sed command in unix

$ vi sample.txt
$ cat sample.txt
one two three
this is example for sed substitution
$ cat sample.txt|sed 's/t/T/'
one Two three
This is example for sed substitution
$ cat sample.txt|sed 's/t/T/g'
one Two Three
This is example for sed subsTiTuTion

$ sed 's/t/T/g' sample.txt
one Two Three
This is example for sed subsTiTuTion
$ cat sample.txt
one two three
this is example for sed substitution
$ sed -i 's/t/T/g' sample.txt
$ cat sample.txt
one Two Three
This is example for sed subsTiTuTion
$
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[oracle]$ cat sample.txt
one two three
10 aug 1991
5 may 2020
sed command is used to replace string or characters
[oracle]$ sed 's/[0-9]/*/g' sample.txt
one two three
** aug ****
* may ****
sed command is used to replace string or characters
[oracle]$ sed 's/[0-9][0-9]/*/g' sample.txt
one two three
* aug **
5 may **
sed command is used to replace string or characters
[oracle]$ sed 's/[0-9]/(&)/g' sample.txt
one two three
(1)(0) aug (1)(9)(9)(1)
(5) may (2)(0)(2)(0)
sed command is used to replace string or characters
[oracle]$ sed 's/[a-z]/(&)/g' sample.txt
(o)(n)(e) (t)(w)(o) (t)(h)(r)(e)(e)
10 (a)(u)(g) 1991
5 (m)(a)(y) 2020
(s)(e)(d) (c)(o)(m)(m)(a)(n)(d) (i)(s) (u)(s)(e)(d) (t)(o) (r)(e)(p)(l)(a)(c)(e) (s)(t)(r)(i)(n)(g) (o)(r) (c)(h)(a)(r)(a)(c)(t)(e)(r)(s)
[oracle]$ sed -i  's/t/T/g' sample.txt
[oracle]$ cat sample.txt
one Two Three
10 aug 1991
5 may 2020
sed command is used To replace sTring or characTers
[oracle]$ sed 's/[a-z]/*/g' sample.txt
*** T** T****
10 *** 1991
5 *** 2020
*** ******* ** **** T* ******* *T**** ** ******T***
[oracle]$ sed 's/[A-Z]/*/g' sample.txt
one *wo *hree
10 aug 1991
5 may 2020
sed command is used *o replace s*ring or charac*ers
[oracle]$ sed 's/[A-Za-z]/*/g' sample.txt
*** *** *****
10 *** 1991
5 *** 2020
*** ******* ** **** ** ******* ****** ** **********
[oracle]$ sed 's/[a-Z]/*/g' sample.txt
*** *** *****
10 *** 1991
5 *** 2020
*** ******* ** **** ** ******* ****** ** **********
[oracle]$ sed 's/[0-Z]/*/g' sample.txt
*** *** *****
** *** ****
* *** ****
*** ******* ** **** ** ******* ****** ** **********
You have mail in /var/spool/mail/ougbs
[oracle]$ sed 's/[0-5]/*/g' sample.txt
one Two Three
** aug *99*
* may ****
sed command is used To replace sTring or characTers
[oracle]$ sed 's/[d-m]/*/g' sample.txt
on* Two T*r**
10 au* 1991
5 *ay 2020
s** co**an* *s us** To r*p*ac* sTr*n* or c*aracT*rs
[oracle]$

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