1/* $NetBSD: dir.c,v 1.1.1.1 2016/01/13 03:15:30 christos Exp $ */ 2 3/* Read, sort and compare two directories. Used for GNU DIFF. 4 5 Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1998, 2001, 2002 6 Free Software Foundation, Inc. 7 8 This file is part of GNU DIFF. 9 10 GNU DIFF is free software; you can redistribute it and/or modify 11 it under the terms of the GNU General Public License as published by 12 the Free Software Foundation; either version 2, or (at your option) 13 any later version. 14 15 GNU DIFF is distributed in the hope that it will be useful, 16 but WITHOUT ANY WARRANTY; without even the implied warranty of 17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 GNU General Public License for more details. 19 20 You should have received a copy of the GNU General Public License 21 along with this program; see the file COPYING. 22 If not, write to the Free Software Foundation, 23 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ 24 25#include "diff.h" 26#include <error.h> 27#include <exclude.h> 28#include <setjmp.h> 29#include <xalloc.h> 30 31/* Read the directory named by DIR and store into DIRDATA a sorted vector 32 of filenames for its contents. DIR->desc == -1 means this directory is 33 known to be nonexistent, so set DIRDATA to an empty vector. 34 Return -1 (setting errno) if error, 0 otherwise. */ 35 36struct dirdata 37{ 38 size_t nnames; /* Number of names. */ 39 char const **names; /* Sorted names of files in dir, followed by 0. */ 40 char *data; /* Allocated storage for file names. */ 41}; 42 43/* Whether file names in directories should be compared with strcoll. */ 44static bool locale_specific_sorting; 45 46/* Where to go if strcoll fails. */ 47static jmp_buf failed_strcoll; 48 49static bool dir_loop (struct comparison const *, int); 50static int compare_names_for_qsort (void const *, void const *); 51 52 53/* Read a directory and get its vector of names. */ 54 55static bool 56dir_read (struct file_data const *dir, struct dirdata *dirdata) 57{ 58 register struct dirent *next; 59 register size_t i; 60 61 /* Address of block containing the files that are described. */ 62 char const **names; 63 64 /* Number of files in directory. */ 65 size_t nnames; 66 67 /* Allocated and used storage for file name data. */ 68 char *data; 69 size_t data_alloc, data_used; 70 71 dirdata->names = 0; 72 dirdata->data = 0; 73 nnames = 0; 74 data = 0; 75 76 if (dir->desc != -1) 77 { 78 /* Open the directory and check for errors. */ 79 register DIR *reading = opendir (dir->name); 80 if (!reading) 81 return 0; 82 83 /* Initialize the table of filenames. */ 84 85 data_alloc = 512; 86 data_used = 0; 87 dirdata->data = data = xmalloc (data_alloc); 88 89 /* Read the directory entries, and insert the subfiles 90 into the `data' table. */ 91 92 while ((errno = 0, (next = readdir (reading)) != 0)) 93 { 94 char *d_name = next->d_name; 95 size_t d_size = NAMLEN (next) + 1; 96 97 /* Ignore "." and "..". */ 98 if (d_name[0] == '.' 99 && (d_name[1] == 0 || (d_name[1] == '.' && d_name[2] == 0))) 100 continue; 101 102 if (excluded_filename (excluded, d_name)) 103 continue; 104 105 while (data_alloc < data_used + d_size) 106 { 107 if (PTRDIFF_MAX / 2 <= data_alloc) 108 xalloc_die (); 109 dirdata->data = data = xrealloc (data, data_alloc *= 2); 110 } 111 112 memcpy (data + data_used, d_name, d_size); 113 data_used += d_size; 114 nnames++; 115 } 116 if (errno) 117 { 118 int e = errno; 119 closedir (reading); 120 errno = e; 121 return 0; 122 } 123#if CLOSEDIR_VOID 124 closedir (reading); 125#else 126 if (closedir (reading) != 0) 127 return 0; 128#endif 129 } 130 131 /* Create the `names' table from the `data' table. */ 132 if (PTRDIFF_MAX / sizeof *names - 1 <= nnames) 133 xalloc_die (); 134 dirdata->names = names = xmalloc ((nnames + 1) * sizeof *names); 135 dirdata->nnames = nnames; 136 for (i = 0; i < nnames; i++) 137 { 138 names[i] = data; 139 data += strlen (data) + 1; 140 } 141 names[nnames] = 0; 142 return 1; 143} 144 145/* Compare file names, returning a value compatible with