From 807bb530ecf6cde6c13956a20f64db32e86b892e Mon Sep 17 00:00:00 2001
From: Boris Kolpackov <boris@codesynthesis.com>
Date: Mon, 29 Aug 2016 18:51:07 +0200
Subject: Add flag to file_exists() not to follow symlinks

---
 butl/filesystem.cxx | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

(limited to 'butl/filesystem.cxx')

diff --git a/butl/filesystem.cxx b/butl/filesystem.cxx
index 5584e00..a47140d 100644
--- a/butl/filesystem.cxx
+++ b/butl/filesystem.cxx
@@ -34,16 +34,27 @@ using namespace std;
 
 namespace butl
 {
+#ifndef _WIN32
   bool
-  file_exists (const char* p)
+  file_exists (const char* p, bool fl)
   {
-#ifndef _WIN32
     struct stat s;
-    if (stat (p, &s) != 0)
+    if ((fl ? stat (p, &s) : lstat (p, &s)) != 0)
+    {
+      if (errno == ENOENT || errno == ENOTDIR)
+        return false;
+      else
+        throw system_error (errno, system_category ());
+    }
+
+    return S_ISREG (s.st_mode) || (!fl && S_ISLNK (s.st_mode));
+  }
 #else
+  bool
+  file_exists (const char* p, bool)
+  {
     struct _stat s;
     if (_stat (p, &s) != 0)
-#endif
     {
       if (errno == ENOENT || errno == ENOTDIR)
         return false;
@@ -53,6 +64,7 @@ namespace butl
 
     return S_ISREG (s.st_mode);
   }
+#endif
 
   bool
   dir_exists (const char* p)
@@ -172,6 +184,9 @@ namespace butl
     if (_unlink (p.string ().c_str ()) != 0)
 #endif
     {
+      // Strangely on Linux unlink() removes a dangling symlink but returns
+      // ENOENT.
+      //
       if (errno == ENOENT || errno == ENOTDIR)
         r = rmfile_status::not_exist;
       else if (!ignore_error)
-- 
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