Port builtins/path to Rust

CMakeLists.txt

@@ -104,7 +104,7 @@ set(FISH_BUILTIN_SRCS
     src/builtins/disown.cpp
     src/builtins/eval.cpp src/builtins/fg.cpp
     src/builtins/functions.cpp src/builtins/history.cpp
-    src/builtins/jobs.cpp src/builtins/path.cpp
+    src/builtins/jobs.cpp
     src/builtins/read.cpp src/builtins/set.cpp
     src/builtins/source.cpp
     src/builtins/ulimit.cpp

fish-rust/src/builtins/mod.rs

@@ -13,6 +13,7 @@ pub mod emit;
 pub mod exit;
 pub mod function;
 pub mod math;
+pub mod path;
 pub mod printf;
 pub mod pwd;
 pub mod random;

fish-rust/src/builtins/shared.rs

@@ -1,4 +1,5 @@
 use crate::builtins::{printf, wait};
+use crate::common::str2wcstring;
 use crate::ffi::separation_type_t;
 use crate::ffi::{self, parser_t, wcstring_list_ffi_t, Repin, RustBuiltin};
 use crate::wchar::{wstr, WString, L};
@@ -6,9 +7,14 @@ use crate::wchar_ffi::{c_str, empty_wstring, ToCppWString, WCharFromFFI};
 use crate::wgetopt::{wgetopter_t, wopt, woption, woption_argument_t};
 use cxx::{type_id, ExternType};
 use libc::c_int;
-use std::os::fd::RawFd;
+use std::borrow::Cow;
+use std::fs::File;
+use std::io::{BufRead, BufReader, Read};
+use std::os::fd::{FromRawFd, RawFd};
 use std::pin::Pin;
 
+pub type BuiltinCmd = fn(&mut parser_t, &mut io_streams_t, &mut [&wstr]) -> Option<c_int>;
+
 #[cxx::bridge]
 mod builtins_ffi {
     extern "C++" {
@@ -225,6 +231,7 @@ pub fn run_builtin(
         RustBuiltin::Emit => super::emit::emit(parser, streams, args),
         RustBuiltin::Exit => super::exit::exit(parser, streams, args),
         RustBuiltin::Math => super::math::math(parser, streams, args),
+        RustBuiltin::Path => super::path::path(parser, streams, args),
         RustBuiltin::Pwd => super::pwd::pwd(parser, streams, args),
         RustBuiltin::Random => super::random::random(parser, streams, args),
         RustBuiltin::Realpath => super::realpath::realpath(parser, streams, args),
@@ -336,3 +343,143 @@ impl HelpOnlyCmdOpts {
         })
     }
 }
+
+#[derive(PartialEq)]
+pub enum SplitBehavior {
+    Newline,
+    /// The default behavior of the -z or --null-in switch,
+    /// Automatically start splitting on NULL if one appears in the first PATH_MAX bytes.
+    /// Otherwise on newline
+    InferNull,
+    Null,
+    Never,
+}
+
+/// A helper type for extracting arguments from either argv or stdin.
+pub struct Arguments<'args, 'iter> {
+    /// The list of arguments passed to the string builtin.
+    args: &'iter [&'args wstr],
+    /// If using argv, index of the next argument to return.
+    argidx: &'iter mut usize,
+    split_behavior: SplitBehavior,
+    /// Buffer to store what we read with the BufReader
+    /// Is only here to avoid allocating every time
+    buffer: Vec<u8>,
+    /// If not using argv, we read with a buffer
+    reader: Option<BufReader<File>>,
+}
+
+impl Drop for Arguments<'_, '_> {
+    fn drop(&mut self) {
+        if let Some(r) = self.reader.take() {
+            // we should not close stdin
+            std::mem::forget(r.into_inner());
+        }
+    }
+}
+
+impl<'args, 'iter> Arguments<'args, 'iter> {
+    pub fn new(
+        args: &'iter [&'args wstr],
+        argidx: &'iter mut usize,
+        streams: &mut io_streams_t,
+        chunk_size: usize,
+    ) -> Self {
+        let reader = streams.stdin_is_directly_redirected().then(|| {
+            let stdin_fd = streams
+                .stdin_fd()
+                .filter(|&fd| fd >= 0)
+                .expect("should have a valid fd");
+            // safety: this should be a valid fd, and already open
+            let fd = unsafe { File::from_raw_fd(stdin_fd) };
+            BufReader::with_capacity(chunk_size, fd)
+        });
+
+        Arguments {
+            args,
+            argidx,
+            split_behavior: SplitBehavior::Newline,
+            buffer: Vec::new(),
+            reader,
+        }
+    }
+
+    pub fn with_split_behavior(mut self, split_behavior: SplitBehavior) -> Self {
+        self.split_behavior = split_behavior;
+        self
+    }
+
+    fn get_arg_stdin(&mut self) -> Option<(Cow<'args, wstr>, bool)> {
+        use SplitBehavior::*;
+        let reader = self.reader.as_mut().unwrap();
+
+        if self.split_behavior == InferNull {
+            // we must determine if the first `PATH_MAX` bytes contains a null.
+            // we intentionally do not consume the buffer here
+            // the contents will be returned again later
+            let b = reader.fill_buf().ok()?;
+            if b.contains(&b'\0') {
+                self.split_behavior = Null;
+            } else {
+                self.split_behavior = Newline;
+            }
+        }
+
+        // NOTE: C++ wrongly commented that read_blocked retries for EAGAIN
+        let num_bytes: usize = match self.split_behavior {
+            Newline => reader.read_until(b'\n', &mut self.buffer),
+            Null => reader.read_until(b'\0', &mut self.buffer),
+            Never => reader.read_to_end(&mut self.buffer),
+            _ => unreachable!(),
+        }
+        .ok()?;
+
+        // to match behaviour of earlier versions
+        if num_bytes == 0 {
+            return None;
+        }
+
+        // assert!(num_bytes == self.buffer.len());
+        let (end, want_newline) = match (&self.split_behavior, self.buffer.last().unwrap()) {
+            // remove the newline — consumers do not expect it
+            (Newline, b'\n') => (num_bytes - 1, true),
+            // we are missing a trailing newline!
+            (Newline, _) => (num_bytes, false),
+            // consumers do not expect to deal with the null
+            // "want_newline" is not currently relevant for Null
+            (Null, b'\0') => (num_bytes - 1, false),
+            // we are missing a null!
+            (Null, _) => (num_bytes, false),
+            (Never, _) => (num_bytes, false),
+            _ => unreachable!(),
+        };
+
+        let parsed = str2wcstring(&self.buffer[..end]);
+
+        let retval = Some((Cow::Owned(parsed), want_newline));
+        self.buffer.clear();
+        retval
+    }
+}
+
+impl<'args> Iterator for Arguments<'args, '_> {
+    // second is want_newline
+    // If not set, we have consumed all of stdin and its last line is missing a newline character.
+    // This is an edge case -- we expect text input, which is conventionally terminated by a
+    // newline character. But if it isn't, we use this to avoid creating one out of thin air,
+    // to not corrupt input data.
+    type Item = (Cow<'args, wstr>, bool);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.reader.is_some() {
+            return self.get_arg_stdin();
+        }
+
+        if *self.argidx >= self.args.len() {
+            return None;
+        }
+        let retval = (Cow::Borrowed(self.args[*self.argidx]), true);
+        *self.argidx += 1;
+        return Some(retval);
+    }
+}

