LXR busybox/libbb/recursive

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * Utility routines.
   4 *
   5 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
   6 *
   7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
   8 */
   9
  10#include "libbb.h"
  11
  12#undef DEBUG_RECURS_ACTION
  13
  14/*
  15 * Walk down all the directories under the specified
  16 * location, and do something (something specified
  17 * by the fileAction and dirAction function pointers).
  18 *
  19 * Unfortunately, while nftw(3) could replace this and reduce
  20 * code size a bit, nftw() wasn't supported before GNU libc 2.1,
  21 * and so isn't sufficiently portable to take over since glibc2.1
  22 * is so stinking huge.
  23 */
  24
  25static int FAST_FUNC true_action(const char *fileName UNUSED_PARAM,
  26                struct stat *statbuf UNUSED_PARAM,
  27                void* userData UNUSED_PARAM,
  28                int depth UNUSED_PARAM)
  29{
  30        return TRUE;
  31}
  32
  33/* fileAction return value of 0 on any file in directory will make
  34 * recursive_action() return 0, but it doesn't stop directory traversal
  35 * (fileAction/dirAction will be called on each file).
  36 *
  37 * If !ACTION_RECURSE, dirAction is called on the directory and its
  38 * return value is returned from recursive_action(). No recursion.
  39 *
  40 * If ACTION_RECURSE, recursive_action() is called on each directory.
  41 * If any one of these calls returns 0, current recursive_action() returns 0.
  42 *
  43 * If ACTION_DEPTHFIRST, dirAction is called after recurse.
  44 * If it returns 0, the warning is printed and recursive_action() returns 0.
  45 *
  46 * If !ACTION_DEPTHFIRST, dirAction is called before we recurse.
  47 * Return value of 0 (FALSE) or 2 (SKIP) prevents recursion
  48 * into that directory, instead recursive_action() returns 0 (if FALSE)
  49 * or 1 (if SKIP)
  50 *
  51 * ACTION_FOLLOWLINKS mainly controls handling of links to dirs.
  52 * 0: lstat(statbuf). Calls fileAction on link name even if points to dir.
  53 * 1: stat(statbuf). Calls dirAction and optionally recurse on link to dir.
  54 */
  55
  56int FAST_FUNC recursive_action(const char *fileName,
  57                unsigned flags,
  58                int FAST_FUNC (*fileAction)(const char *fileName, struct stat *statbuf, void* userData, int depth),
  59                int FAST_FUNC (*dirAction)(const char *fileName, struct stat *statbuf, void* userData, int depth),
  60                void* userData,
  61                unsigned depth)
  62{
  63        struct stat statbuf;
  64        unsigned follow;
  65        int status;
  66        DIR *dir;
  67        struct dirent *next;
  68
  69        if (!fileAction) fileAction = true_action;
  70        if (!dirAction) dirAction = true_action;
  71
  72        follow = ACTION_FOLLOWLINKS;
  73        if (depth == 0)
  74                follow = ACTION_FOLLOWLINKS | ACTION_FOLLOWLINKS_L0;
  75        follow &= flags;
  76        status = (follow ? stat : lstat)(fileName, &statbuf);
  77        if (status < 0) {
  78#ifdef DEBUG_RECURS_ACTION
  79                bb_error_msg("status=%d flags=%x", status, flags);
  80#endif
  81                if ((flags & ACTION_DANGLING_OK)
  82                 && errno == ENOENT
  83                 && lstat(fileName, &statbuf) == 0
  84                ) {
  85                        /* Dangling link */
  86                        return fileAction(fileName, &statbuf, userData, depth);
  87                }
  88                goto done_nak_warn;
  89        }
  90
  91        /* If S_ISLNK(m), then we know that !S_ISDIR(m).
  92         * Then we can skip checking first part: if it is true, then
  93         * (!dir) is also true! */
  94        if ( /* (!(flags & ACTION_FOLLOWLINKS) && S_ISLNK(statbuf.st_mode)) || */
  95         !S_ISDIR(statbuf.st_mode)
  96        ) {
  97                return fileAction(fileName, &statbuf, userData, depth);
  98        }
  99
 100        /* It's a directory (or a link to one, and followLinks is set) */
 101
 102        if (!(flags & ACTION_RECURSE)) {
 103                return dirAction(fileName, &statbuf, userData, depth);
 104        }
 105
 106        if (!(flags & ACTION_DEPTHFIRST)) {
 107                status = dirAction(fileName, &statbuf, userData, depth);
 108                if (!status)
 109                        goto done_nak_warn;
 110                if (status == SKIP)
 111                        return TRUE;
 112        }
 113
 114        dir = opendir(fileName);
 115        if (!dir) {
 116                /* findutils-4.1.20 reports this */
 117                /* (i.e. it doesn't silently return with exit code 1) */
 118                /* To trigger: "find -exec rm -rf {} \;" */
 119                goto done_nak_warn;
 120        }
 121        status = TRUE;
 122        while ((next = readdir(dir)) != NULL) {
 123                char *nextFile;
 124
 125                nextFile = concat_subpath_file(fileName, next->d_name);
 126                if (nextFile == NULL)
 127                        continue;
 128                /* process every file (NB: ACTION_RECURSE is set in flags) */
 129                if (!recursive_action(nextFile, flags, fileAction, dirAction,
 130                                                userData, depth + 1))
 131                        status = FALSE;
 132//              s = recursive_action(nextFile, flags, fileAction, dirAction,
 133//                                              userData, depth + 1);
 134                free(nextFile);
 135//#define RECURSE_RESULT_ABORT 3
 136//              if (s == RECURSE_RESULT_ABORT) {
 137//                      closedir(dir);
 138//                      return s;
 139//              }
 140//              if (s == FALSE)
 141//                      status = FALSE;
 142        }
 143        closedir(dir);
 144
 145        if (flags & ACTION_DEPTHFIRST) {
 146                if (!dirAction(fileName, &statbuf, userData, depth))
 147                        goto done_nak_warn;
 148        }
 149
 150        return status;
 151
 152 done_nak_warn:
 153        if (!(flags & ACTION_QUIET))
 154                bb_simple_perror_msg(fileName);
 155        return FALSE;
 156}
 157