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      1 /*
      2  * Copyright (C) 2008 The Android Open Source Project
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions
      7  * are met:
      8  *  * Redistributions of source code must retain the above copyright
      9  *    notice, this list of conditions and the following disclaimer.
     10  *  * Redistributions in binary form must reproduce the above copyright
     11  *    notice, this list of conditions and the following disclaimer in
     12  *    the documentation and/or other materials provided with the
     13  *    distribution.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     16  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     17  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
     18  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
     19  * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
     22  * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
     25  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #include <libgen.h>
     30 
     31 #include <errno.h>
     32 #include <stdlib.h>
     33 #include <string.h>
     34 #include <sys/cdefs.h>
     35 #include <sys/param.h>
     36 
     37 #include "ThreadLocalBuffer.h"
     38 
     39 GLOBAL_INIT_THREAD_LOCAL_BUFFER(basename);
     40 GLOBAL_INIT_THREAD_LOCAL_BUFFER(dirname);
     41 
     42 char* basename(const char* path) {
     43   LOCAL_INIT_THREAD_LOCAL_BUFFER(char*, basename, MAXPATHLEN);
     44   int rc = basename_r(path, basename_tls_buffer, basename_tls_buffer_size);
     45   return (rc < 0) ? NULL : basename_tls_buffer;
     46 }
     47 
     48 char* dirname(const char* path) {
     49   LOCAL_INIT_THREAD_LOCAL_BUFFER(char*, dirname, MAXPATHLEN);
     50   int rc = dirname_r(path, dirname_tls_buffer, dirname_tls_buffer_size);
     51   return (rc < 0) ? NULL : dirname_tls_buffer;
     52 }
     53 
     54 int basename_r(const char* path, char* buffer, size_t buffer_size) {
     55   const char* startp = NULL;
     56   const char* endp = NULL;
     57   int len;
     58   int result;
     59 
     60   // Empty or NULL string gets treated as ".".
     61   if (path == NULL || *path == '\0') {
     62     startp = ".";
     63     len = 1;
     64     goto Exit;
     65   }
     66 
     67   // Strip trailing slashes.
     68   endp = path + strlen(path) - 1;
     69   while (endp > path && *endp == '/') {
     70     endp--;
     71   }
     72 
     73   // All slashes becomes "/".
     74   if (endp == path && *endp == '/') {
     75     startp = "/";
     76     len = 1;
     77     goto Exit;
     78   }
     79 
     80   // Find the start of the base.
     81   startp = endp;
     82   while (startp > path && *(startp - 1) != '/') {
     83     startp--;
     84   }
     85 
     86   len = endp - startp +1;
     87 
     88  Exit:
     89   result = len;
     90   if (buffer == NULL) {
     91     return result;
     92   }
     93   if (len > static_cast<int>(buffer_size) - 1) {
     94     len = buffer_size - 1;
     95     result = -1;
     96     errno = ERANGE;
     97   }
     98 
     99   if (len >= 0) {
    100     memcpy(buffer, startp, len);
    101     buffer[len] = 0;
    102   }
    103   return result;
    104 }
    105 
    106 int dirname_r(const char* path, char* buffer, size_t buffer_size) {
    107   const char* endp = NULL;
    108   int len;
    109   int result;
    110 
    111   // Empty or NULL string gets treated as ".".
    112   if (path == NULL || *path == '\0') {
    113     path = ".";
    114     len = 1;
    115     goto Exit;
    116   }
    117 
    118   // Strip trailing slashes.
    119   endp = path + strlen(path) - 1;
    120   while (endp > path && *endp == '/') {
    121     endp--;
    122   }
    123 
    124   // Find the start of the dir.
    125   while (endp > path && *endp != '/') {
    126     endp--;
    127   }
    128 
    129   // Either the dir is "/" or there are no slashes.
    130   if (endp == path) {
    131     path = (*endp == '/') ? "/" : ".";
    132     len = 1;
    133     goto Exit;
    134   }
    135 
    136   do {
    137     endp--;
    138   } while (endp > path && *endp == '/');
    139 
    140   len = endp - path + 1;
    141 
    142  Exit:
    143   result = len;
    144   if (len + 1 > MAXPATHLEN) {
    145     errno = ENAMETOOLONG;
    146     return -1;
    147   }
    148   if (buffer == NULL) {
    149     return result;
    150   }
    151 
    152   if (len > static_cast<int>(buffer_size) - 1) {
    153     len = buffer_size - 1;
    154     result = -1;
    155     errno = ERANGE;
    156   }
    157 
    158   if (len >= 0) {
    159     memcpy(buffer, path, len);
    160     buffer[len] = 0;
    161   }
    162   return result;
    163 }
    164