fish-rust/src/builtins/string.rs

@@ -1,18 +1,12 @@
-use std::borrow::Cow;
-use std::fs::File;
-use std::io::{BufRead, BufReader, Read};
-use std::os::fd::FromRawFd;
-
-use crate::common::str2wcstring;
 use crate::wcstringutil::fish_wcwidth_visible;
 // Forward some imports to make subcmd implementations easier
 use crate::{
     builtins::shared::{
         builtin_missing_argument, builtin_print_error_trailer, builtin_print_help, io_streams_t,
-        BUILTIN_ERR_ARG_COUNT0, BUILTIN_ERR_ARG_COUNT1, BUILTIN_ERR_COMBO2,
-        BUILTIN_ERR_INVALID_SUBCMD, BUILTIN_ERR_MISSING_SUBCMD, BUILTIN_ERR_NOT_NUMBER,
-        BUILTIN_ERR_TOO_MANY_ARGUMENTS, BUILTIN_ERR_UNKNOWN, STATUS_CMD_ERROR, STATUS_CMD_OK,
-        STATUS_INVALID_ARGS,
+        Arguments, SplitBehavior, BUILTIN_ERR_ARG_COUNT0, BUILTIN_ERR_ARG_COUNT1,
+        BUILTIN_ERR_COMBO2, BUILTIN_ERR_INVALID_SUBCMD, BUILTIN_ERR_MISSING_SUBCMD,
+        BUILTIN_ERR_NOT_NUMBER, BUILTIN_ERR_TOO_MANY_ARGUMENTS, BUILTIN_ERR_UNKNOWN,
+        STATUS_CMD_ERROR, STATUS_CMD_OK, STATUS_INVALID_ARGS,
     },
     ffi::{parser_t, separation_type_t},
     wchar::{wstr, WString, L},
@@ -302,126 +296,16 @@ fn escape_code_length(code: &wstr) -> Option<usize> {
     }
 }
 
-/// A helper type for extracting arguments from either argv or stdin.
-struct Arguments<'args, 'iter> {
-    /// The list of arguments passed to the string builtin.
+/// Empirically determined.
+/// This is probably down to some pipe buffer or some such,
+/// but too small means we need to call `read(2)` and str2wcstring a lot.
+const STRING_CHUNK_SIZE: usize = 1024;
+fn arguments<'iter, 'args>(
     args: &'iter [&'args wstr],
-    /// If using argv, index of the next argument to return.
     argidx: &'iter mut usize,
-    /// If set, when reading from a stream, split on newlines.
-    split_on_newline: bool,
-    /// Buffer to store what we read with the BufReader
-    /// Is only here to avoid allocating every time
-    buffer: Vec<u8>,
-    /// If not using argv, we read with a buffer
-    reader: Option<BufReader<File>>,
-}
-
-impl Drop for Arguments<'_, '_> {
-    fn drop(&mut self) {
-        if let Some(r) = self.reader.take() {
-            // we should not close stdin
-            std::mem::forget(r.into_inner());
-        }
-    }
-}
-
-impl<'args, 'iter> Arguments<'args, 'iter> {
-    /// Empirically determined.
-    /// This is probably down to some pipe buffer or some such,
-    /// but too small means we need to call `read(2)` and str2wcstring a lot.
-    const STRING_CHUNK_SIZE: usize = 1024;
-
-    fn new(
-        args: &'iter [&'args wstr],
-        argidx: &'iter mut usize,
-        streams: &mut io_streams_t,
-    ) -> Self {
-        let reader = streams.stdin_is_directly_redirected().then(|| {
-            let stdin_fd = streams
-                .stdin_fd()
-                .filter(|&fd| fd >= 0)
-                .expect("should have a valid fd");
-            // safety: this should be a valid fd, and already open
-            let fd = unsafe { File::from_raw_fd(stdin_fd) };
-            BufReader::with_capacity(Self::STRING_CHUNK_SIZE, fd)
-        });
-
-        Arguments {
-            args,
-            argidx,
-            split_on_newline: true,
-            buffer: Vec::new(),
-            reader,
-        }
-    }
-
-    fn without_splitting_on_newline(
-        args: &'iter [&'args wstr],
-        argidx: &'iter mut usize,
-        streams: &mut io_streams_t,
-    ) -> Self {
-        let mut args = Self::new(args, argidx, streams);
-        args.split_on_newline = false;
-        args
-    }
-
-    fn get_arg_stdin(&mut self) -> Option<(Cow<'args, wstr>, bool)> {
-        let reader = self.reader.as_mut().unwrap();
-
-        // NOTE: C++ wrongly commented that read_blocked retries for EAGAIN
-        let num_bytes = match self.split_on_newline {
-            true => reader.read_until(b'\n', &mut self.buffer),
-            false => reader.read_to_end(&mut self.buffer),
-        }
-        .ok()?;
-
-        // to match behaviour of earlier versions
-        if num_bytes == 0 {
-            return None;
-        }
-
-        let mut parsed = str2wcstring(&self.buffer);
-
-        // If not set, we have consumed all of stdin and its last line is missing a newline character.
-        // This is an edge case -- we expect text input, which is conventionally terminated by a
-        // newline character. But if it isn't, we use this to avoid creating one out of thin air,
-        // to not corrupt input data.
-        let want_newline;
-        if self.split_on_newline {
-            if parsed.char_at(parsed.len() - 1) == '\n' {
-                // consumers do not expect to deal with the newline
-                parsed.pop();
-                want_newline = true;
-            } else {
-                // we are missing a trailing newline
-                want_newline = false;
-            }
-        } else {
-            want_newline = false;
-        }
-
-        let retval = Some((Cow::Owned(parsed), want_newline));
-        self.buffer.clear();
-        retval
-    }
-}
-
-impl<'args> Iterator for Arguments<'args, '_> {
-    // second is want_newline
-    type Item = (Cow<'args, wstr>, bool);
-
-    fn next(&mut self) -> Option<Self::Item> {
-        if self.reader.is_some() {
-            return self.get_arg_stdin();
-        }
-
-        if *self.argidx >= self.args.len() {
-            return None;
-        }
-        *self.argidx += 1;
-        return Some((Cow::Borrowed(self.args[*self.argidx - 1]), true));
-    }
+    streams: &mut io_streams_t,
+) -> Arguments<'args, 'iter> {
+    Arguments::new(args, argidx, streams, STRING_CHUNK_SIZE)
 }
 
 /// The string builtin, for manipulating strings.

fish-rust/src/builtins/string/collect.rs

@@ -31,7 +31,9 @@ impl StringSubCommand<'_> for Collect {
     ) -> Option<libc::c_int> {
         let mut appended = 0usize;
 
-        for (arg, want_newline) in Arguments::without_splitting_on_newline(args, optind, streams) {
+        for (arg, want_newline) in
+            arguments(args, optind, streams).with_split_behavior(SplitBehavior::Never)
+        {
             let arg = if !self.no_trim_newlines {
                 let trim_len = arg.len() - arg.chars().rev().take_while(|&c| c == '\n').count();
                 &arg[..trim_len]

fish-rust/src/builtins/string/escape.rs

@@ -45,7 +45,7 @@ impl StringSubCommand<'_> for Escape {
         };
 
         let mut escaped_any = false;
-        for (arg, want_newline) in Arguments::new(args, optind, streams) {
+        for (arg, want_newline) in arguments(args, optind, streams) {
             let mut escaped = escape_string(&arg, style);
 
             if want_newline {

fish-rust/src/builtins/string/join.rs

@@ -45,9 +45,9 @@ impl<'args> StringSubCommand<'args> for Join<'args> {
         }
 
         let Some(arg) = args.get(*optind).copied() else {
-           string_error!(streams, BUILTIN_ERR_ARG_COUNT0, args[0]);
-           return STATUS_INVALID_ARGS;
-       };
+            string_error!(streams, BUILTIN_ERR_ARG_COUNT0, args[0]);
+            return STATUS_INVALID_ARGS;
+        };
         *optind += 1;
         self.sep = arg;
 
