SHELL命令之chmod

root@bt:~/test# chmod --helpUsage: chmod [OPTION]... MODE[,MODE]... FILE...  or:  chmod [OPTION]... OCTAL-MODE FILE...  or:  chmod [OPTION]... --reference=RFILE FILE...Change the mode of each FILE to MODE.  -c, --changes           like verbose but report only when a change is made      --no-preserve-root  do not treat `/' specially (the default)      --preserve-root     fail to operate recursively on `/'  -f, --silent, --quiet   suppress most error messages  -v, --verbose           output a diagnostic for every file processed      --reference=RFILE   use RFILE's mode instead of MODE values  -R, --recursive         change files and directories recursively      --help     display this help and exit      --version  output version information and exitEach MODE is of the form `[ugoa]*([-+=]([rwxXst]*|[ugo]))+'.