POSIX P1003.2/D11.2 compliance -- use mmap and make it simple

SCCS-vsn: usr.bin/cmp/cmp.c 5.5

diff --git a/usr/src/usr.bin/cmp/cmp.c b/usr/src/usr.bin/cmp/cmp.c
index 35c2e2d..bc6e093 100644 (file)
--- a/usr/src/usr.bin/cmp/cmp.c
+++ b/usr/src/usr.bin/cmp/cmp.c
@@ -12,10 +12,10 @@ char copyright[] =
 #endif /* not lint */
 
 #ifndef lint
 #endif /* not lint */
 
 #ifndef lint

-static char sccsid[] = "@(#)cmp.c      5.4 (Berkeley) %G%";
+static char sccsid[] = "@(#)cmp.c      5.5 (Berkeley) %G%";

 #endif /* not lint */
 
 #endif /* not lint */
 

-#include <sys/param.h>
+#include <sys/types.h>

 #include <sys/stat.h>
 #include <fcntl.h>
 #include <errno.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <errno.h>


@@ -23,38 +23,30 @@ static char sccsid[] = "@(#)cmp.c   5.4 (Berkeley) %G%";
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>

-#include <ctype.h>
+#include "extern.h"

 
 

-#define        EXITNODIFF      0
-#define        EXITDIFF        1
-#define        EXITERR         2
+int    lflag, sflag;

 
 

-int    all, fd1, fd2, silent;
-u_char buf1[MAXBSIZE], buf2[MAXBSIZE];
-char   *file1, *file2;
-
-void cmp __P((void));
-void endoffile __P((char *));
-void err __P((const char *fmt, ...));
-void ferr __P((char *));
-void skip __P((u_long, int, char *));
-void usage __P((void));
+static void usage __P((void));

 
 main(argc, argv)
        int argc;
        char *argv[];
 {
 
 main(argc, argv)
        int argc;
        char *argv[];
 {

-       int ch;
+       struct stat sb1, sb2;
+       off_t skip1, skip2;
+       int ch, fd1, fd2, special;
+       char *file1, *file2;

 
        while ((ch = getopt(argc, argv, "-ls")) != EOF)
                switch (ch) {
                case 'l':               /* print all differences */
 
        while ((ch = getopt(argc, argv, "-ls")) != EOF)
                switch (ch) {
                case 'l':               /* print all differences */

-                       all = 1;
+                       lflag = 1;

                        break;
                case 's':               /* silent run */
                        break;
                case 's':               /* silent run */

-                       silent = 1;
+                       sflag = 1;

                        break;
                        break;

-               case '-':               /* must be after any flags */
+               case '-':               /* stdin (must be after options) */

                        --optind;
                        goto endargs;
                case '?':
                        --optind;
                        goto endargs;
                case '?':


@@ -65,203 +57,59 @@ endargs:
        argv += optind;
        argc -= optind;
 
        argv += optind;
        argc -= optind;
 

+       if (lflag && sflag)
+               err("only one of -l and -s may be specified");
+

        if (argc < 2 || argc > 4)
                usage();
 
        if (argc < 2 || argc > 4)
                usage();
 

-       if (all && silent)
-               err("only one of -l and -s may be specified");
-       if (strcmp(file1 = argv[0], "-") == 0)
+       /* Backward compatibility -- handle "-" meaning stdin. */
+       special = 0;
+       if (strcmp(file1 = argv[0], "-") == 0) {
+               special = 1;

                fd1 = 0;
                fd1 = 0;

+               file1 = "stdin";
+       }

        else if ((fd1 = open(file1, O_RDONLY, 0)) < 0)
        else if ((fd1 = open(file1, O_RDONLY, 0)) < 0)

-               ferr(file1);
-       if (strcmp(file2 = argv[1], "-") == 0)
+               err("%s: %s", file1, strerror(errno));
+       if (strcmp(file2 = argv[1], "-") == 0) {
+               if (special)
+                       err("standard input may only be specified once");
+               special = 1;

                fd2 = 0;
                fd2 = 0;

-       else if ((fd2 = open(file2, O_RDONLY, 0)) < 0)
-               ferr(file2);
-       if (fd1 == fd2)
-               err("standard input may only be specified once");
-
-       /* handle skip arguments */
-       if (argc > 2) {
-               skip(strtol(argv[2], NULL, 10), fd1, file1);
-               if (argc == 4)
-                       skip(strtol(argv[3], NULL, 10), fd2, file2);
-       }
-       cmp();
-       /* NOTREACHED */
-}
-
-/*
- * skip --
- *     skip first part of file
- */
-void
-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)
-                               ferr(fname);
-                       else
-                               endoffile(fname);
-               }
+               file2 = "stdin";

        }
        }

-}
-
-void
-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:
-                       ferr(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:
-                                       ferr(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)
-                       ferr(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: byte %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;
+       else if ((fd2 = open(file2, O_RDONLY, 0)) < 0)
+               err("%s: %s", file2, strerror(errno));
+
+       skip1 = argc > 2 ? strtol(argv[2], NULL, 10) : 0;
+       skip2 = argc == 4 ? strtol(argv[3], NULL, 10) : 0;
+
+       if (!special) {
+               if (fstat(fd1, &sb1))
+                       err("%s: %s", file1, strerror(errno));
+               if (!S_ISREG(sb1.st_mode))
+                       special = 1;
+               else {
+                       if (fstat(fd2, &sb2))
+                               err("%s: %s", file2, strerror(errno));
+                       if (!S_ISREG(sb2.st_mode))
+                               special = 1;

                }
                }

-               /*
-                * 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);

        }
        }

-}
-
-/*
- * ferr --
- *     print file error message and die
- */
-void
-ferr(name)
-       char *name;
-{
-       if (!silent)
-               err("%s: %s", name, strerror(errno));
-       exit(EXITERR);
-}

 
 

-/*
- * endoffile --
- *     print end-of-file message and exit indicating the files were different
- */
-void
-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);
+       if (special)
+               c_special(fd1, file1, skip1, fd2, file2, skip2);
+       else
+               c_regular(fd1, file1, skip1, sb1.st_size,
+                   fd2, file2, skip2, sb2.st_size);
+       exit(0);

 }
 
 }
 

-/*
- * usage --
- *     print usage and die
- */
-void
+static void

 usage()
 {
        (void)fprintf(stderr,
            "usage: cmp [-ls] file1 file2 [skip1 [skip2]]\n");
 usage()
 {
        (void)fprintf(stderr,
            "usage: cmp [-ls] file1 file2 [skip1 [skip2]]\n");

-       exit(EXITERR);
-}
-
-#if __STDC__
-#include <stdarg.h>
-#else
-#include <varargs.h>
-#endif
-
-void
-#if __STDC__
-err(const char *fmt, ...)
-#else
-err(fmt, va_alist)
-       char *fmt;
-       va_dcl
-#endif
-{
-       va_list ap;
-#if __STDC__
-       va_start(ap, fmt);
-#else
-       va_start(ap);
-#endif
-       (void)fprintf(stderr, "cmp: ");
-       (void)vfprintf(stderr, fmt, ap);
-       va_end(ap);
-       (void)fprintf(stderr, "\n");
-       exit(EXITERR);
-       /* NOTREACHED */
+       exit(2);

 }
 }