unlink

Implemented in Antinomie 0.7.0 · Syscall list

Synopsis

long unlink(const char *pathname);

Number (x86-64)	87
ABI	common
Kernel entry point	sys_unlink

This is the raw kernel prototype from the pinned Linux 6.12.94 schema, not the libc wrapper.

Description

Removes a name from the filesystem; the file is freed when no name or open descriptor remains.

Arguments

Name	Type	Meaning
pathname (arg0)	const char *	Path, as a NUL-terminated string in user memory.

Return value

On success: 0.

In an Antinomie trace the Return column and the ret filter field show the raw kernel return value. On failure that is the negative errno, for example -2 for ENOENT, not the -1 plus errno that the libc wrapper gives. syscall.errno holds the positive errno and syscall.success is false.

Common errors

Raw return	Name	Meaning
-13	EACCES	Permission denied.
-2	ENOENT	A path component or the named object does not exist.
-1	EPERM	The operation is not permitted for this process.

Man page

unlink(2) on man7.org

Captured by Antinomie

Coverage mark: Implemented. Every pointer argument has a capture rule in the pinned kernel patch and none of them records a “no decoder”, “address only” or “not observed” gap on any code path. Individual values can still be incomplete on a particular call; see the capture statuses.

Every call is recorded as an Entry record (the six argument words and the pointees copied at entry) and an Exit record (the return value and the pointees copied at exit).

Arguments

Argument	When	How	Recorded field key	Condition
pathname (arg0)	Entry	the pointer itself, as a raw word	args.0, args.raw[0]
↳ pointee	Entry	NUL-terminated string, up to 4,096 bytes (PATH_MAX)	arg0.path	always

Derived and lifecycle records

• A lifecycle.file_id record (kind Unlink) identifies the inode whose name was removed, with the links it has left. Before a regular file is removed, the guest queues its SHA-256 and publishes it as a lifecycle.file_hash record (kind Delete), or the reason there is none. Written by a base built for Antinomie 0.7.0 or later.

Filter fields

• Result: ret, syscall.errno, syscall.success, syscall.duration_ns.
• Argument words: args.pathname (arg0); args.0 to args.5 by position.
• Captured strings: the args.<name> field of a path argument, and args.path, give the captured text instead of the pointer.

See Syscall Trace filter for the full syntax.

For what the capture statuses mean, see Capture statuses. For what is never recorded, see Known gaps.