So, in your ubuntu docker container, you want to use bash redirection if you want to write the regular script screen logs or out messages to one file and errors to another at the same time.
There are two types of output redirection in bash to handle this scenario,
stdout or 1The STDOUT is the standard output of a shell command or script. We can use “>” or “1>” to redirect them.
stderr or 2The STDERR, which is any error or warning messages from a script or command. We can use “2>” to redirect them.
Examples of stdout and stderr redirections
Consider the below scenario, where we are running the ls -l towards two files, one exists and the other does not.
We will get the standard output and standard error as follows:
To send the outputs to two different files, we are going to use redirects
The syntax for redirecting stderr and stdout to separate files.
ls -l code.txt try.txt > out.log 2> error.log
Here, the first redirect > instructs the shell to send standard out (1) to the file out.log. You can also use the syntax as 1> out.log
second redirect 2> requests the shell to send error(2) messages to error.log – 2> error.log
Output redirection demo:
Let us check the output
Redirecting to /dev/null, or silencing the output.
If you want to suppress or silence any one of the output, you can redirect it to /dev/null – which is a system file
ls 1> /dev/null
In this case, the standard output will not be visible or written to the file, instead redirected to /dev/null
Similarly, to ignore all errors by redirecting them to /dev/null, the Syntax is:
ls 2> /dev/null
Please feel free to ask if you have questions.