source: MondoRescue/branches/3.2/mindi-busybox/libbb/recursive_action.c@ 3232

/* vi: set sw=4 ts=4: */
/*
 * Utility routines.
 *
 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

#include "libbb.h"

#undef DEBUG_RECURS_ACTION

/*
 * Walk down all the directories under the specified
 * location, and do something (something specified
 * by the fileAction and dirAction function pointers).
 *
 * Unfortunately, while nftw(3) could replace this and reduce
 * code size a bit, nftw() wasn't supported before GNU libc 2.1,
 * and so isn't sufficiently portable to take over since glibc2.1
 * is so stinking huge.
 */

static int FAST_FUNC true_action(const char *fileName UNUSED_PARAM,
        struct stat *statbuf UNUSED_PARAM,
        void* userData UNUSED_PARAM,
        int depth UNUSED_PARAM)
{
    return TRUE;
}

/* fileAction return value of 0 on any file in directory will make
 * recursive_action() return 0, but it doesn't stop directory traversal
 * (fileAction/dirAction will be called on each file).
 *
 * If !ACTION_RECURSE, dirAction is called on the directory and its
 * return value is returned from recursive_action(). No recursion.
 *
 * If ACTION_RECURSE, recursive_action() is called on each directory.
 * If any one of these calls returns 0, current recursive_action() returns 0.
 *
 * If ACTION_DEPTHFIRST, dirAction is called after recurse.
 * If it returns 0, the warning is printed and recursive_action() returns 0.
 *
 * If !ACTION_DEPTHFIRST, dirAction is called before we recurse.
 * Return value of 0 (FALSE) or 2 (SKIP) prevents recursion
 * into that directory, instead recursive_action() returns 0 (if FALSE)
 * or 1 (if SKIP)
 *
 * ACTION_FOLLOWLINKS mainly controls handling of links to dirs.
 * 0: lstat(statbuf). Calls fileAction on link name even if points to dir.
 * 1: stat(statbuf). Calls dirAction and optionally recurse on link to dir.
 */

int FAST_FUNC recursive_action(const char *fileName,
        unsigned flags,
        int FAST_FUNC (*fileAction)(const char *fileName, struct stat *statbuf, void* userData, int depth),
        int FAST_FUNC (*dirAction)(const char *fileName, struct stat *statbuf, void* userData, int depth),
        void* userData,
        unsigned depth)
{
    struct stat statbuf;
    unsigned follow;
    int status;
    DIR *dir;
    struct dirent *next;

    if (!fileAction) fileAction = true_action;
    if (!dirAction) dirAction = true_action;

    follow = ACTION_FOLLOWLINKS;
    if (depth == 0)
        follow = ACTION_FOLLOWLINKS | ACTION_FOLLOWLINKS_L0;
    follow &= flags;
    status = (follow ? stat : lstat)(fileName, &statbuf);
    if (status < 0) {
#ifdef DEBUG_RECURS_ACTION
        bb_error_msg("status=%d flags=%x", status, flags);
#endif
        if ((flags & ACTION_DANGLING_OK)
         && errno == ENOENT
         && lstat(fileName, &statbuf) == 0
        ) {
            /* Dangling link */
            return fileAction(fileName, &statbuf, userData, depth);
        }
        goto done_nak_warn;
    }

    /* If S_ISLNK(m), then we know that !S_ISDIR(m).
     * Then we can skip checking first part: if it is true, then
     * (!dir) is also true! */
    if ( /* (!(flags & ACTION_FOLLOWLINKS) && S_ISLNK(statbuf.st_mode)) || */
     !S_ISDIR(statbuf.st_mode)
    ) {
        return fileAction(fileName, &statbuf, userData, depth);
    }

    /* It's a directory (or a link to one, and followLinks is set) */

    if (!(flags & ACTION_RECURSE)) {
        return dirAction(fileName, &statbuf, userData, depth);
    }

    if (!(flags & ACTION_DEPTHFIRST)) {
        status = dirAction(fileName, &statbuf, userData, depth);
        if (!status)
            goto done_nak_warn;
        if (status == SKIP)
            return TRUE;
    }

    dir = opendir(fileName);
    if (!dir) {
        /* findutils-4.1.20 reports this */
        /* (i.e. it doesn't silently return with exit code 1) */
        /* To trigger: "find -exec rm -rf {} \;" */
        goto done_nak_warn;
    }
    status = TRUE;
    while ((next = readdir(dir)) != NULL) {
        char *nextFile;

        nextFile = concat_subpath_file(fileName, next->d_name);
        if (nextFile == NULL)
            continue;
        /* process every file (NB: ACTION_RECURSE is set in flags) */
        if (!recursive_action(nextFile, flags, fileAction, dirAction,
                        userData, depth + 1))
            status = FALSE;
//      s = recursive_action(nextFile, flags, fileAction, dirAction,
//                      userData, depth + 1);
        free(nextFile);
//#define RECURSE_RESULT_ABORT 3
//      if (s == RECURSE_RESULT_ABORT) {
//          closedir(dir);
//          return s;
//      }
//      if (s == FALSE)
//          status = FALSE;
    }
    closedir(dir);

    if (flags & ACTION_DEPTHFIRST) {
        if (!dirAction(fileName, &statbuf, userData, depth))
            goto done_nak_warn;
    }

    return status;

 done_nak_warn:
    if (!(flags & ACTION_QUIET))
        bb_simple_perror_msg(fileName);
    return FALSE;
}