0026781: Coding rules - eliminate GCC warning -Wunused-result

Check return code of fgets() and system() within FSD_BinaryFile::ReadChar(),
IFSelect_SessionFile::ReadFile(), IFSelect_SessionPilot::ReadScript(),
OSD_File::Print(), OSD_Process::Spawn(), RWStl::ReadAscii(), iges_lire().

src/FSD/FSD_BinaryFile.cxx

@@ -168,9 +168,8 @@ void FSD_BinaryFile::ReadChar(TCollection_AsciiString& buffer, const Standard_Si
   buffer.Clear();
 
   while (!IsEnd() && (ccount < rsize)) {
-    fread(&c, sizeof(char),1, myStream);
+    ccount += fread(&c, sizeof(char),1, myStream);
     buffer += c;
-    ccount++;
   }
 }
 

src/IFSelect/IFSelect_SessionFile.cxx

@@ -118,8 +118,11 @@ static int deja = 0;
   Standard_Boolean header = Standard_False;
   for(;;) {
     ligne[0] = '\0';
-    fgets(ligne,200,lefic);
+    if (fgets(ligne,200,lefic) == NULL
-    if (feof(lefic)) break;
+     || feof(lefic) != 0)
+    {
+      break;
+    }
     if (ligne[0] == '\0') continue;
 //  D abord ligne initiale ?
     if (!header)

src/IFSelect/IFSelect_SessionPilot.cxx

@@ -242,8 +242,11 @@ static TCollection_AsciiString nulword;
     char ligne[100];
     if (!lefic) std::cout << theprompt.ToCString();
     ligne[0] = '\0';
-    fgets(ligne,100,fic);
+    if (fgets(ligne,100,fic) == NULL
-    if (feof(fic)) break;
+     || feof(fic) != 0)
+    {
+      break;
+    }
     if (ligne[0] == '\0') continue;
 //    On interprete cette commande
     TCollection_AsciiString command(ligne);

src/IGESFile/liriges.c

@@ -44,7 +44,10 @@ int  iges_lire (FILE* lefic, int *numsec, char ligne[100], int modefnes)
 
     ligne[0] = '\0'; 
     if(modefnes)
-      fgets(ligne,99,lefic); /*for kept compatibility with fnes*/
+    {
+      if (fgets(ligne,99,lefic) == NULL) /*for kept compatibility with fnes*/
+        return 0;
+    }
     else
     {
       /* PTV: 21.03.2002 it is neccessary for files that have only `\r` but no `\n` 
@@ -53,7 +56,8 @@ int  iges_lire (FILE* lefic, int *numsec, char ligne[100], int modefnes)
       {
       }
       
-      fgets(&ligne[1],80,lefic);
+      if (fgets(&ligne[1],80,lefic) == NULL)
+        return 0;
     }
     
     if (*numsec == 0 && ligne[72] != 'S' && ligne[79] == ' ')
@@ -61,13 +65,17 @@ int  iges_lire (FILE* lefic, int *numsec, char ligne[100], int modefnes)
       ligne[0] = '\0';
       
       if(modefnes)
-        fgets(ligne,99,lefic);/*for kept compatibility with fnes*/
+      {
+        if (fgets(ligne,99,lefic) == NULL) /*for kept compatibility with fnes*/
+          return 0;
+      }
       else
       {
         while ( fgets ( ligne, 2, lefic ) && ( ligne[0] == '\r' || ligne[0] == '\n' ) )
         {
         }
-        fgets(&ligne[1],80,lefic);
+        if (fgets(&ligne[1],80,lefic) == NULL)
+          return 0;
       }
     }
 

src/OSD/OSD_File.cxx

@@ -750,7 +750,8 @@ TCollection_AsciiString PrinterName;
  else
    sprintf(buffer,"lpr -P%s %s",PrinterName.ToCString(),aBuffer.ToCString());
 
