File System Comparisons

There are many significant differences between the two major file systems on Mac OS X: HFS+ and UFS. In many cases, these differences have some bearing on programs developed for Mac OS X. The following list summarizes the major differences between these file systems (many of these statements apply to HFS as well as HFS+):

In addition, the interfaces historically associated with each file system sometimes have different behaviors. For example, a program using BSD (or BSD-derived) interfaces can delete a file that is open; on the other hand, a Carbon program can delete only a file that is closed.

Table 1 provides a comparative summary of features in the UFS and HFS+ file systems.

Table 1  Feature comparison

Feature

HFS+

UFS

Case sensitive

No

Yes

Supports multiple file forks

Yes

No

Path separator character

“:”

“/”

Supports modification dates

Yes

Yes

Supports creation dates

Yes

No

Supports sparse files

No

Yes

Supports zero-filling of files

Yes

No

Supports aliases

Yes

No

Supports symbolic links

Yes

Yes

Supports ACLs

Yes

No