BSD syscall#551
svc · unix #551
freadlink
Reads the target of a symbolic link referenced by an open file descriptor (macOS extension).
Prototype
int freadlink(int fd, user_addr_t buf, user_size_t bufsize);Returns: int
Arguments
| Name | Type | Dir | Description |
|---|---|---|---|
| fd | int | - | |
| buf | user_addr_t | - | |
| bufsize | user_size_t | - |
Version history
| XNU tag | macOS | # |
|---|---|---|
| xnu-8792.41.9 | macOS 13.0 Ventura | 551 |
| xnu-10002.1.13 | macOS 14.0 Sonoma | 551 |
| xnu-11215.1.10 | macOS 15.0 Sequoia | 551 |
| xnu-11417.101.15 | macOS 15.4 Sequoia | 551 |
| xnu-12377.1.9 | macOS 26.0 Tahoe | 551 |
| xnu-10002.41.9 | — | 551 |
| xnu-10002.61.3 | — | 551 |
| xnu-10002.81.5 | — | 551 |
| xnu-10063.101.15 | — | 551 |
| xnu-10063.121.3 | — | 551 |
| xnu-10063.141.1 | — | 551 |
| xnu-11215.41.3 | — | 551 |
| xnu-11215.61.5 | — | 551 |
| xnu-11215.81.4 | — | 551 |
| xnu-11417.121.6 | — | 551 |
| xnu-11417.140.69 | — | 551 |
| xnu-12377.101.15 | — | 551 |
| xnu-12377.41.6 | — | 551 |
| xnu-12377.61.12 | — | 551 |
| xnu-12377.81.4 | — | 551 |
| xnu-8020.101.4 | — | 551 |
| xnu-8020.121.3 | — | 551 |
| xnu-8020.140.41 | — | 551 |
| xnu-8792.61.2 | — | 551 |
| xnu-8792.81.2 | — | 551 |
| xnu-8796.101.5 | — | 551 |
| xnu-8796.121.2 | — | 551 |
| xnu-8796.141.3 | — | 551 |
Notes
Useful when the link was opened with O_SYMLINK and the caller already holds a fd. Avoids re-resolving the path and is safe against namespace changes between open and read.
Detection
syscall::freadlink:entry in DTrace.
Related APIs
readlinkreadlinkatopensymlink