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      1 /*
      2  * Copyright (c) 2003, 2004 Todd C. Miller <Todd.Miller (at) courtesan.com>
      3  *
      4  * Permission to use, copy, modify, and distribute this software for any
      5  * purpose with or without fee is hereby granted, provided that the above
      6  * copyright notice and this permission notice appear in all copies.
      7  *
      8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
      9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
     10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
     11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
     12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
     13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
     14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
     15  *
     16  * Sponsored in part by the Defense Advanced Research Projects
     17  * Agency (DARPA) and Air Force Research Laboratory, Air Force
     18  * Materiel Command, USAF, under agreement number F39502-99-1-0512.
     19  */
     20 
     21 #include <errno.h>
     22 #include <fts.h>
     23 #include <ftw.h>
     24 #include <sys/stat.h>
     25 #include <sys/types.h>
     26 #include <unistd.h>
     27 
     28 static int do_nftw(const char *path,
     29                    int (*ftw_fn)(const char*, const struct stat*, int),
     30                    int (*nftw_fn)(const char*, const struct stat*, int, FTW*),
     31                    int nfds,
     32                    int nftw_flags) {
     33   // TODO: nfds is currently unused.
     34   if (nfds < 1) {
     35     errno = EINVAL;
     36     return -1;
     37   }
     38 
     39   // Translate to fts_open options.
     40   int fts_options = FTS_LOGICAL | FTS_COMFOLLOW | FTS_NOCHDIR;
     41   if (nftw_fn) {
     42     fts_options = FTS_COMFOLLOW | ((nftw_flags & FTW_PHYS) ? FTS_PHYSICAL : FTS_LOGICAL);
     43     if (!(nftw_flags & FTW_CHDIR)) fts_options |= FTS_NOCHDIR;
     44     if (nftw_flags & FTW_MOUNT) fts_options |= FTS_XDEV;
     45   }
     46   bool postorder = (nftw_flags & FTW_DEPTH) != 0;
     47 
     48   // Call fts_open.
     49   char* const paths[2] = { const_cast<char*>(path), nullptr };
     50   FTS* fts = fts_open(paths, fts_options, nullptr);
     51   if (fts == nullptr) {
     52     return -1;
     53   }
     54 
     55   // Translate fts_read results into ftw/nftw callbacks.
     56   int error = 0;
     57   FTSENT* cur;
     58   while (error == 0 && (cur = fts_read(fts)) != nullptr) {
     59     int fn_flag;
     60     switch (cur->fts_info) {
     61       case FTS_D:
     62         // In the postorder case, we'll translate FTS_DP to FTW_DP later.
     63         // In the can't-access case, we'll translate FTS_DNR to FTW_DNR later.
     64         if (postorder || access(cur->fts_path, R_OK) == -1) continue;
     65         fn_flag = FTW_D;
     66         break;
     67       case FTS_DNR:
     68         fn_flag = FTW_DNR;
     69         break;
     70       case FTS_DP:
     71         if (!postorder) continue;
     72         fn_flag = FTW_DP;
     73         break;
     74       case FTS_F:
     75       case FTS_DEFAULT:
     76         fn_flag = FTW_F;
     77         break;
     78       case FTS_NS:
     79       case FTS_NSOK:
     80         fn_flag = FTW_NS;
     81         break;
     82       case FTS_SL:
     83         fn_flag = FTW_SL;
     84         break;
     85       case FTS_SLNONE:
     86         fn_flag = (nftw_fn != nullptr) ? FTW_SLN : FTW_NS;
     87         break;
     88       case FTS_DC:
     89         errno = ELOOP;
     90         error = -1;
     91         continue;
     92       default:
     93         error = -1;
     94         continue;
     95     }
     96 
     97     // Call the appropriate function.
     98     if (nftw_fn != nullptr) {
     99       FTW ftw;
    100       ftw.base = cur->fts_pathlen - cur->fts_namelen;
    101       ftw.level = cur->fts_level;
    102       error = nftw_fn(cur->fts_path, cur->fts_statp, fn_flag, &ftw);
    103     } else {
    104       error = ftw_fn(cur->fts_path, cur->fts_statp, fn_flag);
    105     }
    106   }
    107 
    108   int saved_errno = errno;
    109   if (fts_close(fts) != 0 && error == 0) {
    110     error = -1;
    111   } else {
    112     errno = saved_errno;
    113   }
    114   return error;
    115 }
    116 
    117 int ftw(const char* path, int (*ftw_fn)(const char*, const struct stat*, int), int nfds) {
    118   return do_nftw(path, ftw_fn, nullptr, nfds, 0);
    119 }
    120 
    121 int nftw(const char* path, int (*nftw_fn)(const char*, const struct stat*, int, FTW*),
    122          int nfds, int nftw_flags) {
    123   return do_nftw(path, nullptr, nftw_fn, nfds, nftw_flags);
    124 }
    125