS,A,LEVEL,3,COMPANY
ESTABLISHED,IN,1990
Vi Editor:
Vi has 2 searches
1) string 2) character
/ and ? Are used for string search
Eg: ?hari (then enter) ---searches hari string in the file
$vi –R
<file_name> ---opens
an existing file in read only mode
$view
<file_name> ----opens
an existing file in read only mode
:q! ---quit vi w/o saving
:w --save
:wq! ---save and quit from vi
cc ---removes contents of the line, leaving you in
insert mode
U ---restore current line
u ---undo thelast change to the file
:f
<filename> ---copies
current_file to filename
:e
<filename> ---opens
new file filename
:cd dirname ----changes to directory
Running commands in Vi:
Command mode à :! ls
For replacing a string in vi:
:s/pattern/replace/
:s/search/replace/g
Deleting all lines in a file in vi editor:
:1,$d
Or
:%d
Deleting specific lines in a file in vi
editor:
:4,$-2d ---leaves
first 3 and last 2 lines and deleting the rest.
:4,$d ---leaving
first3, rest of the lines are deleted.
:4,$-1d ---leaving
first 3 and last 1line, remaining are deleted
How to go to 16 line in Vi:
Esc à 16G
ESCàG ---goes to last line
How to un highlight Searched words in
Vi:
goto vi file àESC à :noh àenter
part2
Changing file Permissions:
$ chmod +x hari ---giving execution permission to hari
$chmod -111 hari ---removing execute permission from user,
group, others
Change file permissions:
Default file
permissions are 644, now we will change to 744
$ ls –l persistent
-rw-r--r-- 1 root
root 53 Jan 19 19:50 persistent ----without execution permission
$ chmod 744
persistent
$ ls -l
persistent
-rwxr--r-- 1 root
root 53 Jan 19 19:50 persistent ----execute
permissions received
$? ----gives exit status of the last
command executed
$! ---process number of the last background
command
Meta characters:
* and ? are
two meta characters.
We use * to match
zero or more characters.
The command could not be located because
'/bin' is not included in the PATH environment variable
$export PATH=/usr/bin:/bin ---works
fine with this
.bashrc
.bash_history:
Has all the
previously executed commands.
cat .bash_history
SFTP:
Getting file from another UNIX server
through sftp:
root@hj-glbtal8591:~#
sftp root@11.11.255.55 (user_id@ip_address) ---logs
into SFTP
root@10.51.225.55's
password:
Connected to
10.51.225.55.
sftp> cd
/etc/postgresql/9.3/main ---go to the folder where file is located
sftp> ls –l ---check
whether file is there or not
-rw-r----- 1 postgres postgres 4649 Oct 21 15:56 abc.conf ---file exists
-rw-r----- 1 postgres postgres 1636 Oct 20 20:01 bcd.conf
sftp> get
abc.conf ---getting
the file
Fetching
/etc/postgresql/9.3/main/abc.conf to abc.conf
/etc/postgresql/9.3/main/pg_hba.conf
100% 4649 4.5KB/s 00:00
sftp> quit ------quit
from sftp
root@hj-glbtal8591:~#
ls –l ---check whether file has come
total 2 ---total
no:of files in that particular folder
-rw-r----- 1 root root
4649 Jan 16 18:05 pg_hba.conf
drwxr-xr-x 3 root root
4096 Jan 12 21:18 unnati
root@hj-glbtal8591:~#
How do I put (upload) file into another
UNIX server using SFTP?
root@11.55.225.55's
password:
Connected to
11.55.225.55.
