Improved file tools

It is now possible to enforce the suffix of a file.
Additionally, there is a check so that files named "/dev/null"
are not added any suffix nor backed up.

These changes are useful to implement single-file multiple walkers

src/tools/FileBase.cpp

@@ -100,10 +100,8 @@ FileBase& FileBase::link(Action&action){
 bool FileBase::FileExist(const std::string& path){
   FILE *ff=NULL;
   bool do_exist=false;
-  if(plumed){
-    this->path=appendSuffix(path,plumed->getSuffix());
-    ff=std::fopen(const_cast<char*>(this->path.c_str()),"r");
-  }
+  this->path=appendSuffix(path,getSuffix());
+  ff=std::fopen(const_cast<char*>(this->path.c_str()),"r");
   if(!ff){
     this->path=path;
     ff=std::fopen(const_cast<char*>(this->path.c_str()),"r");
@@ -140,7 +138,8 @@ FileBase::FileBase():
   cloned(false),
   eof(false),
   err(false),
-  heavyFlush(false)
+  heavyFlush(false),
+  enforcedSuffix_(false)
 {
 }
 
@@ -158,6 +157,7 @@ FileBase::operator bool()const{
 }
 
 std::string FileBase::appendSuffix(const std::string&path,const std::string&suffix){
+  if(path=="/dev/null") return path; // do not append a suffix to /dev/null
   std::string ret=path;
   std::string ext=Tools::extension(path);
   if(ext=="gz"){
@@ -170,7 +170,16 @@ std::string FileBase::appendSuffix(const std::string&path,const std::string&suff
   return ret;
 }
 
+FileBase& FileBase::enforceSuffix(const std::string&suffix){
+  enforcedSuffix_=true;
+  enforcedSuffix=suffix;
+  return *this;
+}
 
-
+std::string FileBase::getSuffix()const{
+  if(enforcedSuffix_) return enforcedSuffix;
+  if(plumed) return plumed->getSuffix();
+  return "";
+}
 
 }

src/tools/FileBase.h

@@ -81,6 +81,11 @@ protected:
 /// It appends the desired suffix to the string. Notice that
 /// it conserves a possible ".gz" suffix.
   static std::string appendSuffix(const std::string&path,const std::string&suffix);
+private:
+/// Enforced suffix:
+  std::string enforcedSuffix;
+/// If true, use enforcedSuffix, else get it from PlumedMain
+  bool enforcedSuffix_;
 public:
 /// Link to an already open filed
   FileBase& link(FILE*);
@@ -92,6 +97,9 @@ public:
 /// Link to an Action object.
 /// Automatically links also the corresponding PlumedMain and Communicator.
   FileBase& link(Action&);
+/// Enforce suffix.
+/// Overrides the one set in PlumedMain&
+  FileBase& enforceSuffix(const std::string&suffix);
 /// Flushes the file to disk
   virtual FileBase& flush();
 /// Closes the file
@@ -111,6 +119,8 @@ public:
   bool FileExist(const std::string& path);
 /// Check if a file is open
   bool isOpen();
+/// Get the file suffix
+  std::string getSuffix()const;
 };
 
 

src/tools/OFile.cpp

@@ -234,9 +234,10 @@ void OFile::setBackupString( const std::string& str ){
 }
 
 void OFile::backupAllFiles( const std::string& str ){
+  if(str=="/dev/null") return;
   plumed_assert( backstring!="bck" && plumed && !plumed->getRestart() );
   size_t found=str.find_last_of("/\\");
-  std::string filename = appendSuffix(str,plumed->getSuffix());
+  std::string filename = appendSuffix(str,getSuffix());
   std::string directory=filename.substr(0,found+1);
   std::string file=filename.substr(found+1);
   if( FileExist(filename) ) backupFile("bck", filename);
@@ -249,6 +250,7 @@ void OFile::backupAllFiles( const std::string& str ){
 }
 
 void OFile::backupFile( const std::string& bstring, const std::string& fname ){
+   if(fname=="/dev/null") return;
    int maxbackup=100;
    if(std::getenv("PLUMED_MAXBACKUP")) Tools::convert(std::getenv("PLUMED_MAXBACKUP"),maxbackup);
    if(maxbackup>0 && (!comm || comm->Get_rank()==0)){
@@ -282,9 +284,7 @@ OFile& OFile::open(const std::string&path){
   fp=NULL;
   gzfp=NULL;
   this->path=path;
-  if(plumed){
-    this->path=appendSuffix(path,plumed->getSuffix());
-  }
+  this->path=appendSuffix(path,getSuffix());
   if(checkRestart()){
      fp=std::fopen(const_cast<char*>(this->path.c_str()),"a");
      if(Tools::extension(this->path)=="gz"){