lib/recursive_action.c

   1 /* vi: set sw=8 ts=8: */
   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 #ifdef __BAREBOX__
  10
  11 #include <common.h>
  12 #include <fs.h>
  13 #include <linux/stat.h>
  14 #include <malloc.h>
  15 #include <libbb.h>
  16
  17 #endif
  18
  19 /*
  20  * Walk down all the directories under the specified
  21  * location, and do something (something specified
  22  * by the fileAction and dirAction function pointers).
  23  *
  24  * Unfortunately, while nftw(3) could replace this and reduce
  25  * code size a bit, nftw() wasn't supported before GNU libc 2.1,
  26  * and so isn't sufficiently portable to take over since glibc2.1
  27  * is so stinking huge.
  28  */
  29
  30 static int true_action(const char *fileName, struct stat *statbuf,
  31                                                 void* userData, int depth)
  32 {
  33         return 1;
  34 }
  35
  36 /* fileAction return value of 0 on any file in directory will make
  37  * recursive_action() return 0, but it doesn't stop directory traversal
  38  * (fileAction/dirAction will be called on each file).
  39  *
  40  * if !depthFirst, dirAction return value of 0 (FALSE) or 2 (SKIP)
  41  * prevents recursion into that directory, instead
  42  * recursive_action() returns 0 (if FALSE) or 1 (if SKIP).
  43  *
  44  * followLinks=0/1 differs mainly in handling of links to dirs.
  45  * 0: lstat(statbuf). Calls fileAction on link name even if points to dir.
  46  * 1: stat(statbuf). Calls dirAction and optionally recurse on link to dir.
  47  */
  48
  49 int recursive_action(const char *fileName,
  50                 unsigned flags,
  51                 int (*fileAction)(const char *fileName, struct stat *statbuf, void* userData, int depth),
  52                 int (*dirAction)(const char *fileName, struct stat *statbuf, void* userData, int depth),
  53                 void* userData,
  54                 const unsigned depth)
  55 {
  56         struct stat statbuf;
  57         int status;
  58         DIR *dir;
  59         struct dirent *next;
  60
  61         if (!fileAction) fileAction = true_action;
  62         if (!dirAction) dirAction = true_action;
  63         status = stat(fileName, &statbuf);
  64
  65         if (status < 0) {
  66 #ifdef DEBUG_RECURS_ACTION
  67                 bb_error_msg("status=%d followLinks=%d TRUE=%d",
  68                                 status, flags & ACTION_FOLLOWLINKS, TRUE);
  69 #endif
  70                 goto done_nak_warn;
  71         }
  72
  73         /* If S_ISLNK(m), then we know that !S_ISDIR(m).
  74          * Then we can skip checking first part: if it is true, then
  75          * (!dir) is also true! */
  76         if ( /* (!(flags & ACTION_FOLLOWLINKS) && S_ISLNK(statbuf.st_mode)) || */
  77          !S_ISDIR(statbuf.st_mode)
  78         ) {
  79                 return fileAction(fileName, &statbuf, userData, depth);
  80         }
  81
  82         /* It's a directory (or a link to one, and followLinks is set) */
  83
  84         if (!(flags & ACTION_RECURSE)) {
  85                 return dirAction(fileName, &statbuf, userData, depth);
  86         }
  87
  88         if (!(flags & ACTION_DEPTHFIRST)) {
  89                 status = dirAction(fileName, &statbuf, userData, depth);
  90                 if (!status) {
  91                         goto done_nak_warn;
  92                 }
  93                 if (status == 2)
  94                         return 1;
  95         }
  96
  97         dir = opendir(fileName);
  98         if (!dir) {
  99                 /* findutils-4.1.20 reports this */
 100                 /* (i.e. it doesn't silently return with exit code 1) */
 101                 /* To trigger: "find -exec rm -rf {} \;" */
 102                 goto done_nak_warn;
 103         }
 104         status = 1;
 105         while ((next = readdir(dir)) != NULL) {
 106                 char *nextFile;
 107
 108                 nextFile = concat_subpath_file(fileName, next->d_name);
 109                 if (nextFile == NULL)
 110                         continue;
 111                 /* now descend into it, forcing recursion. */
 112                 if (!recursive_action(nextFile, flags | ACTION_RECURSE,
 113                                 fileAction, dirAction, userData, depth+1)) {
 114                         status = 0;
 115                 }
 116                 free(nextFile);
 117         }
 118         closedir(dir);
 119         if ((flags & ACTION_DEPTHFIRST) &&
 120                 !dirAction(fileName, &statbuf, userData, depth)) {
 121                         goto done_nak_warn;
 122         }
 123
 124         if (!status)
 125                 return 0;
 126         return 1;
 127 done_nak_warn:
 128         printf("%s", fileName);
 129         return 0;
 130 }
 131
 132 #ifdef __BAREBOX__
 133 EXPORT_SYMBOL(recursive_action);
 134 #endif