+/*
+ * Copyright (c) 1987 Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef lint
+char copyright[] =
+"@(#) Copyright (c) 1987, 1990 Regents of the University of California.\n\
+ All rights reserved.\n";
+#endif /* not lint */
+
+#ifndef lint
+static char sccsid[] = "@(#)cmp.c 5.3 (Berkeley) 6/1/90";
+#endif /* not lint */
+
+#include <sys/param.h>
+#include <sys/file.h>
+#include <sys/stat.h>
+#include <stdio.h>
+#include <ctype.h>
+#include <errno.h>
+
+#define EXITNODIFF 0
+#define EXITDIFF 1
+#define EXITERR 2
+
+int all, fd1, fd2, silent;
+u_char buf1[MAXBSIZE], buf2[MAXBSIZE];
+char *file1, *file2;
+
+main(argc, argv)
+ int argc;
+ char *argv[];
+{
+ extern char *optarg;
+ extern int optind;
+ int ch;
+ u_long otoi();
+
+ while ((ch = getopt(argc, argv, "-ls")) != EOF)
+ switch (ch) {
+ case 'l': /* print all differences */
+ all = 1;
+ break;
+ case 's': /* silent run */
+ silent = 1;
+ break;
+ case '-': /* must be after any flags */
+ --optind;
+ goto endargs;
+ case '?':
+ default:
+ usage();
+ }
+endargs:
+ argv += optind;
+ argc -= optind;
+
+ if (argc < 2 || argc > 4)
+ usage();
+
+ if (all && silent) {
+ fprintf(stderr,
+ "cmp: only one of -l and -s may be specified.\n");
+ exit(EXITERR);
+ }
+ if (strcmp(file1 = argv[0], "-") == 0)
+ fd1 = 0;
+ else if ((fd1 = open(file1, O_RDONLY, 0)) < 0)
+ error(file1);
+ if (strcmp(file2 = argv[1], "-") == 0)
+ fd2 = 0;
+ else if ((fd2 = open(file2, O_RDONLY, 0)) < 0)
+ error(file2);
+ if (fd1 == fd2) {
+ fprintf(stderr,
+ "cmp: standard input may only be specified once.\n");
+ exit(EXITERR);
+ }
+
+ /* handle skip arguments */
+ if (argc > 2) {
+ skip(otoi(argv[2]), fd1, file1);
+ if (argc == 4)
+ skip(otoi(argv[3]), fd2, file2);
+ }
+ cmp();
+ /*NOTREACHED*/
+}
+
+/*
+ * skip --
+ * skip first part of file
+ */
+skip(dist, fd, fname)
+ register u_long dist;
+ register int fd;
+ char *fname;
+{
+ register int rlen, nread;
+
+ for (; dist; dist -= rlen) {
+ rlen = MIN(dist, sizeof(buf1));
+ if ((nread = read(fd, buf1, rlen)) != rlen) {
+ if (nread < 0)
+ error(fname);
+ else
+ endoffile(fname);
+ }
+ }
+}
+
+cmp()
+{
+ register u_char *p1, *p2;
+ register int cnt, len1, len2;
+ register long byte, line;
+ int dfound = 0;
+
+ for (byte = 0, line = 1; ; ) {
+ switch (len1 = read(fd1, buf1, MAXBSIZE)) {
+ case -1:
+ error(file1);
+ case 0:
+ /*
+ * read of file 1 just failed, find out
+ * if there's anything left in file 2
+ */
+ switch (read(fd2, buf2, 1)) {
+ case -1:
+ error(file2);
+ /* NOTREACHED */
+ case 0:
+ exit(dfound ? EXITDIFF : EXITNODIFF);
+ /* NOTREACHED */
+ default:
+ endoffile(file1);
+ break;
+ }
+ }
+ /*
+ * file1 might be stdio, which means that a read of less than
+ * MAXBSIZE might not mean an EOF. So, read whatever we read
+ * from file1 from file2.
+ */
+ if ((len2 = read(fd2, buf2, len1)) == -1)
+ error(file2);
+ if (bcmp(buf1, buf2, len2)) {
+ if (silent)
+ exit(EXITDIFF);
+ if (all) {
+ dfound = 1;
+ for (p1 = buf1, p2 = buf2, cnt = len2; cnt--;
+ ++p1, ++p2) {
+ ++byte;
+ if (*p1 != *p2)
+ printf("%6ld %3o %3o\n",
+ byte, *p1, *p2);
+ }
+ } else for (p1 = buf1, p2 = buf2; ; ++p1, ++p2) {
+ ++byte;
+ if (*p1 != *p2) {
+ printf("%s %s differ: char %ld, line %ld\n", file1, file2, byte, line);
+ exit(EXITDIFF);
+ }
+ if (*p1 == '\n')
+ ++line;
+ }
+ } else {
+ byte += len2;
+ /*
+ * here's the real performance problem, we've got to
+ * count the stupid lines, which means that -l is a
+ * *much* faster version, i.e., unless you really
+ * *want* to know the line number, run -s or -l.
+ */
+ if (!silent && !all)
+ for (p1 = buf1, cnt = len2; cnt--; )
+ if (*p1++ == '\n')
+ ++line;
+ }
+ /*
+ * couldn't read as much from file2 as from file1; checked
+ * here because there might be a difference before we got
+ * to this point, which would have precedence.
+ */
+ if (len2 < len1)
+ endoffile(file2);
+ }
+}
+
+/*
+ * otoi --
+ * octal/decimal string to u_long
+ */
+u_long
+otoi(s)
+ register char *s;
+{
+ register u_long val;
+ register int base;
+
+ base = (*s == '0') ? 8 : 10;
+ for (val = 0; isdigit(*s); ++s)
+ val = val * base + *s - '0';
+ return (val);
+}
+
+/*
+ * error --
+ * print I/O error message and die
+ */
+error(filename)
+ char *filename;
+{
+ extern int errno;
+ char *strerror();
+
+ if (!silent)
+ (void) fprintf(stderr, "cmp: %s: %s\n",
+ filename, strerror(errno));
+ exit(EXITERR);
+}
+
+/*
+ * endoffile --
+ * print end-of-file message and exit indicating the files were different
+ */
+endoffile(filename)
+ char *filename;
+{
+ /* 32V put this message on stdout, S5 does it on stderr. */
+ /* POSIX.2 currently does it on stdout-- Hooray! */
+ if (!silent)
+ (void) printf("cmp: EOF on %s\n", filename);
+ exit(EXITDIFF);
+}
+
+/*
+ * usage --
+ * print usage and die
+ */
+usage()
+{
+ fputs("usage: cmp [-ls] file1 file2 [skip1] [skip2]\n", stderr);
+ exit(EXITERR);
+}
projects / unix-history / commitdiff