Add base::ExecutableExistsInPath

base/files/file_util_posix.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/files/file_util.h"
 
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <libgen.h>
 #include <limits.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/errno.h>
 #include <sys/mman.h>
 #include <sys/param.h>
 #include <sys/stat.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <time.h>
 #include <unistd.h>
 
+#include "base/environment.h"
 #include "base/files/file_enumerator.h"
 #include "base/files/file_path.h"
 #include "base/files/scoped_file.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/singleton.h"
 #include "base/path_service.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/stl_util.h"
+#include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/sys_info.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/time/time.h"
 #include "build/build_config.h"
 
 #if defined(OS_MACOSX)
@@ skipping 404 matching lines @@
   // Clears the existing permission bits, and adds the new ones.
   mode_t updated_mode_bits = stat_buf.st_mode & ~FILE_PERMISSION_MASK;
   updated_mode_bits |= mode & FILE_PERMISSION_MASK;
 
   if (HANDLE_EINTR(chmod(path.value().c_str(), updated_mode_bits)) != 0)
     return false;
 
   return true;
 }
 
+bool ExecutableExistsInPath(Environment* env,
+                            const FilePath::StringType& executable) {
+  std::string path;
+  if (!env->GetVar("PATH", &path)) {
+    LOG(ERROR) << "No $PATH variable. Assuming no " << executable << ".";
+    return false;
+  }
+
+  for (const StringPiece& cur_path :
+       SplitStringPiece(path, ":", KEEP_WHITESPACE, SPLIT_WANT_NONEMPTY)) {
+    FilePath file(cur_path);
+    int permissions;
+    if (GetPosixFilePermissions(file.Append(executable), &permissions) &&
+        (permissions & FILE_PERMISSION_EXECUTE_BY_USER))
+      return true;
+  }
+  return false;
+}
+
 #if !defined(OS_MACOSX)
 // This is implemented in file_util_mac.mm for Mac.
 bool GetTempDir(FilePath* path) {
   const char* tmp = getenv("TMPDIR");
   if (tmp) {
     *path = FilePath(tmp);
   } else {
 #if defined(OS_ANDROID)
     return PathService::Get(base::DIR_CACHE, path);
 #else
@@ skipping 458 matching lines @@
     return false;
 
   DeleteFile(from_path, true);
   return true;
 }
 
 }  // namespace internal
 
 #endif  // !defined(OS_NACL_NONSFI)
 }  // namespace base