Shell script - 4
To go to Session 1 click here
To go to Session 2 click here
To go to Session 3 click here
To go to UNIX basic commands click here
Online sample UNIX TERMINAL click here
A function is very use full to break your functionality or program in to little/small programs which will easy to handle. And easy to debug the issue when occurs.
To go to Session 1 click here
To go to Session 2 click here
To go to Session 3 click here
To go to UNIX basic commands click here
Online sample UNIX TERMINAL click here
Functions :
A function is very use full to break your functionality or program in to little/small programs which will easy to handle. And easy to debug the issue when occurs.
In shell script
function can be written with the help of following syntax:
Function_name()
{
statements
}
Example 13:
#!/bin/sh
funtionone()
{
echo "I am in funtion one"
funtiontwo hi how r u
ret=$?
echo "funtion two returned
$ret"
}
funtiontwo()
{
echo "I am in funtion two,funtion
one called me with $* as arguments i"
return 1
}
funtionone
Out put:
Testhome/l685360#
./test
I am in
funtion one
I am in
funtion two,funtion one called me with hi how r u as arguments i
funtion two
returned 1
Testhome/l685360#
In the above example 13 there are two functions functionone and
functionstwo we call the functionone by the statement funtionone this function
in turn calls the second function with arguments “hi how r u” the function two
in turn retun back with value 1. I didn’t explain the echo because its all self
explanatory.
The sed
The stream Editor, It is powerful utility of
unix, generally used to edit / modify a text files.
The S(Substitution)
Example 14:
Testhome/l685360# vi
sed1
Hi baskar,
i well come u to the festival ,
Testhome/l685360# sed
s/baskar/mohan/ <sed1 >sed2
Testhome/l685360# cat
sed1
Hi baskar,
i well come u to the festival ,
Testhome/l685360# cat
sed2
Hi mohan,
i well come u to the festival ,
Testhome/l685360#
In the above example the substitution is used the name baskar in sed1
file is changed to mohan and saved in
another file sed2 the symbol <> refers to redirection look for unix
redirection for explanation.
Things to understand
1.
s command
2.
delimiters
/ / (you can use anything as delimiter as you wish for example (Example 15:
echo
jaya | sed s:jaya:jai: ) here we have used : as delimiter)
3.
(baskar)
the word to be found
4.
(mohan)
the word to be changed finally the command would be
5.
sed
s/baskar/mohan/ <inputfile >outputfile
this can also be done
for a string for example
Example 16:
Testhome/l685360# echo
jayachandran | sed s/jaya/jai/
jaichandran
Testhome/l685360#
The &
Example 17:
Testhome/l685360#echo
“1365 jai 19b” | sed ‘s/[0-9]*/(&)/’
(1365) jai 19b
Testhome/l685360#
In the above example
the sequence or a specific pattern is put between some spl. Char. Like () and
so on.
The P
Example 18( without
-n):
MTS-REG ;titrs105:(l685360)/home/l685360# sed p<sed1
Hi baskar,
Hi baskar,
i well come u to the festival ,
i well come u to the festival ,
Example 19( with -n)
MTS-REG ;titrs105:(l685360)/home/l685360# sed -n
p<sed1
Hi baskar,
i well come u to the festival ,
MTS-REG ;titrs105:(l685360)/home/l685360#
The option p will
print the input, if –n is not given the p option alone will make duplicate of
each line in the input.
Thanks all...
Don't forget to put your feed back as comments which encourages me to do this and you can also post your questions or solve/give answers for others questions, Thanks in advance friends.....
Thanks all...
Don't forget to put your feed back as comments which encourages me to do this and you can also post your questions or solve/give answers for others questions, Thanks in advance friends.....