@@ -64,7 +64,7 @@ impl<'args> StringSubCommand<'args> for Join<'args> {
         let sep = &self.sep;
         let mut nargs = 0usize;
         let mut print_trailing_newline = true;
-        for (arg, want_newline) in Arguments::new(args, optind, streams) {
+        for (arg, want_newline) in arguments(args, optind, streams) {
             if !self.quiet {
                 if self.no_empty && arg.is_empty() {
                     continue;

fish-rust/src/builtins/string/length.rs

@@ -33,7 +33,7 @@ impl StringSubCommand<'_> for Length {
     ) -> Option<libc::c_int> {
         let mut nnonempty = 0usize;
 
-        for (arg, _) in Arguments::new(args, optind, streams) {
+        for (arg, _) in arguments(args, optind, streams) {
             if self.visible {
                 // Visible length only makes sense line-wise.
                 for line in split_string(&arg, '\n') {

fish-rust/src/builtins/string/match.rs

@@ -110,7 +110,7 @@ impl<'args> StringSubCommand<'args> for Match<'args> {
             }
         };
 
-        for (arg, _) in Arguments::new(args, optind, streams) {
+        for (arg, _) in arguments(args, optind, streams) {
             if let Err(e) = matcher.report_matches(arg.as_ref(), streams) {
                 FLOG!(error, "pcre2_match unexpected error:", e.error_message())
             }

fish-rust/src/builtins/string/pad.rs

@@ -74,7 +74,7 @@ impl StringSubCommand<'_> for Pad {
         let mut inputs: Vec<(Cow<'args, wstr>, usize)> = Vec::new();
         let mut print_trailing_newline = true;
 
-        for (arg, want_newline) in Arguments::new(args, optind, streams) {
+        for (arg, want_newline) in arguments(args, optind, streams) {
             let width = width_without_escapes(&arg, 0);
             max_width = max_width.max(width);
             inputs.push((arg, width));

fish-rust/src/builtins/string/repeat.rs

@@ -55,7 +55,7 @@ impl StringSubCommand<'_> for Repeat {
         let mut first = true;
         let mut print_trailing_newline = true;
 
-        for (w, want_newline) in Arguments::new(args, optind, streams) {
+        for (w, want_newline) in arguments(args, optind, streams) {
             print_trailing_newline = want_newline;
             if w.is_empty() {
                 continue;

fish-rust/src/builtins/string/replace.rs

@@ -79,7 +79,7 @@ impl<'args> StringSubCommand<'args> for Replace<'args> {
 
         let mut replace_count = 0;
 
-        for (arg, want_newline) in Arguments::new(args, optind, streams) {
+        for (arg, want_newline) in arguments(args, optind, streams) {
             let (replaced, result) = match replacer.replace(arg) {
                 Ok(x) => x,
                 Err(e) => {

fish-rust/src/builtins/string/shorten.rs

@@ -72,7 +72,7 @@ impl<'args> StringSubCommand<'args> for Shorten<'args> {
         let mut min_width = usize::MAX;
         let mut inputs = Vec::new();
 
-        let iter = Arguments::new(args, optind, streams);
+        let iter = arguments(args, optind, streams);
 
         if self.max == Some(0) {
             // Special case: Max of 0 means no shortening.

fish-rust/src/builtins/string/split.rs

@@ -181,10 +181,10 @@ impl<'args> StringSubCommand<'args> for Split<'args> {
         let mut split_count = 0usize;
         let mut arg_count = 0usize;
 
-        let argiter = match self.is_split0 {
-            false => Arguments::new(args, optind, streams),
-            true => Arguments::without_splitting_on_newline(args, optind, streams),
-        };
+        let argiter = arguments(args, optind, streams).with_split_behavior(match self.is_split0 {
+            false => SplitBehavior::Newline,
+            true => SplitBehavior::Never,
+        });
         for (arg, _) in argiter {
             let splits: Vec<Cow<'args, wstr>> = match (self.split_from, arg) {
                 (Direction::Right, arg) => {

fish-rust/src/builtins/string/sub.rs

@@ -65,7 +65,7 @@ impl StringSubCommand<'_> for Sub {
         }
 
         let mut nsub = 0;
-        for (s, want_newline) in Arguments::new(args, optind, streams) {
+        for (s, want_newline) in arguments(args, optind, streams) {
             let start: usize = match self.start.map(i64::from).unwrap_or_default() {
                 n @ 1.. => n as usize - 1,
                 0 => 0,

fish-rust/src/builtins/string/transform.rs

@@ -25,7 +25,7 @@ impl StringSubCommand<'_> for Transform {
     ) -> Option<libc::c_int> {
         let mut n_transformed = 0usize;
 
-        for (arg, want_newline) in Arguments::new(args, optind, streams) {
+        for (arg, want_newline) in arguments(args, optind, streams) {
             let transformed = (self.func)(&arg);
             if transformed != arg {
                 n_transformed += 1;

fish-rust/src/builtins/string/trim.rs

@@ -72,7 +72,7 @@ impl<'args> StringSubCommand<'args> for Trim<'args> {
                 .count()
         };
 
-        for (arg, want_newline) in Arguments::new(args, optind, streams) {
+        for (arg, want_newline) in arguments(args, optind, streams) {
             let trim_start = self.left.then(|| to_trim_start(&arg)).unwrap_or(0);
             // collision is only an issue if the whole string is getting trimmed
             let trim_end = (self.right && trim_start != arg.len())

fish-rust/src/builtins/string/unescape.rs

@@ -38,7 +38,7 @@ impl StringSubCommand<'_> for Unescape {
         args: &[&wstr],
     ) -> Option<libc::c_int> {
         let mut nesc = 0;
-        for (arg, want_newline) in Arguments::new(args, optind, streams) {
+        for (arg, want_newline) in arguments(args, optind, streams) {
             if let Some(res) = unescape_string(&arg, self.style) {
                 streams.out.append(res);
                 if want_newline {

fish-rust/src/wutil/mod.rs

@@ -511,13 +511,13 @@ pub fn fish_wcswidth(s: &wstr) -> libc::c_int {
 /// problem). Therefore we include richer information.
 #[derive(Clone, Eq, Hash, Ord, PartialEq, PartialOrd)]
 pub struct FileId {
-    device: libc::dev_t,
-    inode: libc::ino_t,
-    size: u64,
-    change_seconds: libc::time_t,
-    change_nanoseconds: i64,
-    mod_seconds: libc::time_t,
-    mod_nanoseconds: i64,
+    pub device: libc::dev_t,
+    pub inode: libc::ino_t,
+    pub size: u64,
+    pub change_seconds: libc::time_t,
+    pub change_nanoseconds: i64,
+    pub mod_seconds: libc::time_t,
+    pub mod_nanoseconds: i64,
 }
 
 impl FileId {

src/builtin.cpp

@@ -38,7 +38,6 @@
 #include "builtins/functions.h"
 #include "builtins/history.h"
 #include "builtins/jobs.h"
-#include "builtins/path.h"
 #include "builtins/read.h"
 #include "builtins/set.h"
 #include "builtins/shared.rs.h"
@@ -381,7 +380,7 @@ static constexpr builtin_data_t builtin_datas[] = {
     {L"math", &implemented_in_rust, N_(L"Evaluate math expressions")},
     {L"not", &builtin_generic, N_(L"Negate exit status of job")},
     {L"or", &builtin_generic, N_(L"Execute command if previous command failed")},
-    {L"path", &builtin_path, N_(L"Handle paths")},
+    {L"path", &implemented_in_rust, N_(L"Handle paths")},
     {L"printf", &implemented_in_rust, N_(L"Prints formatted text")},
     {L"pwd", &implemented_in_rust, N_(L"Print the working directory")},
     {L"random", &implemented_in_rust, N_(L"Generate random number")},
@@ -580,6 +579,9 @@ static maybe_t<RustBuiltin> try_get_rust_builtin(const wcstring &cmd) {
     if (cmd == L"wait") {
         return RustBuiltin::Wait;
     }
+    if (cmd == L"path") {
+        return RustBuiltin::Path;
+    }
     if (cmd == L"printf") {
         return RustBuiltin::Printf;
     }

