Documentation
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Overview ¶
Package procfd provides Linux open-file-descriptor enumeration for the lsof builtin.
Only Linux is supported; macOS and Windows return ErrNotSupported (the same shape as builtins/internal/meminfo, used by the Linux-only free builtin).
This package is in builtins/internal/ and is therefore exempt from the per-command builtinAllowedSymbols check applied to files under builtins/. Its own stdlib/unix symbol usage is still tracked in analysis/symbols_internal.go's internalAllowedSymbols and internalPerPackageSymbols["procfd"].
Privacy: this package never reads a process's argv/cmdline or environ. The Command field is the comm name only (matching builtins/internal/ procinfo), not the full argv[0] or any argument.
Index ¶
Constants ¶
const MaxFDsPerProcess = 10_000
MaxFDsPerProcess caps the number of file descriptors read per process to bound work against processes with pathologically large (or spoofed) open-file counts.
const MaxProcesses = 10_000
MaxProcesses caps the number of processes scanned, matching procinfo.MaxProcesses.
const MaxTotalOpenFiles = 100_000
MaxTotalOpenFiles caps the aggregate number of OpenFile entries returned by a single List call, across every scanned process. MaxProcesses and MaxFDsPerProcess each bound one dimension, but their product (up to 100M entries) is still an unbounded-memory risk for a plain, selector-less scan; this caps the sum directly.
Variables ¶
var ErrNotSupported = errors.New("not supported on this platform")
ErrNotSupported is returned by List on platforms without a backend.
Functions ¶
This section is empty.
Types ¶
type OpenFile ¶
type OpenFile struct {
PID int
Command string // comm name only; never argv
UID string // real UID, as a numeric string
FD string // "cwd", "rtd", "txt", or a numeric descriptor
Type string // REG, DIR, CHR, BLK, FIFO, sock, a_inode, unknown
Device string // "major,minor" of the underlying device, "" if unknown
Size string // file size in bytes as a decimal string, "" if unknown
Node string // inode number as a decimal string, "" if unknown
Name string // resolved target; a filesystem path when IsPath is true
// IsPath reports whether Name is a filesystem path that must be
// checked against the caller's AllowedPaths configuration before
// being shown. Non-path targets (sockets, pipes, anonymous inodes)
// are never gated.
IsPath bool
// Deleted reports whether the kernel marked this descriptor's target
// as unlinked (the " (deleted)" suffix on the /proc/<pid>/fd symlink
// target). Name has the suffix stripped; callers re-append a marker
// as needed.
Deleted bool
}
OpenFile describes a single open file descriptor (or descriptor-like entry: cwd, root, exe) held by a process.
func List ¶
func List(ctx context.Context, procPath string, pids []int, filter ProcessFilter) ([]OpenFile, error)
List returns open file descriptors for the given PIDs. A nil or empty pids selects every process visible under procPath (bounded by MaxProcesses). Missing or inaccessible PIDs are silently skipped, since processes can exit between listing and reading. filter, if non-nil, restricts scanning to processes it accepts.
type ProcessFilter ¶
ProcessFilter reports whether a process, identified by its PID, comm name, and real UID, should be scanned for open files. It is evaluated once per process, before that process's fd directory is scanned, so a non-matching process's file descriptors never consume any of the caller's MaxTotalOpenFiles budget. A nil filter matches every process.
Source Files