redirection in linux with examples
Case1)
You can use redirection command to creat new file and you can add text to that file
Enter this coomand
Cat > devops.txt press enter
After entering this command you will enter into new promt
And write conetnt you want to write
Here iam writing
devops 1
devops 2
devops 3
after writing evrything to save it press
cntrl+d
So now you will out of that promt
If you want to see content of that file you can use
cat devops.txt
you can see above data
case2)
already you have some data now if you enter same coomand cat > devops.txt
u will enter into prompt now add new content
devops 4
devops 5
devops 6 and press cntrl+d now cat the file
cat devops.txt
you can see only new data so earlier whatever content you have overwritten is overwritten by the new content
case3)
if you want to append new content into that file that means whatever you written in second time
that content will added to previous content from next line
for this we have to use this command
cat >> devops.txt
>> is appending symbol new content is added to previous content
So now iam adding new content
Linux 7
Linux 8
Linux 9 and press control+d
Now cat the file cat devops.txt
devops 4
devops 5
devops 6
Linux 7
Linux 8
Linux 9
You can see all the data
So if you want to append to the existing content of the file you have to use >>
Case 4)
If you want to add the content of two files and transfer it to new file
U can use this command
Cat first.txt second.txt > third.txt
So here the content of first.txt and second.txt file will added and transferred into new file third.txt
If the file(third.txt) doesn’t exist it will create new file and send it to third.txt
You can check output with cat third.txt
If you want to add more than two files
Cat first.txt second.txt third.txt …………..> final.txt
Case 5)
If you want append content of one file to another file
That means if you want to add content of first file to second file you can use this command
Cat first.txt >> second.txt