What does 2 mean in Linux?

File descriptor 2 represents standard error. (other special file descriptors include 0 for standard input and 1 for standard output). 2> /dev/null means to redirect standard error to /dev/null . /dev/null is a special device that discards everything that is written to it.

What is exit status in Unix?

Every Linux or Unix command executed by the shell script or user has an exit status. Exit status is an integer number. 0 exit status means the command was successful without any errors. A non-zero (1-255 values) exit status means command was a failure.

What does 2 mean in shell script?

2 refers to the second file descriptor of the process, i.e. stderr . > means redirection. &1 means the target of the redirection should be the same location as the first file descriptor, i.e. stdout . So > /dev/null 2>&1 first redirects stdout to /dev/null and then redirects stderr there as well.

What does an exit status or return code of 2 mean for make?

2. There was an error in the makefile.

What is the exit status of a command?

The exit status of an executed command is the value returned by the waitpid system call or equivalent function. Exit statuses fall between 0 and 255, though, as explained below, the shell may use values above 125 specially. Exit statuses from shell builtins and compound commands are also limited to this range.

What is an exit status in Linux?

What is the purpose of 2 >& 1?

File descriptors are used to identify stdout (1) and stderr (2); command > output is just a shortcut for command 1> output ; You can use &[FILE_DESCRIPTOR] to reference a file descriptor value; Using 2>&1 will redirect stderr to whatever value is set to stdout (and 1>&2 will do the opposite).

What is 2 and1 Dev Null?

command >> /dev/null 2>&1 /dev/null is a standard file that discards all you write to it, but reports that the write operation succeeded. 1 is standard output and 2 is standard error. 2>&1 redirects standard error to standard output.