<&n redirect standard input from file descriptor n >&n redirect standard output to file descriptor n n<file redirect file descriptor n from file n>file redirect file descriptor n to file n>>file redirect file descriptor n to file. Create file if non-existent, else overwrite. n>| file redirect file descriptor n to file. Create file even if noclobber is enabled. n<&m redirect file descriptor n input from file descriptor m n>&m redirect file descriptor n output to file descriptor m n<>file open file for reading and writing as file descriptor n n<<word redirect to file descriptor n until word is read n<<-word redirect to file descriptor n until word is read; ignore leading tabs n<&- close file descriptor n for standard input n>&- close file descriptor n for standard output print &un args redirect arguments to file descriptor n. If n is greater than 2, it must first be opened with exec. If n is not specified, the default file descriptor argument is 1 (standard output). read &un args read input line from file descriptor n. If n is greater than 2, it must first be opened with exec. If n is not specified, the default file descriptor argument is 0 (standard input).