1 /* Read, sort and compare two directories. Used for GNU DIFF. 2 3 Copyright (C) 1988, 1989, 1992, 1993, 1994, 1995, 1998, 2001, 2002, 4 2004 Free Software Foundation, Inc. 5 6 This file is part of GNU DIFF. 7 8 GNU DIFF is free software; you can redistribute it and/or modify 9 it under the terms of the GNU General Public License as published by 10 the Free Software Foundation; either version 2, or (at your option) 11 any later version. 12 13 GNU DIFF is distributed in the hope that it will be useful, 14 but WITHOUT ANY WARRANTY; without even the implied warranty of 15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16 GNU General Public License for more details. 17 18 You should have received a copy of the GNU General Public License 19 along with this program; see the file COPYING. 20 If not, write to the Free Software Foundation, 21 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ 22 23 #include "diff.h" 24 #include <error.h> 25 #include <exclude.h> 26 #include <setjmp.h> 27 #include <strcase.h> 28 #include <xalloc.h> 29 30 /* Read the directory named by DIR and store into DIRDATA a sorted vector 31 of filenames for its contents. DIR->desc == -1 means this directory is 32 known to be nonexistent, so set DIRDATA to an empty vector. 33 Return -1 (setting errno) if error, 0 otherwise. */ 34 35 struct dirdata 36 { 37 size_t nnames; /* Number of names. */ 38 char const **names; /* Sorted names of files in dir, followed by 0. */ 39 char *data; /* Allocated storage for file names. */ 40 }; 41 42 /* Whether file names in directories should be compared with 43 locale-specific sorting. */ 44 static bool locale_specific_sorting; 45 46 /* Where to go if locale-specific sorting fails. */ 47 static jmp_buf failed_locale_specific_sorting; 48 49 static bool dir_loop (struct comparison const *, int); 50 static int compare_names_for_qsort (void const *, void const *); 51 52 53 /* Read a directory and get its vector of names. */ 54 55 static bool 56 dir_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 false; 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 false; 122 } 123 #if CLOSEDIR_VOID 124 closedir (reading); 125 #else 126 if (closedir (reading) != 0) 127 return false; 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 true; 143 } 144 145 /* Compare file names, returning a value compatible with strcmp. */ 146 147 static int 148 compare_names (char const *name1, char const *name2) 149 { 150 if (locale_specific_sorting) 151 { 152 int r; 153 errno = 0; 154 if (ignore_file_name_case) 155 r = strcasecoll (name1, name2); 156 else 157 r = strcoll (name1, name2); 158 if (errno) 159 { 160 error (0, errno, _("cannot compare file names `%s' and `%s'"), 161 name1, name2); 162 longjmp (failed_locale_specific_sorting, 1); 163 } 164 return r; 165 } 166 167 return (ignore_file_name_case 168 ? strcasecmp (name1, name2) 169 : file_name_cmp (name1, name2)); 170 } 171 172 /* A wrapper for compare_names suitable as an argument for qsort. */ 173 174 static int 175 compare_names_for_qsort (void const *file1, void const *file2) 176 { 177 char const *const *f1 = file1; 178 char const *const *f2 = file2; 179 return compare_names (*f1, *f2); 180 } 181 182 /* Compare the contents of two directories named in CMP. 183 This is a top-level routine; it does everything necessary for diff 184 on two directories. 185 186 CMP->file[0].desc == -1 says directory CMP->file[0] doesn't exist, 187 but pretend it is empty. Likewise for CMP->file[1]. 188 189 HANDLE_FILE is a caller-provided subroutine called to handle each file. 190 It gets three operands: CMP, name of file in dir 0, name of file in dir 1. 191 These names are relative to the original working directory. 192 193 For a file that appears in only one of the dirs, one of the name-args 194 to HANDLE_FILE is zero. 195 196 Returns the maximum of all the values returned by HANDLE_FILE, 197 or EXIT_TROUBLE if trouble is encountered in opening files. */ 198 199 int 200 diff_dirs (struct comparison const *cmp, 201 int (*handle_file) (struct comparison const *, 202 char const *, char const *)) 203 { 204 struct dirdata dirdata[2]; 205 int volatile val = EXIT_SUCCESS; 206 int i; 207 208 if ((cmp->file[0].desc == -1 || dir_loop (cmp, 0)) 209 && (cmp->file[1].desc == -1 || dir_loop (cmp, 1))) 210 { 211 error (0, 0, "%s: recursive directory loop", 212 cmp->file[cmp->file[0].desc == -1].name); 213 return EXIT_TROUBLE; 214 } 215 216 /* Get contents of both dirs. */ 217 for (i = 0; i < 2; i++) 218 if (! dir_read (&cmp->file[i], &dirdata[i])) 219 { 220 perror_with_name (cmp->file[i].name); 221 val = EXIT_TROUBLE; 222 } 223 224 if (val == EXIT_SUCCESS) 225 { 226 char const **volatile names[2]; 227 names[0] = dirdata[0].names; 228 names[1] = dirdata[1].names; 229 230 /* Use locale-specific sorting if possible, else native byte order. */ 231 locale_specific_sorting = true; 232 if (setjmp (failed_locale_specific_sorting)) 233 locale_specific_sorting = false; 234 235 /* Sort the directories. */ 236 for (i = 0; i < 2; i++) 237 qsort (names[i], dirdata[i].nnames, sizeof *dirdata[i].names, 238 compare_names_for_qsort); 239 240 /* If `-S name' was given, and this is the topmost level of comparison, 241 ignore all file names less than the specified starting name. */ 242 243 if (starting_file && ! cmp->parent) 244 { 245 while (*names[0] && compare_names (*names[0], starting_file) < 0) 246 names[0]++; 247 while (*names[1] && compare_names (*names[1], starting_file) < 0) 248 names[1]++; 249 } 250 251 /* Loop while files remain in one or both dirs. */ 252 while (*names[0] || *names[1]) 253 { 254 /* Compare next name in dir 0 with next name in dir 1. 255 At the end of a dir, 256 pretend the "next name" in that dir is very large. */ 257 int nameorder = (!*names[0] ? 1 : !*names[1] ? -1 258 : compare_names (*names[0], *names[1])); 259 int v1 = (*handle_file) (cmp, 260 0 < nameorder ? 0 : *names[0]++, 261 nameorder < 0 ? 0 : *names[1]++); 262 if (val < v1) 263 val = v1; 264 } 265 } 266 267 for (i = 0; i < 2; i++) 268 { 269 if (dirdata[i].names) 270 free (dirdata[i].names); 271 if (dirdata[i].data) 272 free (dirdata[i].data); 273 } 274 275 return val; 276 } 277 278 /* Return nonzero if CMP is looping recursively in argument I. */ 279 280 static bool 281 dir_loop (struct comparison const *cmp, int i) 282 { 283 struct comparison const *p = cmp; 284 while ((p = p->parent)) 285 if (0 < same_file (&p->file[i].stat, &cmp->file[i].stat)) 286 return true; 287 return false; 288 } 289