Make improvements

- Introduce path module to redbean
- Fix glitch with linenoise printing extra line on eof
- Introduce closefrom() and close_range() system calls
- Make file descriptor closing more secure in pledge.com

tool/net/lpath.c

@@ -0,0 +1,166 @@
+/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
+│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :vi│
+╞══════════════════════════════════════════════════════════════════════════════╡
+│ Copyright 2022 Justine Alexandra Roberts Tunney                              │
+│                                                                              │
+│ Permission to use, copy, modify, and/or distribute this software for         │
+│ any purpose with or without fee is hereby granted, provided that the         │
+│ above copyright notice and this permission notice appear in all copies.      │
+│                                                                              │
+│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                │
+│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                │
+│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             │
+│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         │
+│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        │
+│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               │
+│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             │
+│ PERFORMANCE OF THIS SOFTWARE.                                                │
+╚─────────────────────────────────────────────────────────────────────────────*/
+#include "libc/calls/struct/stat.h"
+#include "libc/errno.h"
+#include "libc/sysv/consts/at.h"
+#include "libc/sysv/consts/s.h"
+#include "third_party/lua/lauxlib.h"
+
+/**
+ * @fileoverview redbean unix path manipulation module
+ */
+
+// path.basename(str)
+//     └─→ str
+static int LuaPathBasename(lua_State *L) {
+  size_t i, n;
+  const char *p;
+  if ((p = luaL_optlstring(L, 1, 0, &n)) && n) {
+    while (n > 1 && p[n - 1] == '/') --n;
+    i = n - 1;
+    while (i && p[i - 1] != '/') --i;
+    lua_pushlstring(L, p + i, n - i);
+  } else {
+    lua_pushlstring(L, ".", 1);
+  }
+  return 1;
+}
+
+// path.dirname(str)
+//     └─→ str
+static int LuaPathDirname(lua_State *L) {
+  size_t n;
+  const char *p;
+  if ((p = luaL_optlstring(L, 1, 0, &n)) && n--) {
+    for (; p[n] == '/'; n--) {
+      if (!n) goto ReturnSlash;
+    }
+    for (; p[n] != '/'; n--) {
+      if (!n) goto ReturnDot;
+    }
+    for (; p[n] == '/'; n--) {
+      if (!n) goto ReturnSlash;
+    }
+    lua_pushlstring(L, p, n + 1);
+    return 1;
+  }
+ReturnDot:
+  lua_pushlstring(L, ".", 1);
+  return 1;
+ReturnSlash:
+  lua_pushlstring(L, "/", 1);
+  return 1;
+}
+
+// path.join(str, ...)
+//     └─→ str
+static int LuaPathJoin(lua_State *L) {
+  int i, n;
+  size_t z;
+  bool gotstr;
+  const char *c;
+  luaL_Buffer b;
+  bool needslash;
+  if ((n = lua_gettop(L))) {
+    luaL_buffinit(L, &b);
+    gotstr = false;
+    needslash = false;
+    for (i = 1; i <= n; ++i) {
+      if (lua_isnoneornil(L, i)) continue;
+      gotstr = true;
+      c = luaL_checklstring(L, i, &z);
+      if (z) {
+        if (c[0] == '/') {
+          luaL_buffsub(&b, luaL_bufflen(&b));
+        } else if (needslash) {
+          luaL_addchar(&b, '/');
+        }
+        luaL_addlstring(&b, c, z);
+        needslash = c[z - 1] != '/';
+      } else if (needslash) {
+        luaL_addchar(&b, '/');
+        needslash = false;
+      }
+    }
+    if (gotstr) {
+      luaL_pushresult(&b);
+    } else {
+      lua_pushnil(L);
+    }
+    return 1;
+  } else {
+    luaL_error(L, "missing argument");
+    unreachable;
+  }
+}
+
+static int CheckPath(lua_State *L, int type, int flags) {
+  int olderr;
+  struct stat st;
+  const char *path;
+  path = luaL_checkstring(L, 1);
+  olderr = errno;
+  if (fstatat(AT_FDCWD, path, &st, flags) != -1) {
+    lua_pushboolean(L, !type || (st.st_mode & S_IFMT) == type);
+  } else {
+    errno = olderr;
+    lua_pushboolean(L, false);
+  }
+  return 1;
+}
+
+// path.exists(str)
+//     └─→ bool
+static int LuaPathExists(lua_State *L) {
+  return CheckPath(L, 0, 0);
+}
+
+// path.isfile(str)
+//     └─→ bool
+static int LuaPathIsfile(lua_State *L) {
+  return CheckPath(L, S_IFREG, AT_SYMLINK_NOFOLLOW);
+}
+
+// path.islink(str)
+//     └─→ bool
+static int LuaPathIslink(lua_State *L) {
+  return CheckPath(L, S_IFLNK, AT_SYMLINK_NOFOLLOW);
+}
+
+// path.isdir(str)
+//     └─→ bool
+static int LuaPathIsdir(lua_State *L) {
+  return CheckPath(L, S_IFDIR, AT_SYMLINK_NOFOLLOW);
+}
+
+static const luaL_Reg kLuaPath[] = {
+    {"basename", LuaPathBasename},  //
+    {"dirname", LuaPathDirname},    //
+    {"exists", LuaPathExists},      //
+    {"isdir", LuaPathIsdir},        //
+    {"isfile", LuaPathIsfile},      //
+    {"islink", LuaPathIslink},      //
+    {"join", LuaPathJoin},          //
+    {0},                            //
+};
+
+int LuaPath(lua_State *L) {
+  luaL_newlib(L, kLuaPath);
+  return 1;
+}