sftp> put
pg_hba.conf
sftp> quit
Some SFTP commands:
sftp> help
(or) sftp> ? ---shows available commands in
SFTP
sftp > !ls ---to list files in local directory (your
machine)
sftp > ls ---to list files in remote
directory (remote machine)
sftp> mget *.xls
---Get multiple files on a local system
sftp> !pwd --- Local
working directory
sftp> pwd
----Remote working directory(print the current directory on the ftp server)
sftp> put
pg_hba.conf ---put pg_hba.conf file
in remote directory
sftp> mput
*.xls ----to put multiple files on
remote directory
sftp > cd path
----Change remote directory to 'path'
sftp> bye --- Quit sftp
sftp> exit ---- Quit sftp
sftp>
quit ---- Quit sftp
sftp> mkdir
persistent ---Create
remote directory
sftp> !mkdir
persistent --- Create local directory(in
your machine)
sftp> rmdir persistent ----remove remote directory
sftp> version -----shows FTP version
sftp> ! ---go back to local directory/ quit sftp
sftp> !cat
> persistent ---Execute 'command' in local shell/local
machine
sftp> rm path ---Delete
remote file
Uninstalling software:
$ apt-get purge <postgresql-server-dev-9.3>
Installing software:
$sudo apt-get
install <python3-minimal>
wget command examples:
The quick and
effective method to download software, music, video from internet is using wget
command.
$ wget http://prdownloads.sourceforge.net/sourceforge/nagios/nagios-3.2.1.tar.gz
$sudo
http_proxy='http://name:pwd@brproxy.company.co.in:8080' apt-get
install git
run .bashrc on your current terminal
session to source ~/.export file.
echo "source ~/.exports" >> ~/.bashrc ???????
Connecting and Working on remote host:
ssh (SSH client)
is a program for logging into a remote machine and for executing commands on a
remote machine.
root@hj-glbtal8591:~#
ssh -l root 10.51.226.43 ---connecting to remote host
root@hj-glbtal8592:~#
exit ---goes back to original host
Awk command examples:
$ awk '{print $2,$5;}' persistent
---prints 2 and 5 fields from persistent file
Part3
Vim command examples:
$vim +10 pg_hba.conf ---goes
to the 10 line of pg_hba.conf
$Cd - ---takes
back to previous working directory
$echo $SHELL ---Gives shell name
Converting all charters in a file to
upper case (dd command):
$dd if=persistent
of=persistent_new conv=ucase --if=
input file , of=output file, conv=convert, ucase=uppercase
$dd
if=persistent_new of=persistent_new1 conv=lcase
---creates new file persistent_new1
with lowercase chareacters
$file * ---gives all files names and their details in
the current directory
echo "hi krishna,
how are you?" ----prints
same
echo "hi
krishna,\n how are you?" ----- \n is
used for next line
echo "hi
krishna,\r how are you?" -----
\r
is used for removing, preceding it
echo "hi
krishna,\t how are you?"
------ \t is used for giving four spaces
echo "hi
krishna,\b how are you?"
-------\b is for back space
echo
"\033[1mhi krishna,how are you?\033[0m" ----\033[1m
is used for printing in bold
\033[0m
at the end is used for discontinuing boldness
echo "\033[7mhi
krishna,how are you? \033[0m"
----\033[7m is used for printing
background in black
Zip unzipping files:
$ gzip hari2 ---to zip a file
$ gunzip hari2 ----to unzip a file
$ TeradataStudioExpress64__linux_x86_64.16.00.01.00-1.tar.gz ----file to be unzipped and untarred
$ gunzip
TeradataStudioExpress64__linux_x86_64.16.00.01.00-1.tar.gz ---to unzip a file
$ tar -xf
TeradataStudioExpress64__linux_x86_64.16.00.01.00-1.tar ----to untar a tar file
$ tar -xzf
TeradataStudioExpress64__linux_x86_64.16.00.01.00-1.tar ----to unzip and untar a tar file
ZIP a folder:
$ tar zcvf
nameofcompressedfile.tar.gz /path/to/folder/compressthisfolder
--we can’t zip a directory in UNIX, hence
archive using tar as above.
Scripting:
Using commands in script:
$vi
using_command.sh ---step1
create a file
#using commands
in a script ----step2 writing script in vi
pwd
ls –la
$sh
using_command.sh ---step3
executing script
/root/Krishna -----output
total 136
drwxr-xr-x 2 root
root 4096 Jan 20 17:54 .
drwx------ 7 root
root 4096 Jan 20 17:54 ..
