The Annoyance Filter.pdf - Fourmilab

§136 ANNOYANCE-FILTER MAIL FOLDER 119
136. When we’re reading a mail folder consisting of a directory of individual mail messages, when we
reach the end of a message file we wish to seamlessly advance to the next file, logically concatenating
the files in the directory. This method, which should be called whenever the next file in the directory
is required, searches the directory for the next eligible file and opens it. We return true if the file was
opened successfully and false if the end of the directory was hit whilst looking for the next file.
〈 Class implementations 11 〉 +≡
#ifdef HAVE_DIRECTORY_TRAVERSAL
bool mailFolder ::findNextFileInDirectory (string &fname )
{
assert(dirFolder );
if (dh ≡ Λ) {
return false ; /∗ End of directory already encountered ∗/
}
while (true ) {
struct dirent ∗de ;
struct stat fs ;
de = readdir (dh );
if (de ≡ Λ) {
closedir (dh );
dh = Λ;
return false ;
}
cfName = dirName + pathSeparator + de ⃗ d name ;
if (stat (cfName .c str ( ), &fs ) ≡ 0) {
if (S_ISREG(fs .st mode )) {
fname = cfName ;
return openNextFileInDirectory ( );
}
}
else {
if (verbose ) {
cerr ≪ "Cannot␣get␣status␣of␣" ≪ cfName ≪ ".␣␣Skipping." ≪ endl ;
}
}
}
}
#endif