328 lines
		
	
	
		
			8.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			328 lines
		
	
	
		
			8.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* treecmp - compare two trees		Author: Andy Tanenbaum */
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| 
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| /* This program recursively compares two trees and reports on differences.
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|  * It can be used, for example, when a project consists of a large number
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|  * of files and directories.  When a new release (i.e., a new tree) has been
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|  * prepared, the old and new tree can be compared to give a list of what has
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|  * changed.  The algorithm used is that the second tree is recursively
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|  * descended and for each file or directory found, the corresponding one in
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|  * the other tree checked.  The two arguments are not completely symmetric
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|  * because the second tree is descended, not the first one, but reversing
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|  * the arguments will still detect all the differences, only they will be
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|  * printed in a different order.  The program needs lots of stack space
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|  * because routines with local arrays are called recursively. The call is
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|  *    treecmp [-cv] old_dir new_dir
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|  * The -v flag (verbose) prints the directory names as they are processed.
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|  * The -c flag (changes) just prints the names of changed and new files.
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|  */
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| 
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| #include <sys/types.h>
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| #include <sys/stat.h>
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| #include <fcntl.h>
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| #include <string.h>
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| #include <unistd.h>
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| #include <stdlib.h>
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| #include <stdio.h>
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| 
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| #define BUFSIZE 4096		/* size of file buffers */
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| #define MAXPATH 128		/* longest acceptable path */
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| #define DIRENTLEN 14		/* number of characters in a file name */
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| 
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| struct dirstruct {		/* layout of a directory entry */
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|   ino_t inum;
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|   char fname[DIRENTLEN];
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| };
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| 
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| struct stat stat1, stat2;	/* stat buffers */
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| 
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| char buf1[BUFSIZE];		/* used for comparing bufs */
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| char buf2[BUFSIZE];		/* used for comparing bufs */
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| 
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| int changes;			/* set on -c flag */
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| int verbose;			/* set on -v flag */
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| 
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| _PROTOTYPE(int main, (int argc, char **argv));
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| _PROTOTYPE(void compare, (char *old, char *new));
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| _PROTOTYPE(void regular, (char *old, char *new));
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| _PROTOTYPE(void directory, (char *old, char *new));
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| _PROTOTYPE(void check, (char *s, struct dirstruct *dp1, int ent1, char *new));
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| _PROTOTYPE(void usage, (void));
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| 
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| int main(argc, argv)
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| int argc;
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| char *argv[];
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| {
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|   char *p;
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| 
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|   if (argc < 3 || argc > 4) usage();
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|   p = argv[1];
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|   if (argc == 4) {
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| 	if (*p != '-') usage();
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| 	p++;
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| 	if (*p == '\0') usage();
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| 	while (*p) {
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| 		if (*p == 'c') changes++;
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| 		if (*p == 'v') verbose++;
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| 		if (*p != 'c' && *p != 'v') usage();
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| 		p++;
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| 	}
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|   }
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|   if (argc == 3)
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| 	compare(argv[1], argv[2]);
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|   else
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| 	compare(argv[2], argv[3]);
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| 
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|   return(0);
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| }
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| 
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| void compare(old, new)
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| char *old, *new;
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| {
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| /* This is the main comparision routine.  It gets two path names as arguments
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|  * and stats them both.  Depending on the results, it calls other routines
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|  * to compare directories or files.
