參數： -a Display an entry for each file in a file hierarchy. -c Display a grand total. -d depth Display an entry for all files and directories depth directories deep. -H Symbolic links on the command line are followed, symbolic links in file hierarchies are not followed. -h "Human-readable" output. Use unit suffixes: Byte, Kilobyte, Megabyte, Gigabyte, Terabyte and Petabyte. -I mask Ignore files and directories matching the specified mask. -g Display block counts in 1073741824-byte (1-Gbyte) blocks. -k Display block counts in 1024-byte (1-Kbyte) blocks. -L Symbolic links on the command line and in file hierarchies are followed. -m Display block counts in 1048576-byte (1-Mbyte) blocks. -P No symbolic links are followed. This is the default. -r Generate messages about directories that cannot be read, files that cannot be opened, and so on. This is the default case. This option exists solely for conformance with X/Open Portability Guide Issue 4 (``XPG4''). -s Display an entry for each specified file. (Equivalent to -d 0) -x File system mount points are not traversed.