Script to read a name:
$vi read.sh
echo "enter
your name"
read your_name ---‘read ‘ is used for taking
input
echo "hi
$your_name how are you"
$sh read.sh
enter your name
krishna
hi krishna how
are you
Script to rename a file and open:
$vi
rename_file.sh
echo "enter
file_name"
read file_name ---Giving the required name (creates new file
file_name)
mv persistent
$file_name ---persistent file renamed to
file_name
cat $file_name
$sh
rename_file.sh
Script for reading two file names and
renaming file1 to file2:
$vi
rename_file1.sh
echo "enter
file name1"
read file_1 -----reads file1 which already exists
in server
echo "enter
file name2"
read file_2 -----reads file2, which is a new file
mv $file_1
$file_2 ----renames file1 to file2
cat $file_2 ----opens file2
Positional parameters:
$ set Krishna
from Kamalapuram
$ echo $1 ---gives 1st string
Krishna
$ echo $2 ---gives 2nd string
from
$ echo $3 ---gives 3rd string
Kamalapuram
Script for set Positional parameter:
$ vi posional_parameters.sh
set Krishna from
village1
echo $1
echo $2
echo $3
$ sh posional_parameters.sh
Krishna
from
Kamalapuram
Set can be used
in a script as well as command prompt.
When set is given
different sentence then, previous parameters are over written.
$ set hari from
village2
$ echo $* ---we
get all the strings
hari from village2
Note: Executable files are in Green color.
Assigning positional parameters from a
file:
$ cat > test
hi Krishna, how
are you?
$ set `cat test`
$ echo $*
hi Krishna, how
are you?
While loop Script:
$vi while_loop.sh
#script for while
loop
a=0
while [ $a -le 5
]
do
echo $a
a=`expr $a + 1`
done
$sh while_loop.sh
0
1
2
3
4
5
For loop Script:
$ vi for_loop.sh
#for loop to read
text and print it
for i in 1 2 3 4
do echo $i
done
$ sh for_loop.sh
1
2
3
4
Script to create a file and enter data
into it:
$ vi
file_creation.sh
#create a file
and populate it
cat > hk
echo "from
psl" >> hk
$ sh
file_creation.sh
Ctrl+d
Script using Break:
$ vi break.sh
#using break to
stop a process
a=0
while [ $a -lt 10
]
do
echo $a
if [ $a -eq 5 ]
then break
fi
a=`expr $a + 1`
done
$sh break.sh
0
1
2
3
4
5
Script for arithmetic operators:
$ vi
arithmetic_operators.sh
#arithmatic
operators
a=32 b=15
echo `expr $a +
$b`
echo `expr $a -
$b`
echo `expr $a \*
$b` ----we have to give \ before *
echo `expr $a /
$b`
echo `expr $a %
$b` ------gives remainder
$ sh
arithmetic_operators.sh
47
17
480
2
2
Note: expr works only with integer values.
