Add ability to restrict executable search to PATH only

3 files changed, 38 insertions, 24 deletions

diff --git a/libbutl/process.cxx b/libbutl/process.cxx
index 6f6ea8e..2260213 100644
--- a/libbutl/process.cxx
+++ b/libbutl/process.cxx
@@ -72,12 +72,12 @@ namespace butl
   // process
   //
   static process_path
-  path_search (const char*, const dir_path&);
+  path_search (const char*, const dir_path&, bool);
 
   process_path process::
-  path_search (const char* f, bool init, const dir_path& fb)
+  path_search (const char* f, bool init, const dir_path& fb, bool po)
   {
-    process_path r (try_path_search (f, init, fb));
+    process_path r (try_path_search (f, init, fb, po));
 
     if (r.empty ())
       throw process_error (ENOENT);
@@ -86,9 +86,9 @@ namespace butl
   }
 
   process_path process::
-  try_path_search (const char* f, bool init, const dir_path& fb)
+  try_path_search (const char* f, bool init, const dir_path& fb, bool po)
   {
-    process_path r (butl::path_search (f, fb));
+    process_path r (butl::path_search (f, fb, po));
 
     if (!init && !r.empty ())
     {
@@ -150,7 +150,7 @@ namespace butl
 #ifndef _WIN32
 
   static process_path
-  path_search (const char* f, const dir_path& fb)
+  path_search (const char* f, const dir_path& fb, bool)
   {
     // Note that there is a similar version for Win32.
 
@@ -614,7 +614,7 @@ namespace butl
 #else // _WIN32
 
   static process_path
-  path_search (const char* f, const dir_path& fb)
+  path_search (const char* f, const dir_path& fb, bool po)
   {
     // Note that there is a similar version for Win32.
 
@@ -731,6 +731,7 @@ namespace butl
     // The search order is documented in CreateProcess(). First we look in the
     // directory of the parent executable.
     //
+    if (!po)
     {
       char d[_MAX_PATH + 1];
       DWORD n (GetModuleFileName (NULL, d, _MAX_PATH + 1));
@@ -778,6 +779,7 @@ namespace butl
     // The recall path is the same as initial, though it might not be a bad
     // idea to prepend .\ for clarity.
     //
+    if (!po)
     {
       const string& d (traits::current_directory ());
 
diff --git a/libbutl/process.hxx b/libbutl/process.hxx
index cd692ca..3e1a990 100644
--- a/libbutl/process.hxx
+++ b/libbutl/process.hxx
@@ -313,8 +313,14 @@ namespace butl
     // This, for example, can be used to implement the Windows "search in the
     // parent executable's directory" semantics across platforms.
     //
+    // If path_only is true then only search in the PATH environment variable
+    // (or in CWD if there is a directory component) ignorting other places
+    // (like calling process' directory and, gasp, CWD on Windows).
+    //
     static process_path
-    path_search (const char*& args0, const dir_path& fallback = dir_path ());
+    path_search (const char*& args0,
+                 const dir_path& fallback = dir_path (),
+                 bool path_only = false);
 
     // This version is primarily useful when you want to pre-search the
     // executable before creating the args[] array. In this case you will
@@ -330,25 +336,31 @@ namespace butl
     // the same).
     //
     static process_path
-    path_search (const char* file, bool init, const dir_path& = dir_path ());
+    path_search (const char* file, bool init,
+                 const dir_path& = dir_path (), bool = false);
 
     static process_path
-    path_search (const std::string&, bool, const dir_path& = dir_path ());
+    path_search (const std::string&, bool,
+                 const dir_path& = dir_path (), bool = false);
 
     static process_path
-    path_search (const path&, bool, const dir_path& = dir_path ());
+    path_search (const path&, bool,
+                 const dir_path& = dir_path (), bool = false);
 
     // As above but if not found return empty process_path instead of
     // throwing.
     //
     static process_path
-    try_path_search (const char*, bool, const dir_path& = dir_path ());
+    try_path_search (const char*, bool,
+                     const dir_path& = dir_path (), bool = false);
 
     static process_path
-    try_path_search (const std::string&, bool, const dir_path& = dir_path ());
+    try_path_search (const std::string&, bool,
+                     const dir_path& = dir_path (), bool = false);
 
     static process_path
-    try_path_search (const path&, bool, const dir_path& = dir_path ());
+    try_path_search (const path&, bool,
+                     const dir_path& = dir_path (), bool = false);
 
     // Print process commmand line. If the number of elements is specified,
     // then it will print the piped multi-process command line, if present.
diff --git a/libbutl/process.ixx b/libbutl/process.ixx
index 4bdd438..1f1a2f4 100644
--- a/libbutl/process.ixx
+++ b/libbutl/process.ixx
@@ -90,9 +90,9 @@ namespace butl
 #endif
 
   inline process_path process::
-  path_search (const char*& a0, const dir_path& fb)
+  path_search (const char*& a0, const dir_path& fb, bool po)
   {
-    process_path r (path_search (a0, true, fb));
+    process_path r (path_search (a0, true, fb, po));
 
     if (!r.recall.empty ())
     {
@@ -104,27 +104,27 @@ namespace butl
   }
 
   inline process_path process::
-  path_search (const std::string& f, bool i, const dir_path& fb)
+  path_search (const std::string& f, bool i, const dir_path& fb, bool po)
   {
-    return path_search (f.c_str (), i, fb);
+    return path_search (f.c_str (), i, fb, po);
   }
 
   inline process_path process::
-  path_search (const path& f, bool i, const dir_path& fb)
+  path_search (const path& f, bool i, const dir_path& fb, bool po)
   {
-    return path_search (f.string ().c_str (), i, fb);
+    return path_search (f.string ().c_str (), i, fb, po);
   }
 
   inline process_path process::
-  try_path_search (const std::string& f, bool i, const dir_path& fb)
+  try_path_search (const std::string& f, bool i, const dir_path& fb, bool po)
   {
-    return try_path_search (f.c_str (), i, fb);
+    return try_path_search (f.c_str (), i, fb, po);
   }
 
   inline process_path process::
-  try_path_search (const path& f, bool i, const dir_path& fb)
+  try_path_search (const path& f, bool i, const dir_path& fb, bool po)
   {
-    return try_path_search (f.string ().c_str (), i, fb);
+    return try_path_search (f.string ().c_str (), i, fb, po);
   }
 
   inline process::