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Question
In linux, if you run the command "ls exiting_file.txt non-existing_file.txt", and the output on the prompt is:
ls: cannot access non-existing_file.txt: No such file or directory
-rw-rw-r-- 1 kevin kevin 6 Oct 17 16:03 existing_file.txt

Reissue the ls command above such that you capture all of the above output (i.e. the error message and the output line) to a file called "output.txt"?

Answer

ls existing_file.txt non-existing_file.txt > output.txt 2>&1
^^ note: the 2>&1, means redirect stderr (2) to stdout(1) and since things are executed from right to left this must be declared before the "> output.txt" part
^^ note: the first >, is same as 1> which means redirect stdout (i.e. 1) to output.txt

^^^ shorthand is just: ls existing_file.txt non-existing_file.txt &> output.txt


Question
In linux, if you run the command "ls exiting_file.txt non-existing_file.txt", and the output on the prompt is:
ls: cannot access non-existing_file.txt: No such file or directory
-rw-rw-r-- 1 kevin kevin 6 Oct 17 16:03 existing_file.txt

Reissue the ls command above such that you capture all of the above output (i.e. the error message and the output line) to a file called "output.txt"?

Answer
?

Question
In linux, if you run the command "ls exiting_file.txt non-existing_file.txt", and the output on the prompt is:
ls: cannot access non-existing_file.txt: No such file or directory
-rw-rw-r-- 1 kevin kevin 6 Oct 17 16:03 existing_file.txt

Reissue the ls command above such that you capture all of the above output (i.e. the error message and the output line) to a file called "output.txt"?

Answer

ls existing_file.txt non-existing_file.txt > output.txt 2>&1
^^ note: the 2>&1, means redirect stderr (2) to stdout(1) and since things are executed from right to left this must be declared before the "> output.txt" part
^^ note: the first >, is same as 1> which means redirect stdout (i.e. 1) to output.txt

^^^ shorthand is just: ls existing_file.txt non-existing_file.txt &> output.txt

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8. Streams and sed -- The Stream Editor
ipe x into pipe y. Redirection is specified from right to left on the command-line. Hence, the above command means to mix stderr into stdout and then to redirect stdout to the file A . Finally, <span>ls existing_file non-existing_file 2>A 1>&2 cat A We notice that this has the same effect, except that here we are doing the reverse: redirecting stdout into stderr and then redirecting stderr into a file A . To see what happens

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