Order of operation: Bracket, division,
multiplication, modular division, addition and subtraction (BODMAS)
Working with floating numbers:
$vi floating.sh
a=10.5
b=3.5
c=`echo $a + $b |
bc` ---bc is used for working with
floating numbers
d=`echo $a - $b |
bc`
echo $c $d
Script if user is ‘root’ then script is executed
$ vi unix1.sh
#if user is root
then script is executed
a=`whoami`
if [ $a = 'root'
]
then
echo
"authorised"
else
echo
"not authorised"
exit
fi
echo
"hello"
date
$ sh unix1.sh
authorised
hello
Tue Jan 31
18:19:49 IST 2017
If Script in korn shell:
$ vi test7.ksh --step1: open file in vi
#!/bin/ksh --step2: code in vi
a=10
b=10
c=10
if [ $a == $b ] && [ $b ==
$c ]
then
echo "a is equal to b and b =c "
else
echo "None of the condition met"
fi
$ ./test7.ksh --step3: execution of korn script
#!/bin/ksh
a=Pass
b=Pass
c=2
if [ $a == Pass ]
&& [ $b == Pass ] && [ $c=2 ]
then
echo "Pass "
else
echo "Fail"
fi
o/p:
cdts10hdbe01d:abwdusr:/home/abwdusr>
./test7.ksh
Pass
Script to check date is valid or not:
x=22/02/22222
if [[ $x ==
[0-3][0-9]/[0-1][0-9]/[0-9][0-9][0-9][0-9] ]]
then echo "valid"
else echo "invalid"
fi
cdts10hdbe01d:abwdusr:/home/abwdusr>
./test11.ksh
invalid
Script to check Column is numeric or not:
#!/bin/ksh
export a=`awk
-F',' '{print $3}' prod_test.csv | awk ' $1 ~ "^[0-9][0-9]*$"' |wc
-l`
export b=`awk
-F',' '{print $2}' prod_test.csv | awk ' $1 ~ "^[0-9][0-9]*$"' |wc
-l`
c=`expr $a + $b`
print $c
Child Vs Parent Process:
Any process can
be a parent and child process at the same time. The only exception is the init
process, which is always marked with PID (process ID) 1. Therefore, init is a
parent of all processes running on your Linux system.
$ ps -p 1
PID TTY TIME CMD
1 ? 00:00:02 init
Any process
created will normally have a parent process from which it was created and will
be considered as a child of this parent process. For example:
$ echo $$
27861
$ bash
$ echo $$
28034
$ ps --ppid 27861
PID TTY TIME CMD
28034 pts/3 00:00:00 bash
- Line 1:
print a PID for a current shell - 27861
- Line 2:
create a new child process from the process ID 27861
- Line 3:
print a PID for a current shell - 28034
- Line 4:
with use of the ps command
print the child process of PID 27861
When creating a
new child process an export command simply ensures that any exported variables
in the parent process are available in the child process.
To find out default login shell:
$ which bash
/bin/bash
(or)
$ who am i
chris pts/0 2011-11-26 07:19 (:0.0)
$ grep chris
/etc/passwd
cnegus:x:13597:13597:ravi Negus:/home/cnegus:/bin/bash
File last modified time:
$ date -r <file_name>
Find where particular command came from:
You can use the type command.
e.g.: $ type cat
cat is a tracked
alias for /bin/cat
To view your history list:
Use the history command
e.g.: $ history
0 -- --after
logging in it shows from 1st used command to last used command
Sequential commands/using multiple commands:
$ date ; uname ;
whoami
Wed Jul 26
10:56:51 EDT 2017
Linux
Sdtdusr
Part4
Mailing:
$ mail -s
"hi how r u" hk@in.company.com
Ctrl+d ---to
add mail id in CC
Ctrl+c
(or)
$ echo "Mail
body" | mail -s "Subject" hk@in.company.com --enter
echo "For
testing" | mailx -s "Testing" hk@in.company.com --mail and mailx works as same
Script to send mail:
vi test.ksh
#!/bin/ksh
MESSAGE="hi
How are u?"
SUBJECT="Greeting"
TOADDR="hk@in.company.com"
FROM="DONOTREPLY"
echo $MESSAGE |
mail -s "$SUBJECT" $TOADDR --
-f $FROM
./test.ksh
Script to send CSV file:
#!/bin/ksh
MESSAGE="hi How are u?"
SUBJECT="Greeting"
TOADDR="hk@in.company.com"
FROM="DONOTREPLY"
echo "$MESSGE" | mail -s
"$SUBJECT" -a
"/development/abc/data/ABC_PRDCT.csv" $TOADDR
-- -f $FROM
--any file can be
send like this
To find a file whose location is not known:
$ vi $(find /home
| grep xyzzy) ----doesn’t workin Kornshell
Export Usage:
$
m=hk1/hk2/hk3 ----assign m with the directory path hk1/hk2/hk3
$ export m ----exporting m
$ cd $m -----going to path hk1/hk2/hk3
Echo:
$ echo $$ ---returns process ID of the current shell
$ echo $(date) ---------prints date
Thu Jul 27
06:45:54 EDT 2017
Note:
Variables can contain the output of a command or command
sequence. You can accomplish this by preceding the command with a dollar sign
and open parenthesis, and following it with a closing parenthesis. For example,
MYDATE=$(date)
$ echo date -----here
date is treated as string
date
Calculation:
$ echo "I am
$[2012 - 1957] years old." ---works in Bash Shell
I am 55 years
old.
