When running the command sed -e "s/a/b/" /tmp/file /tmp/file While /tmp/file contains data, why is /tmp/file empty afterwards?

Question

When running the command sed -e "s/a/b/" /tmp/file >/tmp/file While /tmp/file contains data, why is /tmp/file empty afterwards?

Martin White · Accepted Answer

When the shell establishes the redirection it overwrites the target file before the redirected command starts and opens itfor reading.

Martin White · Answer

The file order is incorrect. The destination file must be mentioned before the command to ensure redirection.

Martin White · Answer

The command sed did not match anything in that file therefore the output is empty.

Martin White · Answer

Redirection for shell commands do not work using the > character. It only works using the | character instead.

List of questions