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