src/builtin.h

@@ -124,6 +124,7 @@ enum class RustBuiltin : int32_t {
     Emit,
     Exit,
     Math,
+    Path,
     Printf,
     Pwd,
     Random,

src/builtins/path.cpp

@@ -1,952 +0,0 @@
-// Implementation of the path builtin.
-#include "config.h"  // IWYU pragma: keep
-
-#include "path.h"
-
-#include <stdint.h>
-#include <sys/stat.h>
-#include <sys/types.h>
-#include <unistd.h>
-
-#include <algorithm>
-#include <climits>
-#include <cstdarg>
-#include <ctime>
-#include <cwchar>
-#include <map>
-#include <string>
-#include <unordered_map>
-#include <utility>
-
-#include "../builtin.h"
-#include "../common.h"
-#include "../env.h"
-#include "../fallback.h"  // IWYU pragma: keep
-#include "../io.h"
-#include "../maybe.h"
-#include "../parser.h"
-#include "../path.h"
-#include "../util.h"
-#include "../wcstringutil.h"
-#include "../wgetopt.h"
-#include "../wutil.h"  // IWYU pragma: keep
-
-// How many bytes we read() at once.
-// We use PATH_MAX here so we always get at least one path,
-// and so we can automatically detect NULL-separated input.
-#define PATH_CHUNK_SIZE PATH_MAX
-
-static void path_error(io_streams_t &streams, const wchar_t *fmt, ...) {
-    streams.err.append(L"path ");
-    std::va_list va;
-    va_start(va, fmt);
-    streams.err.append_formatv(fmt, va);
-    va_end(va);
-}
-
-static void path_unknown_option(parser_t &parser, io_streams_t &streams, const wchar_t *subcmd,
-                                const wchar_t *opt) {
-    path_error(streams, BUILTIN_ERR_UNKNOWN, subcmd, opt);
-    builtin_print_error_trailer(parser, streams.err, L"path");
-}
-
-// We read from stdin if we are the second or later process in a pipeline.
-static bool path_args_from_stdin(const io_streams_t &streams) {
-    return streams.stdin_is_directly_redirected;
-}
-
-static const wchar_t *path_get_arg_argv(int *argidx, const wchar_t *const *argv) {
-    return argv && argv[*argidx] ? argv[(*argidx)++] : nullptr;
-}
-
-// A helper type for extracting arguments from either argv or stdin.
-namespace {
-class arg_iterator_t {
-    // The list of arguments passed to this builtin.
-    const wchar_t *const *argv_;
-    // If using argv, index of the next argument to return.
-    int argidx_;
-    // If not using argv, a string to store bytes that have been read but not yet returned.
-    std::string buffer_;
-    // Whether we have found a char to split on yet, when reading from stdin.
-    // If explicitly passed, we will always split on NULL,
-    // if not we will split on NULL if the first PATH_MAX chunk includes one,
-    // or '\n' otherwise.
-    bool have_split_;
-    // The char we have decided to split on when reading from stdin.
-    char split_{'\0'};
-    // Backing storage for the next() string.
-    wcstring storage_;
-    const io_streams_t &streams_;
-
-    /// Reads the next argument from stdin, returning true if an argument was produced and false if
-    /// not. On true, the string is stored in storage_.
-    bool get_arg_stdin() {
-        assert(path_args_from_stdin(streams_) && "should not be reading from stdin");
-        assert(streams_.stdin_fd >= 0 && "should have a valid fd");
-        // Read in chunks from fd until buffer has a line (or the end if split_ is unset).
-        size_t pos;
-        while (!have_split_ || (pos = buffer_.find(split_)) == std::string::npos) {
-            char buf[PATH_CHUNK_SIZE];
-            long n = read_blocked(streams_.stdin_fd, buf, PATH_CHUNK_SIZE);
-            if (n == 0) {
-                // If we still have buffer contents, flush them,
-                // in case there was no trailing sep.
-                if (buffer_.empty()) return false;
-                storage_ = str2wcstring(buffer_);
-                buffer_.clear();
-                return true;
-            }
-            if (n == -1) {
-                // Some error happened. We can't do anything about it,
-                // so ignore it.
-                // (read_blocked already retries for EAGAIN and EINTR)
-                storage_ = str2wcstring(buffer_);
-                buffer_.clear();
-                return false;
-            }
-            buffer_.append(buf, n);
-            if (!have_split_) {
-                if (buffer_.find('\0') != std::string::npos) {
-                    split_ = '\0';
-                } else {
-                    split_ = '\n';
-                }
-                have_split_ = true;
-            }
-        }
-
-        // Split the buffer on the sep and return the first part.
-        storage_ = str2wcstring(buffer_, pos);
-        buffer_.erase(0, pos + 1);
-        return true;
-    }
-
-   public:
-    arg_iterator_t(const wchar_t *const *argv, int argidx, const io_streams_t &streams,
-                   bool split_null)
-        : argv_(argv), argidx_(argidx), have_split_(split_null), streams_(streams) {}
-
-    const wcstring *nextstr() {
-        if (path_args_from_stdin(streams_)) {
-            return get_arg_stdin() ? &storage_ : nullptr;
-        }
-        if (auto arg = path_get_arg_argv(&argidx_, argv_)) {
-            storage_ = arg;
-            return &storage_;
-        } else {
-            return nullptr;
-        }
-    }
-};
-}  // namespace
-
-enum {
-    TYPE_BLOCK = 1 << 0,  /// A block device
-    TYPE_DIR = 1 << 1,    /// A directory
-    TYPE_FILE = 1 << 2,   /// A regular file
-    TYPE_LINK = 1 << 3,   /// A link
-    TYPE_CHAR = 1 << 4,   /// A character device
-    TYPE_FIFO = 1 << 5,   /// A fifo
-    TYPE_SOCK = 1 << 6,   /// A socket
-};
-typedef uint32_t path_type_flags_t;
-
-enum {
-    PERM_READ = 1 << 0,
-    PERM_WRITE = 1 << 1,
-    PERM_EXEC = 1 << 2,
-    PERM_SUID = 1 << 3,
-    PERM_SGID = 1 << 4,
-    PERM_USER = 1 << 5,
-    PERM_GROUP = 1 << 6,
-};
-typedef uint32_t path_perm_flags_t;
-
-// This is used by the subcommands to communicate with the option parser which flags are
-// valid and get the result of parsing the command for flags.
-struct options_t {  //!OCLINT(too many fields)
-    bool perm_valid = false;
-    bool type_valid = false;
-    bool invert_valid = false;
-    bool relative_valid = false;
-    bool reverse_valid = false;
-    bool key_valid = false;
-    bool unique_valid = false;
-    bool unique = false;
-    bool have_key = false;
-    const wchar_t *key = nullptr;
-
-    bool null_in = false;
-    bool null_out = false;
-    bool quiet = false;
-
-    bool have_type = false;
-    path_type_flags_t type = 0;
-
-    bool have_perm = false;
-    // Whether we need to check a special permission like suid.
-    bool have_special_perm = false;
-    path_perm_flags_t perm = 0;
-
-    bool invert = false;
-    bool relative = false;
-    bool reverse = false;
-
-    const wchar_t *arg1 = nullptr;
-};
-
-static void path_out(io_streams_t &streams, const options_t &opts, const wcstring &str) {
-    if (!opts.quiet) {
-        if (!opts.null_out) {
-            streams.out.append_with_separation(str, separation_type_t::explicitly);
-        } else {
-            // Note the char - if this was a string instead we'd add
-            // a string of length 0, i.e. nothing
-            streams.out.append(str + L'\0');
-        }
-    }
-}
-
-static int handle_flag_q(const wchar_t **argv, parser_t &parser, io_streams_t &streams,