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|  */
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| 
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|   int type1, type2;
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| 
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|   if (stat(new, &stat1) < 0) {
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| 	/* The new file does not exist. */
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| 	if (changes == 0)
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| 		fprintf(stderr, "Cannot stat: %s\n", new);
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| 	else
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| 		printf("%s\n", new);
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| 	return;
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|   }
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|   if (stat(old, &stat2) < 0) {
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| 	/* The old file does not exist. */
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| 	if (changes == 0) 
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| 		fprintf(stderr, "Missing file: %s\n", old);
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| 	else
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| 		printf("%s\n", new);
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| 	return;
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|   }
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| 
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|   /* Examine the types of the files. */
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|   type1 = stat1.st_mode & S_IFMT;
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|   type2 = stat2.st_mode & S_IFMT;
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|   if (type1 != type2) {
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| 	fprintf(stderr, "Type diff: %s and %s\n", new, old);
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| 	return;
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|   }
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| 
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|   /* The types are the same. */
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|   switch (type1) {
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|       case S_IFREG:	regular(old, new);	break;
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|       case S_IFDIR:	directory(old, new);	break;
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|       case S_IFCHR:	break;
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|       case S_IFBLK:	break;
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|       default:		fprintf(stderr, "Unknown file type %o\n", type1);
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|   }
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|   return;
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| }
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| 
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| void regular(old, new)
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| char *old, *new;
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| {
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| /* Compare to regular files.  If they are different, complain. */
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| 
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|   int fd1, fd2, n1, n2;
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|   unsigned bytes;
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|   long count;
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| 
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|   if (stat1.st_size != stat2.st_size) {
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| 	if (changes == 0)
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| 		printf("Size diff: %s and %s\n", new, old);
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| 	else
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| 		printf("%s\n", new);
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| 	return;
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|   }
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| 
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|   /* The sizes are the same.  We actually have to read the files now. */
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|   fd1 = open(new, O_RDONLY);
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|   if (fd1 < 0) {
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| 	fprintf(stderr, "Cannot open %s for reading\n", new);
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| 	return;
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|   }
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|   fd2 = open(old, O_RDONLY);
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|   if (fd2 < 0) {
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| 	fprintf(stderr, "Cannot open %s for reading\n", old);
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| 	return;
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|   }
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|   count = stat1.st_size;
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|   while (count > 0L) {
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| 	bytes = (unsigned) (count > BUFSIZE ? BUFSIZE : count);	/* rd count */
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| 	n1 = read(fd1, buf1, bytes);
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| 	n2 = read(fd2, buf2, bytes);
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| 	if (n1 != n2) {
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| 		if (changes == 0)
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| 			printf("Length diff: %s and %s\n", new, old);
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| 		else
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| 			printf("%s\n", new);
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| 		close(fd1);
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| 		close(fd2);
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| 		return;
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| 	}
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| 
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| 	/* Compare the buffers. */
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| 	if (memcmp((void *) buf1, (void *) buf2, (size_t) n1) != 0) {
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| 		if (changes == 0)
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| 			printf("File diff: %s and %s\n", new, old);
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| 		else
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| 			printf("%s\n", new);
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| 		close(fd1);
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| 		close(fd2);
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| 		return;
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| 	}
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| 	count -= n1;
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|   }
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|   close(fd1);
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|   close(fd2);
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| }
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| 
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| void directory(old, new)
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| char *old, *new;
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| {
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| /* Recursively compare two directories by reading them and comparing their
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|  * contents.  The order of the entries need not be the same.
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|  */
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| 
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|   int fd1, fd2, n1, n2, ent1, ent2, i, used1 = 0, used2 = 0;
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|   char *dir1buf, *dir2buf;
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|   char name1buf[MAXPATH], name2buf[MAXPATH];
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|   struct dirstruct *dp1, *dp2;
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|   unsigned dir1bytes, dir2bytes;
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| 
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|   /* Allocate space to read in the directories */
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|   dir1bytes = (unsigned) stat1.st_size;
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|   dir1buf = (char *)malloc((size_t)dir1bytes);
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|   if (dir1buf == 0) {
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| 	fprintf(stderr, "Cannot process directory %s: out of memory\n", new);
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| 	return;
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|   }
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|   dir2bytes = (unsigned) stat2.st_size;
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|   dir2buf = (char *)malloc((size_t)dir2bytes);
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|   if (dir2buf == 0) {