Echo:
$ hari=krishna
$ echo ${hari:-"no data"}
krishna
$ hari=
$ echo ${hari:-"no data"}
no data
Find a file using echo:
$ echo *txt
---------------------------------------------------------------
----------------------
$ echo "This
is \" a quote and this is \\ a backslash"
This is " a
quote and this is \ a backslash
So backslash
itself must be escaped to show that it is to be taken literally.
$ alias ls
alias ls='ls
--color=auto' ---The --color=auto option
causes different types of files and directories to be displayed in different colors.
Counting no: of
files in directory and assigning it to a variable:
$ num_files=$(ls -la
| wc -l )
$ echo $num_files
5
When
assigning variables, use only the variable name (for example, BALANCE). When
you reference variable,
meaning
you want the value of the variable, precede it with a dollar sign (as in
$CurBalance). The result of the
latter
is that you get the value of the variable, not the variable name itself.
$ echo
"count :: ${num_files}"
count :: 5
$
hk1=${num_files-""}
$ echo $hk1
5
$
hk2=${num_files-"hi"}
$ echo $hk2
5
$ THIS="Example"
$ THIS=${THIS:-"Not
Set"}
$ THAT=${THAT:-"Not
Set"}
$ echo $THIS
Example
$ echo $THAT
Not Set
Shell
Program1:
$ vi file4
read -p "Your
name? " name
if [[ $name = $USER
]]; then
echo "Hello, me."
else
echo "Hello, $name."
fi
$ sh file4
Your name? hk
Hello, hk.
---------------------------------------------------------------
-------------------------------------------------------------
Passing a Parameter in shell Script:
1)
Create a ksh file in the pathà
/development/abc/exe/
vi hari_practice1.ksh
. $1
echo "Hi Hari !" > ${DATA_FOLDER}/hari_practice1.txt
exit 0
2)
Create a parm file in the pathà /development/abc/parms/
Vi hari_practice1.parms
export DATA_FOLDER=/development/abc/data
Note: To run ksh and
parameter file.
/development/abc/exe/test_esp.ksh /development/abc/parms/esp_test.parms
3)
Now check the file in the path /development/abc/data
---------------------
-------------------------------------------------
----------------------------------------- ------------------
Usage of NOHUP:
-- nohup prevents the command from being
aborted if you log
out or exit the shell.
$nohup run_script.sh
> hk1.out & --& used for running the command in
background and note the process id
-----------------------
------------------------------------ --------------------------
back-ground Process:
$ ps l
<PID> --to check back-ground Process
$ps -f ---gives background running jobs
$kill -9
<process_id> ---to
kill background running process.
$cat
hari& ---add at the end of a command to
run the process in the back ground
-------------------------------
--------------------------------------------------
---------------------------------------------------
Command to change the shell:
$ chsh -s /bin/ksh
dos2unix:
$ dos2unix
/home/tptuusr/.profile --converts a
file from dos to UNIX compatible
How to check
whether dos2unix is performed on a file? :
$ cat -ve <file_name>
---you will see $ at the end
Script to create a file by reading input
from user:
$ vi script.sh
#!/bin/sh
echo "What is your name?"
read USER_NAME
echo "Hello $USER_NAME"
echo "I will create you a file
called ${USER_NAME}_file"
touch "${USER_NAME}_file"
For loop:
#!/bin/sh
for i in hello 1 * 2 goodbye
do
echo "Looping ... i is set to $i"
done
Output:
Looping ... i is set to hello
Looping ... i is set to 1
Looping ... i is set to (name of first file in current directory)
... etc ...