-                         const wgetopter_t &w, options_t *opts) {
-    UNUSED(argv);
-    UNUSED(parser);
-    UNUSED(streams);
-    UNUSED(w);
-    opts->quiet = true;
-    return STATUS_CMD_OK;
-}
-
-static int handle_flag_z(const wchar_t **argv, parser_t &parser, io_streams_t &streams,
-                         const wgetopter_t &w, options_t *opts) {
-    UNUSED(argv);
-    UNUSED(parser);
-    UNUSED(streams);
-    UNUSED(w);
-    opts->null_in = true;
-    return STATUS_CMD_OK;
-}
-
-static int handle_flag_Z(const wchar_t **argv, parser_t &parser, io_streams_t &streams,
-                         const wgetopter_t &w, options_t *opts) {
-    UNUSED(argv);
-    UNUSED(parser);
-    UNUSED(streams);
-    UNUSED(w);
-    opts->null_out = true;
-    return STATUS_CMD_OK;
-}
-
-static int handle_flag_t(const wchar_t **argv, parser_t &parser, io_streams_t &streams,
-                         const wgetopter_t &w, options_t *opts) {
-    if (opts->type_valid) {
-        if (!opts->have_type) opts->type = 0;
-        opts->have_type = true;
-        std::vector<wcstring> types = split_string_tok(w.woptarg, L",");
-        for (const auto &t : types) {
-            if (t == L"file") {
-                opts->type |= TYPE_FILE;
-            } else if (t == L"dir") {
-                opts->type |= TYPE_DIR;
-            } else if (t == L"block") {
-                opts->type |= TYPE_BLOCK;
-            } else if (t == L"char") {
-                opts->type |= TYPE_CHAR;
-            } else if (t == L"fifo") {
-                opts->type |= TYPE_FIFO;
-            } else if (t == L"socket") {
-                opts->type |= TYPE_SOCK;
-            } else if (t == L"link") {
-                opts->type |= TYPE_LINK;
-            } else {
-                path_error(streams, _(L"%ls: Invalid type '%ls'\n"), L"path", t.c_str());
-                return STATUS_INVALID_ARGS;
-            }
-        }
-        return STATUS_CMD_OK;
-    }
-    path_unknown_option(parser, streams, argv[0], argv[w.woptind - 1]);
-    return STATUS_INVALID_ARGS;
-}
-
-static int handle_flag_p(const wchar_t **argv, parser_t &parser, io_streams_t &streams,
-                         const wgetopter_t &w, options_t *opts) {
-    if (opts->perm_valid) {
-        if (!opts->have_perm) opts->perm = 0;
-        opts->have_perm = true;
-        std::vector<wcstring> perms = split_string_tok(w.woptarg, L",");
-        for (const auto &p : perms) {
-            if (p == L"read") {
-                opts->perm |= PERM_READ;
-            } else if (p == L"write") {
-                opts->perm |= PERM_WRITE;
-            } else if (p == L"exec") {
-                opts->perm |= PERM_EXEC;
-            } else if (p == L"suid") {
-                opts->perm |= PERM_SUID;
-                opts->have_special_perm = true;
-            } else if (p == L"sgid") {
-                opts->perm |= PERM_SGID;
-                opts->have_special_perm = true;
-            } else if (p == L"user") {
-                opts->perm |= PERM_USER;
-                opts->have_special_perm = true;
-            } else if (p == L"group") {
-                opts->perm |= PERM_GROUP;
-                opts->have_special_perm = true;
-            } else {
-                path_error(streams, _(L"%ls: Invalid permission '%ls'\n"), L"path", p.c_str());
-                return STATUS_INVALID_ARGS;
-            }
-        }
-        return STATUS_CMD_OK;
-    }
-    path_unknown_option(parser, streams, argv[0], argv[w.woptind - 1]);
-    return STATUS_INVALID_ARGS;
-}
-
-static int handle_flag_perms(const wchar_t **argv, parser_t &parser, io_streams_t &streams,
-                             const wgetopter_t &w, options_t *opts, path_perm_flags_t perm) {
-    if (opts->perm_valid) {
-        if (!opts->have_perm) opts->perm = 0;
-        opts->have_perm = true;
-        opts->perm |= perm;
-        return STATUS_CMD_OK;
-    }
-    path_unknown_option(parser, streams, argv[0], argv[w.woptind - 1]);
-    return STATUS_INVALID_ARGS;
-}
-
-static int handle_flag_R(const wchar_t **argv, parser_t &parser, io_streams_t &streams,
-                         const wgetopter_t &w, options_t *opts) {
-    if (opts->relative_valid) {
-        opts->relative = true;
-        return STATUS_CMD_OK;
-    }
-    path_unknown_option(parser, streams, argv[0], argv[w.woptind - 1]);
-    return STATUS_INVALID_ARGS;
-}
-
-static int handle_flag_r(const wchar_t **argv, parser_t &parser, io_streams_t &streams,
-                         const wgetopter_t &w, options_t *opts) {
-    if (opts->reverse_valid) {
-        opts->reverse = true;
-        return STATUS_CMD_OK;
-    } else if (opts->perm_valid) {
-        return handle_flag_perms(argv, parser, streams, w, opts, PERM_READ);
-    }
-    path_unknown_option(parser, streams, argv[0], argv[w.woptind - 1]);
-    return STATUS_INVALID_ARGS;
-}
-
-static int handle_flag_w(const wchar_t **argv, parser_t &parser, io_streams_t &streams,
-                         const wgetopter_t &w, options_t *opts) {
-    return handle_flag_perms(argv, parser, streams, w, opts, PERM_WRITE);
-}
-static int handle_flag_x(const wchar_t **argv, parser_t &parser, io_streams_t &streams,
-                         const wgetopter_t &w, options_t *opts) {
-    return handle_flag_perms(argv, parser, streams, w, opts, PERM_EXEC);
-}
-
-static int handle_flag_types(const wchar_t **argv, parser_t &parser, io_streams_t &streams,
-                             const wgetopter_t &w, options_t *opts, path_type_flags_t type) {
-    if (opts->type_valid) {
-        if (!opts->have_type) opts->type = 0;
-        opts->have_type = true;
-        opts->type |= type;
-        return STATUS_CMD_OK;
-    }
-    path_unknown_option(parser, streams, argv[0], argv[w.woptind - 1]);
-    return STATUS_INVALID_ARGS;
-}
-
-static int handle_flag_f(const wchar_t **argv, parser_t &parser, io_streams_t &streams,
-                         const wgetopter_t &w, options_t *opts) {
-    return handle_flag_types(argv, parser, streams, w, opts, TYPE_FILE);
-}
-static int handle_flag_l(const wchar_t **argv, parser_t &parser, io_streams_t &streams,
-                         const wgetopter_t &w, options_t *opts) {
-    return handle_flag_types(argv, parser, streams, w, opts, TYPE_LINK);
-}
-static int handle_flag_d(const wchar_t **argv, parser_t &parser, io_streams_t &streams,
-                         const wgetopter_t &w, options_t *opts) {
-    return handle_flag_types(argv, parser, streams, w, opts, TYPE_DIR);
-}
-
-static int handle_flag_v(const wchar_t **argv, parser_t &parser, io_streams_t &streams,
-                         const wgetopter_t &w, options_t *opts) {
-    if (opts->invert_valid) {
-        opts->invert = true;
-        return STATUS_CMD_OK;
-    }
-    path_unknown_option(parser, streams, argv[0], argv[w.woptind - 1]);
-    return STATUS_INVALID_ARGS;
-}
-
-static int handle_flag_u(const wchar_t **argv, parser_t &parser, io_streams_t &streams,
-                         const wgetopter_t &w, options_t *opts) {
-    if (opts->unique_valid) {
-        opts->unique = true;
-        return STATUS_CMD_OK;
-    }
-    path_unknown_option(parser, streams, argv[0], argv[w.woptind - 1]);
-    return STATUS_INVALID_ARGS;
-}
-
-static int handle_flag_key(const wchar_t **argv, parser_t &parser, io_streams_t &streams,
