Module chmod

Expand description

Recursive permission/ownership changes (chmod/chgrp/chown) over a fileset.

The public entry point is chmod; it mirrors crate::rm() but transforms metadata in place (from a per-type rule) instead of removing entries.

Structs§

GetentResolver: Decides which getent binary name resolution spawns, hardened against PATH attacks when privileged. Built once from the CLI via GetentResolver::from_cli.
ModeProgram: Per-type mode rules. Symlinks are never included (mode bits aren’t settable on Linux symlinks).
OwnerProgram: Which user/group id (if any) to apply to each entry type. None leaves that type unchanged for this operation.
Settings: Configuration for a recursive chmod/chgrp/chown run.
Summary
SymbolicClause: One [ugoa][+-=][rwxXst] clause. who/perms are bitmasks (see WHO_* / PERM_*).

IdKind: Whether a DSL id token refers to a user or group.
ModeOp: The operator in a symbolic mode clause: add, remove, or set permissions.
ModeSpec: A parsed chmod mode expression: either a symbolic program (applied relative to the current mode) or an absolute octal value (12-bit).

apply_mode: Apply a mode spec to a current 12-bit mode, returning the new 12-bit mode. is_dir drives the conditional X permission.
chmod: Public entry point. Applies metadata changes to path and, recursively, its contents. Mirrors crate::rm::rm for the root-filter check.
is_privileged: Whether this process runs with elevated privilege: effective-root, or a setuid mismatch (real ≠ effective uid). rchm is not installed setuid, but the mismatch check is cheap defense-in-depth. The check keys on uid, not Linux capabilities, so a CAP_CHOWN deployment without effective-root is treated as unprivileged (there the PATH is the operator’s own, not a third party’s).
parse_mode_dsl: Parse a --mode DSL string. A bare token is the default for files+dirs; f:/d: sections override per type. l: is rejected (symlink mode bits are not settable on Linux).
parse_owner_dsl: Parse a --group/--owner DSL string. A bare token is the default for all types; f:/d:/l: sections override per type. getent locates the getent binary used to resolve any non-numeric, NSS-only names (see GetentResolver).