(Note that &>>file appends to a file while &> would redirect and overwrite a previously existing file.) To combine stdout and stderr you would redirect the latter to the former using 1>&2. This redirects stdout (file descriptor 1) to stderr (file descriptor 2), e.g.: $ { echo “stdout”; echo “stderr” 1>&2; } | grep -v … Read more
It would be neater to capture the error file thus: ERROR=$(</tmp/Error) The shell recognizes this and doesn’t have to run ‘cat‘ to get the data. The bigger question is hard. I don’t think there’s an easy way to do it. You’d have to build the entire pipeline into the sub-shell, eventually sending its final standard … Read more
Standard input – this is the file handle that your process reads to get information from you. Standard output – your process writes conventional output to this file handle. Standard error – your process writes diagnostic output to this file handle. That’s about as dumbed-down as I can make it 🙂 Of course, that’s mostly … Read more
If you want to log to the same file: command1 >> log_file 2>&1 If you want different files: command1 >> log_file 2>> err_file
Take a look here. It should be: yourcommand &> filename It redirects both standard output and standard error to file filename.
First redirect stderr to stdout — the pipe; then redirect stdout to /dev/null (without changing where stderr is going): command 2>&1 >/dev/null | grep ‘something’ For the details of I/O redirection in all its variety, see the chapter on Redirections in the Bash reference manual. Note that the sequence of I/O redirections is interpreted left-to-right, … Read more
I found this to be the only one short, flexible, portable and readable: # This line only if you still care about Python2 from __future__ import print_function import sys def eprint(*args, **kwargs): print(*args, file=sys.stderr, **kwargs) The optional function eprint saves some repetition. It can be used in the same way as the standard print function: … Read more
cmd >>file.txt 2>&1 Bash executes the redirects from left to right as follows: >>file.txt: Open file.txt in append mode and redirect stdout there. 2>&1: Redirect stderr to “where stdout is currently going”. In this case, that is a file opened in append mode. In other words, the &1 reuses the file descriptor which stdout currently … Read more