-                           const wgetopter_t &w, options_t *opts) {
-    UNUSED(argv);
-    UNUSED(parser);
-    UNUSED(streams);
-    opts->have_key = true;
-    opts->key = w.woptarg;
-    return STATUS_CMD_OK;
-}
-
-/// This constructs the wgetopt() short options string based on which arguments are valid for the
-/// subcommand. We have to do this because many short flags have multiple meanings and may or may
-/// not require an argument depending on the meaning.
-static wcstring construct_short_opts(options_t *opts) {  //!OCLINT(high npath complexity)
-    // All commands accept -z, -Z and -q
-    wcstring short_opts(L":zZq");
-    if (opts->perm_valid) {
-        short_opts.append(L"p:");
-        short_opts.append(L"rwx");
-    }
-    if (opts->type_valid) {
-        short_opts.append(L"t:");
-        short_opts.append(L"fld");
-    }
-    if (opts->invert_valid) short_opts.append(L"v");
-    if (opts->relative_valid) short_opts.append(L"R");
-    if (opts->reverse_valid) short_opts.append(L"r");
-    if (opts->unique_valid) short_opts.append(L"u");
-    return short_opts;
-}
-
-// Note that several long flags share the same short flag. That is okay. The caller is expected
-// to indicate that a max of one of the long flags sharing a short flag is valid.
-// Remember: adjust the completions in share/completions/ when options change
-static const struct woption long_options[] = {{L"quiet", no_argument, 'q'},
-                                              {L"null-in", no_argument, 'z'},
-                                              {L"null-out", no_argument, 'Z'},
-                                              {L"perm", required_argument, 'p'},
-                                              {L"type", required_argument, 't'},
-                                              {L"invert", no_argument, 'v'},
-                                              {L"relative", no_argument, 'R'},
-                                              {L"reverse", no_argument, 'r'},
-                                              {L"unique", no_argument, 'u'},
-                                              {L"key", required_argument, 1},
-                                              {}};
-
-static const std::unordered_map<char, decltype(*handle_flag_q)> flag_to_function = {
-    {'q', handle_flag_q}, {'v', handle_flag_v}, {'z', handle_flag_z}, {'Z', handle_flag_Z},
-    {'t', handle_flag_t}, {'p', handle_flag_p}, {'r', handle_flag_r}, {'w', handle_flag_w},
-    {'x', handle_flag_x}, {'f', handle_flag_f}, {'l', handle_flag_l}, {'d', handle_flag_d},
-    {'l', handle_flag_l}, {'d', handle_flag_d}, {'u', handle_flag_u}, {1, handle_flag_key},
-    {'R', handle_flag_R},
-};
-
-/// Parse the arguments for flags recognized by a specific string subcommand.
-static int parse_opts(options_t *opts, int *optind, int n_req_args, int argc, const wchar_t **argv,
-                      parser_t &parser, io_streams_t &streams) {
-    const wchar_t *cmd = argv[0];
-    wcstring short_opts = construct_short_opts(opts);
-    const wchar_t *short_options = short_opts.c_str();
-    int opt;
-    wgetopter_t w;
-    while ((opt = w.wgetopt_long(argc, argv, short_options, long_options, nullptr)) != -1) {
-        auto fn = flag_to_function.find(opt);
-        if (fn != flag_to_function.end()) {
-            int retval = fn->second(argv, parser, streams, w, opts);
-            if (retval != STATUS_CMD_OK) return retval;
-        } else if (opt == ':') {
-            streams.err.append(L"path ");
-            builtin_missing_argument(parser, streams, cmd, argv[w.woptind - 1],
-                                     false /* print_hints */);
-            return STATUS_INVALID_ARGS;
-        } else if (opt == '?') {
-            path_unknown_option(parser, streams, cmd, argv[w.woptind - 1]);
-            return STATUS_INVALID_ARGS;
-        } else {
-            DIE("unexpected retval from wgetopt_long");
-        }
-    }
-
-    *optind = w.woptind;
-
-    if (n_req_args) {
-        assert(n_req_args == 1);
-        opts->arg1 = path_get_arg_argv(optind, argv);
-        if (!opts->arg1 && n_req_args == 1) {
-            path_error(streams, BUILTIN_ERR_ARG_COUNT0, cmd);
-            return STATUS_INVALID_ARGS;
-        }
-    }
-
-    // At this point we should not have optional args and be reading args from stdin.
-    if (path_args_from_stdin(streams) && argc > *optind) {
-        path_error(streams, BUILTIN_ERR_TOO_MANY_ARGUMENTS, cmd);
-        return STATUS_INVALID_ARGS;
-    }
-
-    return STATUS_CMD_OK;
-}
-
-static int path_transform(parser_t &parser, io_streams_t &streams, int argc, const wchar_t **argv,
-                          wcstring (*func)(wcstring)) {
-    options_t opts;
-    int optind;
-    int retval = parse_opts(&opts, &optind, 0, argc, argv, parser, streams);
-    if (retval != STATUS_CMD_OK) return retval;
-
-    int n_transformed = 0;
-    arg_iterator_t aiter(argv, optind, streams, opts.null_in);
-    while (const wcstring *arg = aiter.nextstr()) {
-        // Empty paths make no sense, but e.g. wbasename returns true for them.
-        if (arg->empty()) continue;
-        wcstring transformed = func(*arg);
-        if (transformed != *arg) {
-            n_transformed++;
-            // Return okay if path wasn't already in this form
-            // TODO: Is that correct?
-            if (opts.quiet) return STATUS_CMD_OK;
-        }
-        path_out(streams, opts, transformed);
-    }
-
-    return n_transformed > 0 ? STATUS_CMD_OK : STATUS_CMD_ERROR;
-}
-
-static int path_basename(parser_t &parser, io_streams_t &streams, int argc, const wchar_t **argv) {
-    return path_transform(parser, streams, argc, argv, wbasename);
-}
-
-static int path_dirname(parser_t &parser, io_streams_t &streams, int argc, const wchar_t **argv) {
-    return path_transform(parser, streams, argc, argv, wdirname);
-}
-
-// Not a constref because this must have the same type as wdirname.
-// cppcheck-suppress passedByValue
-static wcstring normalize_helper(wcstring path) {
-    wcstring np = normalize_path(path, false);
-    if (!np.empty() && np[0] == L'-') {
-        np = L"./" + np;
-    }
-    return np;
-}
-
-static bool filter_path(options_t opts, const wcstring &path) {
-    // TODO: Add moar stuff:
-    // fifos, sockets, size greater than zero, setuid, ...
-    // Nothing to check, file existence is checked elsewhere.
-    if (!opts.have_type && !opts.have_perm) return true;
-
-    if (opts.have_type) {
-        bool type_ok = false;
-        struct stat buf;
-        if (opts.type & TYPE_LINK) {
-            type_ok = !lwstat(path, &buf) && S_ISLNK(buf.st_mode);
-        }
-
-        auto ret = !wstat(path, &buf);
-        if (!ret) {
-            // Does not exist
-            return false;
-        }
-        if (!type_ok && opts.type & TYPE_FILE && S_ISREG(buf.st_mode)) {
-            type_ok = true;
-        }
-        if (!type_ok && opts.type & TYPE_DIR && S_ISDIR(buf.st_mode)) {
-            type_ok = true;
-        }
-        if (!type_ok && opts.type & TYPE_BLOCK && S_ISBLK(buf.st_mode)) {
-            type_ok = true;
-        }
-        if (!type_ok && opts.type & TYPE_CHAR && S_ISCHR(buf.st_mode)) {
-            type_ok = true;
-        }
