CHMOD(1) CHMOD(1) chmod - chmod [OPTION]... MODE[,MODE]... FILE... chmod [OPTION]... OCTAL-MODE FILE... chmod [OPTION]... --reference=RFILE FILE... GNU chmod. chmod file mode . [ugoa...][[-+=][perms...]...] perms rwxXst ugo. . ugoa : (u) (g) (o) (a). (a) umask . + - = . rwxXst : (r) (w) ( ) (x) / (X) (s) (t). ugo: (u) (g) (o). (0-7) 4 2 1. . (4) (2) (1). : (4) (2) (1) . chmod chmod . chmod . chmod . OPTIONS. SETUID SETGID chmod . MODE RFILE. chmod . . chmod . u+s g-s. 00755 -6000 =755. . /tmp. . FILE MODE. --reference FILE RFILE. -c, --changes -f, --silent, --quiet -v, --verbose --dereference -h, --no-dereference --no-preserve-root '/' () --preserve-root '/' --reference=RFILE RFILE MODE. RFILE . -R, --recursive -R . . -H . -H -L -P --help --version MODE '[ugoa]*([-+=]([rwxXst]*|[ugo]))+|[-+=][0-7]+'. David MacKenzie Jim Meyering. : bug-coreutils@gnu.org GNU coreutils : : (C) 2026 (Free Software Foundation, Inc.). GPLv3+: GNU GPL 3 . . : . . chmod(2) : info '(coreutils) chmod invocation' 3 . . : . GNU coreutils 9.11 2026 CHMOD(1)