1 /* 2 * Copyright (c) 1987 Regents of the University of California. 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 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE. 32 */ 33 34 #ifndef lint 35 char copyright[] = 36 "@(#) Copyright (c) 1987, 1990 Regents of the University of California.\n\ 37 All rights reserved.\n"; 38 #endif /* not lint */ 39 40 #ifndef lint 41 /*static char sccsid[] = "from: @(#)cmp.c 5.3 (Berkeley) 6/1/90";*/ 42 static char rcsid[] = "$Id: cmp.c,v 1.4 1993/11/23 00:50:46 jtc Exp $"; 43 #endif /* not lint */ 44 45 #include <sys/param.h> 46 #include <sys/file.h> 47 #include <sys/stat.h> 48 #include <stdio.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <ctype.h> 52 #include <errno.h> 53 #include <locale.h> 54 #include <unistd.h> 55 56 #define EXITNODIFF 0 57 #define EXITDIFF 1 58 #define EXITERR 2 59 60 void skip __P(()); 61 __dead void cmp __P(()); 62 __dead void error __P(()); 63 __dead void endoffile __P(()); 64 __dead void usage __P(()); 65 66 int all, fd1, fd2, silent; 67 u_char buf1[MAXBSIZE], buf2[MAXBSIZE]; 68 char *file1, *file2; 69 70 int 71 main(argc, argv) 72 int argc; 73 char **argv; 74 { 75 int ch; 76 77 setlocale(LC_ALL, ""); 78 79 while ((ch = getopt(argc, argv, "ls")) != -1) 80 switch (ch) { 81 case 'l': /* print all differences */ 82 all = 1; 83 break; 84 case 's': /* silent run */ 85 silent = 1; 86 break; 87 case '?': 88 default: 89 usage(); 90 } 91 argv += optind; 92 argc -= optind; 93 94 if (argc < 2 || argc > 4) 95 usage(); 96 97 if (all && silent) 98 usage (); 99 100 if (strcmp(file1 = argv[0], "-") == 0) 101 fd1 = 0; 102 else if ((fd1 = open(file1, O_RDONLY, 0)) < 0) 103 error(file1); 104 if (strcmp(file2 = argv[1], "-") == 0) 105 fd2 = 0; 106 else if ((fd2 = open(file2, O_RDONLY, 0)) < 0) 107 error(file2); 108 if (fd1 == fd2) { 109 fprintf(stderr, 110 "cmp: standard input may only be specified once.\n"); 111 exit(EXITERR); 112 } 113 114 /* handle skip arguments */ 115 if (argc > 2) { 116 skip(strtoul(argv[2], NULL, 0), fd1, file1); 117 if (argc == 4) 118 skip(strtoul(argv[3], NULL, 0), fd2, file2); 119 } 120 cmp(); 121 /*NOTREACHED*/ 122 } 123 124 /* 125 * skip -- 126 * skip first part of file 127 */ 128 void 129 skip(dist, fd, fname) 130 register u_long dist; 131 register int fd; 132 char *fname; 133 { 134 register int rlen, nread; 135 136 for (; dist; dist -= rlen) { 137 rlen = MIN(dist, sizeof(buf1)); 138 if ((nread = read(fd, buf1, rlen)) != rlen) { 139 if (nread < 0) 140 error(fname); 141 else 142 endoffile(fname); 143 } 144 } 145 } 146 147 void 148 cmp() 149 { 150 register u_char *p1, *p2; 151 register int cnt, len1, len2; 152 register long byte, line; 153 int dfound = 0; 154 155 for (byte = 0, line = 1; ; ) { 156 switch (len1 = read(fd1, buf1, MAXBSIZE)) { 157 case -1: 158 error(file1); 159 case 0: 160 /* 161 * read of file 1 just failed, find out 162 * if there's anything left in file 2 163 */ 164 switch (read(fd2, buf2, 1)) { 165 case -1: 166 error(file2); 167 /* NOTREACHED */ 168 case 0: 169 exit(dfound ? EXITDIFF : EXITNODIFF); 170 /* NOTREACHED */ 171 default: 172 endoffile(file1); 173 break; 174 } 175 } 176 /* 177 * file1 might be stdio, which means that a read of less than 178 * MAXBSIZE might not mean an EOF. So, read whatever we read 179 * from file1 from file2. 180 */ 181 if ((len2 = read(fd2, buf2, len1)) == -1) 182 error(file2); 183 if (memcmp(buf1, buf2, len2)) { 184 if (silent) 185 exit(EXITDIFF); 186 if (all) { 187 dfound = 1; 188 for (p1 = buf1, p2 = buf2, cnt = len2; cnt--; 189 ++p1, ++p2) { 190 ++byte; 191 if (*p1 != *p2) 192 printf("%6ld %3o %3o\n", 193 byte, *p1, *p2); 194 } 195 } else for (p1 = buf1, p2 = buf2; ; ++p1, ++p2) { 196 ++byte; 197 if (*p1 != *p2) { 198 printf("%s %s differ: char %ld, line %ld\n", file1, file2, byte, line); 199 exit(EXITDIFF); 200 } 201 if (*p1 == '\n') 202 ++line; 203 } 204 } else { 205 byte += len2; 206 /* 207 * here's the real performance problem, we've got to 208 * count the stupid lines, which means that -l is a 209 * *much* faster version, i.e., unless you really 210 * *want* to know the line number, run -s or -l. 211 */ 212 if (!silent && !all) 213 for (p1 = buf1, cnt = len2; cnt--; ) 214 if (*p1++ == '\n') 215 ++line; 216 } 217 /* 218 * couldn't read as much from file2 as from file1; checked 219 * here because there might be a difference before we got 220 * to this point, which would have precedence. 221 */ 222 if (len2 < len1) 223 endoffile(file2); 224 } 225 } 226 227 /* 228 * error -- 229 * print I/O error message and die 230 */ 231 void 232 error(filename) 233 char *filename; 234 { 235 extern int errno; 236 char *strerror(); 237 238 if (!silent) 239 (void) fprintf(stderr, "cmp: %s: %s\n", 240 filename, strerror(errno)); 241 exit(EXITERR); 242 } 243 244 /* 245 * endoffile -- 246 * print end-of-file message and exit indicating the files were different 247 */ 248 void 249 endoffile(filename) 250 char *filename; 251 { 252 if (!silent) 253 (void) fprintf(stderr, "cmp: EOF on %s\n", filename); 254 exit(EXITDIFF); 255 } 256 257 /* 258 * usage -- 259 * print usage and die 260 */ 261 void 262 usage() 263 { 264 fputs("usage: cmp [-l | -s] file1 file2 [skip1] [skip2]\n", stderr); 265 exit(EXITERR); 266 } 267