-        if (!type_ok && opts.type & TYPE_FIFO && S_ISFIFO(buf.st_mode)) {
-            type_ok = true;
-        }
-        if (!type_ok && opts.type & TYPE_SOCK && S_ISSOCK(buf.st_mode)) {
-            type_ok = true;
-        }
-        if (!type_ok) return false;
-    }
-    if (opts.have_perm) {
-        int amode = 0;
-        if (opts.perm & PERM_READ) amode |= R_OK;
-        if (opts.perm & PERM_WRITE) amode |= W_OK;
-        if (opts.perm & PERM_EXEC) amode |= X_OK;
-        // access returns 0 on success,
-        // -1 on failure. Yes, C can't even keep its bools straight.
-        if (waccess(path, amode)) return false;
-
-        // Permissions that require special handling
-        if (opts.have_special_perm) {
-            struct stat buf;
-            auto ret = !wstat(path, &buf);
-            if (!ret) {
-                // Does not exist, WTF?
-                return false;
-            }
-
-            if (opts.perm & PERM_SUID && !(S_ISUID & buf.st_mode)) return false;
-            if (opts.perm & PERM_SGID && !(S_ISGID & buf.st_mode)) return false;
-            if (opts.perm & PERM_USER && !(geteuid() == buf.st_uid)) return false;
-            if (opts.perm & PERM_GROUP && !(getegid() == buf.st_gid)) return false;
-        }
-    }
-
-    // No filters failed.
-    return true;
-}
-
-static int path_mtime(parser_t &parser, io_streams_t &streams, int argc, const wchar_t **argv) {
-    options_t opts;
-    opts.relative_valid = true;
-    int optind;
-    int retval = parse_opts(&opts, &optind, 0, argc, argv, parser, streams);
-    if (retval != STATUS_CMD_OK) return retval;
-
-    int n_transformed = 0;
-
-    time_t t = std::time(nullptr);
-
-    arg_iterator_t aiter(argv, optind, streams, opts.null_in);
-    while (const wcstring *arg = aiter.nextstr()) {
-        auto ret = file_id_for_path(*arg);
-
-        if (ret != kInvalidFileID) {
-            if (opts.quiet) return STATUS_CMD_OK;
-            n_transformed++;
-
-            if (!opts.relative) {
-                path_out(streams, opts, to_string(ret.mod_seconds));
-            } else {
-                path_out(streams, opts, to_string(t - ret.mod_seconds));
-            }
-        }
-    }
-
-    return n_transformed > 0 ? STATUS_CMD_OK : STATUS_CMD_ERROR;
-}
-
-static int path_normalize(parser_t &parser, io_streams_t &streams, int argc, const wchar_t **argv) {
-    return path_transform(parser, streams, argc, argv, normalize_helper);
-}
-
-static maybe_t<size_t> find_extension(const wcstring &path) {
-    // The extension belongs to the basename,
-    // if there is a "." before the last component it doesn't matter.
-    // e.g. ~/.config/fish/conf.d/foo
-    // does not have an extension! The ".d" here is not a file extension for "foo".
-    // And "~/.config" doesn't have an extension either - the ".config" is the filename.
-    wcstring filename = wbasename(path);
-
-    // "." and ".." aren't really *files* and therefore don't have an extension.
-    if (filename == L"." || filename == L"..") return none();
-
-    // If we don't have a "." or the "." is the first in the filename,
-    // we do not have an extension
-    size_t pos = filename.find_last_of(L'.');
-    if (pos == wcstring::npos || pos == 0) {
-        return none();
-    }
-
-    // Convert pos back to what it would be in the original path.
-    return pos + path.size() - filename.size();
-}
-
-static int path_extension(parser_t &parser, io_streams_t &streams, int argc, const wchar_t **argv) {
-    options_t opts;
-    int optind;
-    int retval = parse_opts(&opts, &optind, 0, argc, argv, parser, streams);
-    if (retval != STATUS_CMD_OK) return retval;
-
-    int n_transformed = 0;
-    arg_iterator_t aiter(argv, optind, streams, opts.null_in);
-    while (const wcstring *arg = aiter.nextstr()) {
-        auto pos = find_extension(*arg);
-
-        if (!pos.has_value()) {
-            // If there is no extension the extension is empty.
-            // This is unambiguous because we include the ".".
-            path_out(streams, opts, L"");
-            continue;
-        }
-
-        wcstring ext = arg->substr(*pos);
-        if (opts.quiet && !ext.empty()) {
-            return STATUS_CMD_OK;
-        }
-        path_out(streams, opts, ext);
-        n_transformed++;
-    }
-
-    return n_transformed > 0 ? STATUS_CMD_OK : STATUS_CMD_ERROR;
-}
-
-static int path_change_extension(parser_t &parser, io_streams_t &streams, int argc,
-                                 const wchar_t **argv) {
-    options_t opts;
-    int optind;
-    int retval = parse_opts(&opts, &optind, 1, argc, argv, parser, streams);
-    if (retval != STATUS_CMD_OK) return retval;
-
-    int n_transformed = 0;
-    arg_iterator_t aiter(argv, optind, streams, opts.null_in);
-    while (const wcstring *arg = aiter.nextstr()) {
-        auto pos = find_extension(*arg);
-
-        wcstring ext;
-        if (!pos.has_value()) {
-            ext = *arg;
-        } else {
-            ext = arg->substr(0, *pos);
-        }
-
-        // Only add on the extension "." if we have something.
-        // That way specifying an empty extension strips it.
-        if (*opts.arg1) {
-            if (opts.arg1[0] != L'.') {
-                ext.push_back(L'.');
-            }
-            ext.append(opts.arg1);
-        }
-        path_out(streams, opts, ext);
-        n_transformed++;
-    }
-
-    return n_transformed > 0 ? STATUS_CMD_OK : STATUS_CMD_ERROR;
-}
-
-static int path_resolve(parser_t &parser, io_streams_t &streams, int argc, const wchar_t **argv) {
-    options_t opts;
-    int optind;
-    int retval = parse_opts(&opts, &optind, 0, argc, argv, parser, streams);
-    if (retval != STATUS_CMD_OK) return retval;
-
-    int n_transformed = 0;
-    arg_iterator_t aiter(argv, optind, streams, opts.null_in);
-    while (const wcstring *arg = aiter.nextstr()) {
-        auto real = wrealpath(*arg);
-
-        if (!real) {
-            // The path doesn't exist, isn't readable or a symlink loop.
-            // We go up until we find something that works.
-            wcstring next = *arg;
-            // First add $PWD if we're relative
-            if (!next.empty() && next[0] != L'/') {
-                // Note pwd can have symlinks, but we are about to resolve it anyway.
-                next = path_apply_working_directory(*arg, parser.vars().get_pwd_slash());
-            }
-            auto rest = wbasename(next);
-            while (!next.empty() && next != L"/") {
-                next = wdirname(next);
-                real = wrealpath(next);
-                if (real) {
-                    real->push_back(L'/');
-                    real->append(rest);
-                    real = normalize_path(*real, false);
-                    break;
-                }
-                rest = wbasename(next) + L'/' + rest;
-            }
-            if (!real) {
-                continue;
-            }
-        }
-
-        // Normalize the path so "../" components are eliminated even after
-        // nonexistent or non-directory components.
-        // Otherwise `path resolve foo/../` will be `$PWD/foo/../` if foo is a file.
-        real = normalize_path(*real, false);
-
-        // Return 0 if we found a realpath.
-        if (opts.quiet) {
-            return STATUS_CMD_OK;
