CODEWITHSUNDEEP
linuxunixterminal
Jorge
Jorge

Reputation: 66

Reverse /dev/null

I am writing a program and needed to momentarily silence the output. I went online and found the solution was the following:

./program > /dev/null

I now need to see the output, but have not found a way to do so. After looking for it online, I now understand that what I'm basically doing is sending the output to a 'black hole', and I believe what I need to do is send the output of the program back to the Standard Output.

I've tried:

./program >1
./program >stdout
./program /dev/null>1
./program /dev/null>stdout

but still cannot get it to work. Does anybody know a possible solution?

Upvotes: 1

Views: 559

Answers (2)

StephenG - Help Ukraine
StephenG - Help Ukraine

Reputation: 965

You have stated twice that your program without redirection on the command line produces no output. So the problem is your program, not the redirection.

Also note that :

./program /dev/null>1
./program /dev/null>stdout

Both of these, which you tried, pass "/dev/null" as an argument to your application and apply redirection to that.

If you want to output to both stdout and a file using redirection you need a tee command.

You would use something like :

./program | tee mylogfiletxt

The '|' is a pipe between the output of program and the input of the tee application. tee will send a copy of its input to stdout and the file you name.

Upvotes: 0

DilithiumMatrix
DilithiumMatrix

Reputation: 18627

You can't get back the previous output. But just running the program normally will produce output to stdout...

./program

The > ('redirection' operator), redirects the output of the program while it is running to the target file (or stream). You don't need to 'undo' or 'reverse' this in subsequent runs. Wikipedia has a great overview.

Upvotes: 6

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