Adding output of one command to the bottom of another file?

romeo0307 · 05-07-2012, 07:54 PM

Hi guys. It's me again

Here is what I have this time:

paste -d: file1 file 2

This needs to be combined with another command to make it 1 command using either | or > or something like that.

And it needs to go to the bottom of file3

Please help!

suicidaleggroll · 05-07-2012, 07:56 PM

You need to be more specific. What is the other command? What are you trying to put into file3? The more specific you are, the faster and more accurate the advice will be.

In general, ">>" will append the output of a command to the end of a file, IE: "ls >> outfile"

sycamorex · 05-07-2012, 07:59 PM

Yes, you are on the right track. Apart from the piper character '|', make sure you know the difference between > and >>

romeo0307 · 05-07-2012, 08:00 PM

Quote:

Originally Posted by suicidaleggroll

You need to be more specific. What is the other command? What are you trying to put into file3? The more specific you are, the faster and more accurate the advice will be.

In general, ">>" will append the output of a command to the end of a file, IE: "ls >> outfile"

Duh! Thanks, that was so simple.

David the H. · 05-08-2012, 02:09 PM

Yes, the usual, recommended way is just to do something like this:

Code:

command1 > file
command2 >> file

It's also possible to use command grouping or subshells to direct the output of multiple commands at once.

Code:

{ command1 ; command2 ; } > outfile

( command1 ; command2 ) > outfile

Finally, you can use cat and process substitution to combine multiple inputs together. This works well when you want to combine output form both files and commands.

Code:

cat infile1 <(command1) infile2 <(command2) >outfile