STDBUF(1) STDBUF(1) stdbuf - , . stdbuf ... , . . -i, --input= -o, --output= -e, --error= --help --version ,,L" . . ,,0" . Otherwise MODE is a number which may be followed by one of the following: KB 1000, K 1024, MB 1000*1000, M 1024*1024, and so on for G,T,P,E,Z,Y,R,Q. Binary prefixes can be used, too: KiB=K, MiB=M, and so on. In this case the corresponding stream will be fully buffered with the buffer size set to MODE bytes. : (tee(1) ) stdbuf-. ( dd(1) cat(1) .) /, stdbuf-. Exit status: 125 if the stdbuf command itself fails 126 if COMMAND is found but cannot be invoked 127 if COMMAND cannot be found - the exit status of COMMAND otherwise tail -f access.log | stdbuf -oL cut -d ' ' -f1 | uniq This will immediately display unique entries from access.log On GLIBC platforms, specifying a buffer size, i.e., using fully buffered mode will result in undefined operation. . coreutils: Copyright (C) 2023 Free Software Foundation, Inc. 3+: 3 . : . , . ,,info '(coreutils) stdbuf invocation'" ; 3 . . , - TODO <>. coreutils 9.4 2024 STDBUF(1)