- system(buffer);
+ if (system(buffer) != 0)
+   Standard_ProgramError::Raise("OSD_File::Print : No output device was available, or an error occurred");
 }
 
 

src/OSD/OSD_Process.cxx

@@ -36,10 +36,10 @@ OSD_Process::OSD_Process(){
 }
 
 
-void OSD_Process::Spawn (const TCollection_AsciiString& cmd,
+Standard_Integer OSD_Process::Spawn (const TCollection_AsciiString& cmd,
 			 const Standard_Boolean /*ShowWindow*/)
 {
- system(cmd.ToCString());
+ return system(cmd.ToCString());
 }
 
 
@@ -206,11 +206,13 @@ OSD_Process :: OSD_Process () {
 
 }  // end constructor
 
-void OSD_Process :: Spawn ( const TCollection_AsciiString& cmd ,
+
+Standard_Integer OSD_Process::Spawn (const TCollection_AsciiString& cmd,
 			    const Standard_Boolean ShowWindow /* = Standard_True */) {
 
  STARTUPINFO         si;
  PROCESS_INFORMATION pi;
+ DWORD aRes = 0;
 
  ZeroMemory (  &si, sizeof ( STARTUPINFO )  );
 
@@ -229,20 +231,22 @@ void OSD_Process :: Spawn ( const TCollection_AsciiString& cmd ,
  if (!CreateProcess (
       NULL, (char *)cmd.ToCString (), NULL, NULL, TRUE, CREATE_NEW_CONSOLE, NULL, NULL, &si, &pi
                     )
- )
+ ) {
 
   _osd_wnt_set_error ( myError, OSD_WProcess );
-
+  aRes = myError.Error();
+ }
  else {
  
   CloseHandle ( pi.hThread );
 
   WaitForSingleObject ( pi.hProcess, INFINITE );
-
+  GetExitCodeProcess (pi.hProcess, &aRes);
   CloseHandle ( pi.hProcess );
  
  }  // end else
 
+ return aRes;
 }  // end OSD_Process :: Spawn
 
 void OSD_Process :: TerminalType ( TCollection_AsciiString& Name ) {

src/OSD/OSD_Process.hxx

@@ -43,7 +43,7 @@ public:
   
   //! Issues a shell command
   //! ShowWindow : flag to allow show/hide of the window ( only used on WNT )
-  Standard_EXPORT void Spawn (const TCollection_AsciiString& cmd, const Standard_Boolean ShowWindow = Standard_True);
+  Standard_EXPORT Standard_Integer Spawn (const TCollection_AsciiString& cmd, const Standard_Boolean ShowWindow = Standard_True);
   
   //! Returns the terminal used (vt100, vt200 ,sun-cmd ...)
   Standard_EXPORT void TerminalType (TCollection_AsciiString& Name);

src/RWStl/RWStl.cxx

@@ -495,7 +495,8 @@ Handle(StlMesh_Mesh) RWStl::ReadAscii (const OSD_Path& thePath,
     gp_XYZ aN (Atof(x), Atof(y), Atof(z));
 
     // skip the keywords "outer loop"
-    fscanf(file,"%*s %*s");
+    if (fscanf(file,"%*s %*s") < 0)
+      break;
 
     // reading vertex
     if (3 != fscanf(file,"%*s %80s %80s %80s\n", x, y, z))
@@ -516,10 +517,12 @@ Handle(StlMesh_Mesh) RWStl::ReadAscii (const OSD_Path& thePath,
     ReadMesh->AddTriangle (i1, i2, i3, aN.X(), aN.Y(), aN.Z());
 
     // skip the keywords "endloop"
-    fscanf(file,"%*s");
+    if (fscanf(file,"%*s") < 0)
+      break;
 
     // skip the keywords "endfacet"
-    fscanf(file,"%*s");
+    if (fscanf(file,"%*s") < 0)
+      break;
 
     // update progress only per 1k triangles
     if (++iTri % IND_THRESHOLD == 0)