Shell scripts $? variable: In a shell script, we can check the return status immediately after running any command to determine if command is successful or not. like echo $? if return status is 0, it indicates success, and if the return status is non-zero, typically 1, means failure. /dev/null /dev/null is a special device file in Unix-like operating systems (including Linux) that discards all data written to it. It essentially acts as a black hole for data. When data is written to /dev/null, it simply disappears and does not consume any storage space. Here are some common use cases for /dev/null: Discarding Output: As mentioned earlier, redirecting output to /dev/null is a common way to discard unwanted output, such as diagnostic messages or verbose output, especially when running scripts or commands in the background where you don't need to see the output. command >/dev/null # Redirects stdout to /dev/null command 2>/dev/null # Redirects stderr to /dev/null command ...
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