Additional code for clarification in reply to a comment ( https://stackoverflow.com/questions/10273816/how-to-check-whether-file-exists-in-qt-in-c/26991243?noredirect=1#comment86989399_26991243 )

file_check.cpp

QString path = "C:/test.pdf";  // this path points to an existing file
bool fileExists = QFileInfo::exists(path);
qDebug() << fileExists;  // true

// this path points to an existing directory
// (Caution: we want to check for a file, not a directory!)
path = "C:/Users";
fileExists = QFileInfo::exists(path);
qDebug() << fileExists;  // true (this is NOT what we want!)

path = "C:/non_existing_file.txt";  // this path points to no actual file
fileExists = QFileInfo::exists(path);
qDebug() << fileExists;  // false