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phpfiledirectoryglob

How does glob() function work?

I know that glob() function is pretty slow but how does it work with the GLOB_ONLYDIR argument? Will it still check every file or it will use some index or whatever?

Solution

  • Looking at the source:

    /* we need to do this everytime since GLOB_ONLYDIR does not guarantee that
 * all directories will be filtered. GNU libc documentation states the
 * following: 
 * If the information about the type of the file is easily available 
 * non-directories will be rejected but no extra work will be done to 
 * determine the information for each file. I.e., the caller must still be 
 * able to filter directories out. 
 */
if (flags & GLOB_ONLYDIR) {
    struct stat s;

    if (0 != VCWD_STAT(globbuf.gl_pathv[n], &s)) {
        continue;
    }

    if (S_IFDIR != (s.st_mode & S_IFMT)) {
        continue;
    }
}

    So PHP has to check each file, regardless of whether it only asked for non-directory files.