Looping ... i is set to (name of last file in current directory)
Looping ... i is set to 2
Looping ... i is set to goodbye
While Loop:
#!/bin/sh
while [ "$INPUT_STRING" != "bye" ]
do
echo "Please type something in (bye to quit)"
read INPUT_STRING
echo "You typed: $INPUT_STRING"
done
What
happens here, is that the echo and read statements will run indefinitely until
you type "bye" when prompted
Script to list all files in a directory:
#!/bin/sh
for i in *
do
echo
"$i"
done
While loop:
#!/bin/sh
echo "Please talk to me
..."
while : ###colon always
evaluates to true
do
read INPUT_STRING
case $INPUT_STRING in
hello)
echo "Hello yourself!"
;;
bye)
vi echo "See you again!"
break
;;
*)
echo "Sorry, I don't understand"
;;
esac
done
echo
echo "That's all folks!"
Usage of Typeset:
$ typeset -xu
h=ram
$ echo $h
RAM
Curl:
--curl is used for downloading a file from web
----------------------------------------------
-------------------
---------------------------------------
-----------------------------------------------
$ rm -rf --rm removes a file in directory, r –removes all files in a directory
recursively -- forcefully
Ping:
$ ping
8.8.8.8 ---ping lets you know other machine on the internet is live
---8.8.8.8 is Google’s public DNS SERVER
Bc:
$ bc ----it
is a calculator program, we can do calculations here , press CTRL+D after using
‘bc’
---------------------
--------------------------------------------------------------------
Searching Large files:
$ less <file
_name> --- we can search page at a time
--- press ESC q to exit or :q
--- /production to search production and
press n for next occurrence
Even in vi
/<word_name> works
-----------------------------------
-------------------------------------------------------------------------------------------------------
Note:
File names can
contain any character except / . If file
contains spaces or any special characters then put file name in ‘quotes’ or
precede each special character with \
-------------------------------------------------------------
--------------------------------------------------
View:
$ view <file_name>
ESCàG ---goes to last line in view
Getting total columns from a file:
export Field_count=`head -1
${FILE} | sed 's/[^,]//g' | wc -c`
Validate a date in unix:
To get Echo screen set below ones:
#!/bin/ksh
#set -vx
#shopt -s -o nounset
#umask 113
numeric check on columns
awk -F',' '{print $2}' test1.csv | awk ' $1 ~
"^[0-9][0-9]*$"' |wc -l ---gives
total columns with only numeric data
****************
***********
$ a=-10
$ b=${a#-}
$ echo $b
10
Give row numbers to a file in unix:
$ awk '{printf
"%d~%s\n", NR, $0}' test_dtl
Script to add row numbers in other folder than
current:
#!/bin/ksh
pwd echo "gives current path in
script"
cd /home/abwdusr/hk1/
echo "adding row number
starts for all files"
awk '{printf "%d~%s\n",
NR, $0}' dtl.csv > dtl_rowno.csv
awk '{printf "%d~%s\n",
NR, $0}' prod.csv > prod_rowno.csv
echo "adding row number
ends"
script to remove files in some folder:
#!/bin/ksh
cd /home/abwdusr/hk1 #Have to parameterize
rm dtl_rowno.csv prod_rowno.csv
unzipping thru script:
#!/bin/ksh
cd /home/abcdusr/hk1
gunzip dtl.csv
gunzip prod.csv
echo "unzipping ends"
unzips if any file is .gz format
Script to create a directory and create a file in
it:
#!/bin/ksh
echo "Setting up Env"
cd /home/abcdusr
echo "Current Directory
`pwd`"
if [ ! -d
"/home/abcdusr/hk2" ]
then
mkdir hk2
fi
echo "removing all the old
files"
rm -f /home/abwdusr/hk2/*.*
cd /home/abwdusr/hk2
echo "hi" > test1
echo "
Script Execution Completed @
`date`"
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