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| 	fprintf(stderr, "Cannot process directory %s: out of memory\n", old);
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| 	free(dir1buf);
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| 	return;
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|   }
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| 
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|   /* Read in the directories. */
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|   fd1 = open(new, O_RDONLY);
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|   if (fd1 > 0) n1 = read(fd1, dir1buf, dir1bytes);
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|   if (fd1 < 0 || n1 != dir1bytes) {
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| 	fprintf(stderr, "Cannot read directory %s\n", new);
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| 	free(dir1buf);
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| 	free(dir2buf);
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| 	if (fd1 > 0) close(fd1);
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| 	return;
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|   }
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|   close(fd1);
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| 
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|   fd2 = open(old, O_RDONLY);
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|   if (fd2 > 0) n2 = read(fd2, dir2buf, dir2bytes);
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|   if (fd2 < 0 || n2 != dir2bytes) {
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| 	fprintf(stderr, "Cannot read directory %s\n", old);
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| 	free(dir1buf);
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| 	free(dir2buf);
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| 	close(fd1);
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| 	if (fd2 > 0) close(fd2);
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| 	return;
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|   }
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|   close(fd2);
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| 
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|   /* Linearly search directories */
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|   ent1 = dir1bytes / sizeof(struct dirstruct);
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|   dp1 = (struct dirstruct *) dir1buf;
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|   for (i = 0; i < ent1; i++) {
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| 	if (dp1->inum != 0) used1++;
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| 	dp1++;
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|   }
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| 
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|   ent2 = dir2bytes / sizeof(struct dirstruct);
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|   dp2 = (struct dirstruct *) dir2buf;
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|   for (i = 0; i < ent2; i++) {
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| 	if (dp2->inum != 0) used2++;
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| 	dp2++;
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|   }
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| 
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|   if (verbose) printf("Directory %s: %d entries\n", new, used1);
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| 
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|   /* Check to see if any entries in dir2 are missing from dir1. */
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|   dp1 = (struct dirstruct *) dir1buf;
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|   dp2 = (struct dirstruct *) dir2buf;
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|   for (i = 0; i < ent2; i++) {
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| 	if (dp2->inum == 0 || strcmp(dp2->fname, ".") == 0 ||
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| 					    strcmp(dp2->fname, "..") == 0) {
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| 		dp2++;
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| 		continue;
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| 	}
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| 	check(dp2->fname, dp1, ent1, new);
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| 	dp2++;
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|   }
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| 
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|   /* Recursively process all the entries in dir1. */
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|   dp1 = (struct dirstruct *) dir1buf;
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|   for (i = 0; i < ent1; i++) {
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| 	if (dp1->inum == 0 || strcmp(dp1->fname, ".") == 0 ||
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| 	    strcmp(dp1->fname, "..") == 0) {
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| 		dp1++;
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| 		continue;
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| 	}
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| 	if (strlen(new) + DIRENTLEN >= MAXPATH) {
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| 		fprintf(stderr, "Path too long: %s\n", new);
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| 		free(dir1buf);
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| 		free(dir2buf);
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| 		return;
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| 	}
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| 	if (strlen(old) + DIRENTLEN >= MAXPATH) {
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| 		fprintf(stderr, "Path too long: %s\n", old);
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| 		free(dir1buf);
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| 		free(dir2buf);
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| 		return;
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| 	}
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| 	strcpy(name1buf, old);
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| 	strcat(name1buf, "/");
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| 	strncat(name1buf, dp1->fname, (size_t)DIRENTLEN);
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| 	strcpy(name2buf, new);
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| 	strcat(name2buf, "/");
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| 	strncat(name2buf, dp1->fname, (size_t)DIRENTLEN);
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| 
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| 	/* Here is the recursive call to process an entry. */
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| 	compare(name1buf, name2buf);	/* recursive call */
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| 	dp1++;
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|   }
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| 
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|   free(dir1buf);
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|   free(dir2buf);
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| }
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| 
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| void check(s, dp1, ent1, new)
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| char *s;
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| struct dirstruct *dp1;
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| int ent1;
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| char *new;
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| {
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| /* See if the file name 's' is present in the directory 'dirbuf'. */
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|   int i;
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|   char file[DIRENTLEN+1];
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| 
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|   for (i = 0; i < ent1; i++) {
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| 	if (strncmp(dp1->fname, s, (size_t)DIRENTLEN) == 0) return;
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| 	dp1++;
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|   }
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|   if (changes == 0) {
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| 	strncpy(file, s, DIRENTLEN);
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| 	file[DIRENTLEN] = '\0';
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| 	printf("Missing file: %s/%s\n", new, file);
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|   }
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| 	
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| }
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| 
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| void usage()
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| {
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|   printf("Usage: treecmp [-cv] old_dir new_dir\n");
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|   exit(1);
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| }
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