strcmp. */ 146 147static int 148compare_names (char const *name1, char const *name2) 149{ 150 if (ignore_file_name_case) 151 { 152 int r = strcasecmp (name1, name2); 153 if (r) 154 return r; 155 } 156 157 if (locale_specific_sorting) 158 { 159 int r; 160 errno = 0; 161 r = strcoll (name1, name2); 162 if (errno) 163 { 164 error (0, errno, _("cannot compare file names `%s' and `%s'"), 165 name1, name2); 166 longjmp (failed_strcoll, 1); 167 } 168 if (r) 169 return r; 170 } 171 172 return file_name_cmp (name1, name2); 173} 174 175/* A wrapper for compare_names suitable as an argument for qsort. */ 176 177static int 178compare_names_for_qsort (void const *file1, void const *file2) 179{ 180 char const *const *f1 = file1; 181 char const *const *f2 = file2; 182 return compare_names (*f1, *f2); 183} 184 185/* Compare the contents of two directories named in CMP. 186 This is a top-level routine; it does everything necessary for diff 187 on two directories. 188 189 CMP->file[0].desc == -1 says directory CMP->file[0] doesn't exist, 190 but pretend it is empty. Likewise for CMP->file[1]. 191 192 HANDLE_FILE is a caller-provided subroutine called to handle each file. 193 It gets three operands: CMP, name of file in dir 0, name of file in dir 1. 194 These names are relative to the original working directory. 195 196 For a file that appears in only one of the dirs, one of the name-args 197 to HANDLE_FILE is zero. 198 199 Returns the maximum of all the values returned by HANDLE_FILE, 200 or EXIT_TROUBLE if trouble is encountered in opening files. */ 201 202int 203diff_dirs (struct comparison const *cmp, 204 int (*handle_file) (struct comparison const *, 205 char const *, char const *)) 206{ 207 struct dirdata dirdata[2]; 208 int volatile val = EXIT_SUCCESS; 209 int i; 210 211 if ((cmp->file[0].desc == -1 || dir_loop (cmp, 0)) 212 && (cmp->file[1].desc == -1 || dir_loop (cmp, 1))) 213 { 214 error (0, 0, "%s: recursive directory loop", 215 cmp->file[cmp->file[0].desc == -1].name); 216 return EXIT_TROUBLE; 217 } 218 219 /* Get contents of both dirs. */ 220 for (i = 0; i < 2; i++) 221 if (! dir_read (&cmp->file[i], &dirdata[i])) 222 { 223 perror_with_name (cmp->file[i].name); 224 val = EXIT_TROUBLE; 225 } 226 227 if (val == EXIT_SUCCESS) 228 { 229 char const **volatile names[2]; 230 names[0] = dirdata[0].names; 231 names[1] = dirdata[1].names; 232 233 /* Use locale-specific sorting if possible, else native byte order. */ 234 locale_specific_sorting = 1; 235 if (setjmp (failed_strcoll)) 236 locale_specific_sorting = 0; 237 238 /* Sort the directories. */ 239 for (i = 0; i < 2; i++) 240 qsort (names[i], dirdata[i].nnames, sizeof *dirdata[i].names, 241 compare_names_for_qsort); 242 243 /* If `-S name' was given, and this is the topmost level of comparison, 244 ignore all file names less than the specified starting name. */ 245 246 if (starting_file && ! cmp->parent) 247 { 248 while (*names[0] && compare_names (*names[0], starting_file) < 0) 249 names[0]++; 250 while (*names[1] && compare_names (*names[1], starting_file) < 0) 251 names[1]++; 252 } 253 254 /* Loop while files remain in one or both dirs. */ 255 while (*names[0] || *names[1]) 256 { 257 /* Compare next name in dir 0 with next name in dir 1. 258 At the end of a dir, 259 pretend the "next name" in that dir is very large. */ 260 int nameorder = (!*names[0] ? 1 : !*names[1] ? -1 261 : compare_names (*names[0], *names[1])); 262 int v1 = (*handle_file) (cmp, 263 0 < nameorder ? 0 : *names[0]++, 264 nameorder < 0 ? 0 : *names[1]++); 265 if (val < v1) 266 val = v1; 267 } 268 } 269 270 for (i = 0; i < 2; i++) 271 { 272 if (dirdata[i].names) 273 free (dirdata[i].names); 274 if (dirdata[i].data) 275 free (dirdata[i].data); 276 } 277 278 return val; 279} 280 281/* Return nonzero if CMP is looping recursively in argument I. */ 282 283static bool 284dir_loop (struct comparison const *cmp, int i) 285{ 286 struct comparison const *p = cmp; 287 while ((p = p->parent)) 288 if (0 < same_file (&p->file[i].stat, &cmp->file[i].stat)) 289 return 1; 290 return 0; 291} 292