-        }
-        path_out(streams, opts, *real);
-        n_transformed++;
-    }
-
-    return n_transformed > 0 ? STATUS_CMD_OK : STATUS_CMD_ERROR;
-}
-
-static int path_sort(parser_t &parser, io_streams_t &streams, int argc, const wchar_t **argv) {
-    options_t opts;
-    opts.reverse_valid = true;
-    opts.key_valid = true;
-    opts.unique_valid = true;
-    int optind;
-    int retval = parse_opts(&opts, &optind, 0, argc, argv, parser, streams);
-    if (retval != STATUS_CMD_OK) return retval;
-
-    auto keyfunc = +[](const wcstring &x) { return wbasename(x); };
-    if (opts.have_key) {
-        if (std::wcscmp(opts.key, L"basename") == 0) {
-            // Do nothing, this is the default
-        } else if (std::wcscmp(opts.key, L"dirname") == 0) {
-            keyfunc = +[](const wcstring &x) { return wdirname(x); };
-        } else if (std::wcscmp(opts.key, L"path") == 0) {
-            // Act as if --key hadn't been given.
-            opts.have_key = false;
-        } else {
-            path_error(streams, _(L"%ls: Invalid sort key '%ls'\n"), argv[0], opts.key);
-            return STATUS_INVALID_ARGS;
-        }
-    }
-
-    std::vector<wcstring> list;
-    arg_iterator_t aiter(argv, optind, streams, opts.null_in);
-    while (const wcstring *arg = aiter.nextstr()) {
-        list.push_back(*arg);
-    }
-
-    if (opts.have_key) {
-        // Keep a map to avoid repeated keyfunc calls and to keep things alive.
-        std::map<wcstring, wcstring> key;
-        for (const auto &arg : list) {
-            key[arg] = keyfunc(arg);
-        }
-
-        // We use a stable sort here, and also explicit < and >,
-        // to avoid changing the order so you can chain calls.
-        std::stable_sort(list.begin(), list.end(), [&](const wcstring &a, const wcstring &b) {
-            if (!opts.reverse)
-                return (wcsfilecmp_glob(key[a].c_str(), key[b].c_str()) < 0);
-            else
-                return (wcsfilecmp_glob(key[a].c_str(), key[b].c_str()) > 0);
-        });
-        if (opts.unique) {
-            list.erase(
-                std::unique(list.begin(), list.end(),
-                            [&](const wcstring &a, const wcstring &b) { return key[a] == key[b]; }),
-                list.end());
-        }
-    } else {
-        // Without --key, we just sort by the entire path,
-        // so we have no need to transform and such.
-        std::stable_sort(list.begin(), list.end(), [&](const wcstring &a, const wcstring &b) {
-            if (!opts.reverse)
-                return (wcsfilecmp_glob(a.c_str(), b.c_str()) < 0);
-            else
-                return (wcsfilecmp_glob(a.c_str(), b.c_str()) > 0);
-        });
-        if (opts.unique) {
-            list.erase(std::unique(list.begin(), list.end()), list.end());
-        }
-    }
-
-    for (const auto &entry : list) {
-        path_out(streams, opts, entry);
-    }
-
-    /* TODO: Return true only if already sorted? */
-    return STATUS_CMD_OK;
-}
-
-// All strings are taken to be filenames, and if they match the type/perms/etc (and exist!)
-// they are passed along.
-static int path_filter(parser_t &parser, io_streams_t &streams, int argc, const wchar_t **argv,
-                       bool is_is) {
-    options_t opts;
-    opts.type_valid = true;
-    opts.perm_valid = true;
-    opts.invert_valid = true;
-    int optind;
-    int retval = parse_opts(&opts, &optind, 0, argc, argv, parser, streams);
-    if (retval != STATUS_CMD_OK) return retval;
-    // If we have been invoked as "path is", which is "path filter -q".
-    if (is_is) opts.quiet = true;
-
-    int n_transformed = 0;
-    arg_iterator_t aiter(argv, optind, streams, opts.null_in);
-    while (const wcstring *arg = aiter.nextstr()) {
-        if ((!opts.have_perm && !opts.have_type) || (filter_path(opts, *arg) != opts.invert)) {
-            // If we don't have filters, check if it exists.
-            if (!opts.have_type && !opts.have_perm) {
-                bool ok = !waccess(*arg, F_OK);
-                if (ok == opts.invert) continue;
-            }
-
-            // We *know* this is a filename,
-            // and so if it starts with a `-` we *know* it is relative
-            // to $PWD. So we can add `./`.
-            if (!arg->empty() && arg->front() == L'-') {
-                wcstring out = L"./" + *arg;
-                path_out(streams, opts, out);
-            } else {
-                path_out(streams, opts, *arg);
-            }
-            n_transformed++;
-            if (opts.quiet) return STATUS_CMD_OK;
-        }
-    }
-
-    return n_transformed > 0 ? STATUS_CMD_OK : STATUS_CMD_ERROR;
-}
-
-static int path_filter(parser_t &parser, io_streams_t &streams, int argc, const wchar_t **argv) {
-    return path_filter(parser, streams, argc, argv, false /* is_is */);
-}
-
-static int path_is(parser_t &parser, io_streams_t &streams, int argc, const wchar_t **argv) {
-    return path_filter(parser, streams, argc, argv, true /* is_is */);
-}
-
-// Keep sorted alphabetically
-static constexpr const struct path_subcommand {
-    const wchar_t *name;
-    int (*handler)(parser_t &, io_streams_t &, int argc,  //!OCLINT(unused param)
-                   const wchar_t **argv);                 //!OCLINT(unused param)
-} path_subcommands[] = {
-    // TODO: Which operations do we want?
-    {L"basename", &path_basename},  //
-    {L"change-extension", &path_change_extension},
-    {L"dirname", &path_dirname},
-    {L"extension", &path_extension},
-    {L"filter", &path_filter},
-    {L"is", &path_is},
-    {L"mtime", &path_mtime},
-    {L"normalize", &path_normalize},
-    {L"resolve", &path_resolve},
-    {L"sort", &path_sort},
-};
-ASSERT_SORTED_BY_NAME(path_subcommands);
-
-/// The path builtin, for handling paths.
-maybe_t<int> builtin_path(parser_t &parser, io_streams_t &streams, const wchar_t **argv) {
-    const wchar_t *cmd = argv[0];
-    int argc = builtin_count_args(argv);
-    if (argc <= 1) {
-        streams.err.append_format(BUILTIN_ERR_MISSING_SUBCMD, cmd);
-        builtin_print_error_trailer(parser, streams.err, L"path");
-        return STATUS_INVALID_ARGS;
-    }
-
-    if (std::wcscmp(argv[1], L"-h") == 0 || std::wcscmp(argv[1], L"--help") == 0) {
-        builtin_print_help(parser, streams, L"path");
-        return STATUS_CMD_OK;
-    }
-
-    const wchar_t *subcmd_name = argv[1];
-    const auto *subcmd = get_by_sorted_name(subcmd_name, path_subcommands);
-    if (!subcmd) {
-        streams.err.append_format(BUILTIN_ERR_INVALID_SUBCMD, cmd, subcmd_name);
-        builtin_print_error_trailer(parser, streams.err, L"path");
-        return STATUS_INVALID_ARGS;
-    }
-
-    if (argc >= 3 && (std::wcscmp(argv[2], L"-h") == 0 || std::wcscmp(argv[2], L"--help") == 0)) {
-        // Unlike string, we don't have separate docs (yet)
-        builtin_print_help(parser, streams, L"path");
-        return STATUS_CMD_OK;
-    }
-    argc--;
-    argv++;
-    return subcmd->handler(parser, streams, argc, argv);
-}

src/builtins/path.h

@@ -1,10 +0,0 @@
-#ifndef FISH_BUILTIN_PATH_H
-#define FISH_BUILTIN_PATH_H
-
-#include "../maybe.h"
-
-class parser_t;
-struct io_streams_t;
-
-maybe_t<int> builtin_path(parser_t &parser, io_streams_t &streams, const wchar_t **argv);
-#endif