last nail into error_msg() (de)capitalization
[oweals/busybox.git] / libbb / copy_file.c
index d2794e7d646e985e2821143457a374515ec51222..0135831fe0a35536ddfc090f74e18f36dd0c9cf1 100644 (file)
 
 #include "libbb.h"
 
+static int retry_overwrite(const char *dest, int flags)
+{
+       if (!(flags & (FILEUTILS_FORCE|FILEUTILS_INTERACTIVE))) {
+               fprintf(stderr, "'%s' exists\n", dest);
+               return -1;
+       }
+       if (flags & FILEUTILS_INTERACTIVE) {
+               fprintf(stderr, "%s: overwrite '%s'? ", applet_name, dest);
+               if (!bb_ask_confirmation())
+                       return 0; // not allowed to overwrite
+       }
+       if (unlink(dest) < 0) {
+               bb_perror_msg("cannot remove '%s'", dest);
+               return -1; // error
+       }
+       return 1; // ok (to try again)
+}
+
 int copy_file(const char *source, const char *dest, int flags)
 {
        struct stat source_stat;
        struct stat dest_stat;
-       int dest_exists = 0;
        int status = 0;
+       signed char dest_exists = 0;
+       signed char ovr;
 
-       if ((!(flags & FILEUTILS_DEREFERENCE) &&
-                       lstat(source, &source_stat) < 0) ||
-                       ((flags & FILEUTILS_DEREFERENCE) &&
-                        stat(source, &source_stat) < 0)) {
-               bb_perror_msg("%s", source);
+#define FLAGS_DEREF (flags & FILEUTILS_DEREFERENCE)
+
+       if ((FLAGS_DEREF ? stat : lstat)(source, &source_stat) < 0) {
+               // This may be a dangling symlink.
+               // Making [sym]links to dangling symlinks works, so...
+               if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK))
+                       goto make_links;
+               bb_perror_msg("cannot stat '%s'", source);
                return -1;
        }
 
        if (lstat(dest, &dest_stat) < 0) {
                if (errno != ENOENT) {
-                       bb_perror_msg("unable to stat `%s'", dest);
+                       bb_perror_msg("cannot stat '%s'", dest);
                        return -1;
                }
        } else {
-               if (source_stat.st_dev == dest_stat.st_dev &&
-                       source_stat.st_ino == dest_stat.st_ino)
-               {
-                       bb_error_msg("`%s' and `%s' are the same file", source, dest);
+               if (source_stat.st_dev == dest_stat.st_dev
+                && source_stat.st_ino == dest_stat.st_ino
+               {
+                       bb_error_msg("'%s' and '%s' are the same file", source, dest);
                        return -1;
                }
                dest_exists = 1;
@@ -46,14 +68,14 @@ int copy_file(const char *source, const char *dest, int flags)
                mode_t saved_umask = 0;
 
                if (!(flags & FILEUTILS_RECUR)) {
-                       bb_error_msg("%s: omitting directory", source);
+                       bb_error_msg("omitting directory '%s'", source);
                        return -1;
                }
 
                /* Create DEST.  */
                if (dest_exists) {
                        if (!S_ISDIR(dest_stat.st_mode)) {
-                               bb_error_msg("`%s' is not a directory", dest);
+                               bb_error_msg("target '%s' is not a directory", dest);
                                return -1;
                        }
                } else {
@@ -67,7 +89,7 @@ int copy_file(const char *source, const char *dest, int flags)
 
                        if (mkdir(dest, mode) < 0) {
                                umask(saved_umask);
-                               bb_perror_msg("cannot create directory `%s'", dest);
+                               bb_perror_msg("cannot create directory '%s'", dest);
                                return -1;
                        }
 
@@ -75,7 +97,8 @@ int copy_file(const char *source, const char *dest, int flags)
                }
 
                /* Recursively copy files in SOURCE.  */
-               if ((dp = opendir(source)) == NULL) {
+               dp = opendir(source);
+               if (dp == NULL) {
                        status = -1;
                        goto preserve_status;
                }
@@ -84,7 +107,7 @@ int copy_file(const char *source, const char *dest, int flags)
                        char *new_source, *new_dest;
 
                        new_source = concat_subpath_file(source, d->d_name);
-                       if(new_source == NULL)
+                       if (new_source == NULL)
                                continue;
                        new_dest = concat_path_file(dest, d->d_name);
                        if (copy_file(new_source, new_dest, flags) < 0)
@@ -92,103 +115,119 @@ int copy_file(const char *source, const char *dest, int flags)
                        free(new_source);
                        free(new_dest);
                }
-               /* closedir have only EBADF error, but "dp" not changes */
                closedir(dp);
 
-               if (!dest_exists &&
-                               chmod(dest, source_stat.st_mode & ~saved_umask) < 0) {
-                       bb_perror_msg("unable to change permissions of `%s'", dest);
+               if (!dest_exists
+                && chmod(dest, source_stat.st_mode & ~saved_umask) < 0
+               ) {
+                       bb_perror_msg("cannot change permissions of '%s'", dest);
                        status = -1;
                }
-       } else if (S_ISREG(source_stat.st_mode) ||
-                  (S_ISLNK(source_stat.st_mode) && (flags & FILEUTILS_DEREFERENCE)))
-       {
+
+       } else if (flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) {
+               int (*lf)(const char *oldpath, const char *newpath);
+ make_links:
+               // Hmm... maybe
+               // if (DEREF && MAKE_SOFTLINK) source = realpath(source) ?
+               // (but realpath returns NULL on dangling symlinks...)
+               lf = (flags & FILEUTILS_MAKE_SOFTLINK) ? symlink : link;
+               if (lf(source, dest) < 0) {
+                       ovr = retry_overwrite(dest, flags);
+                       if (ovr <= 0)
+                               return ovr;
+                       if (lf(source, dest) < 0) {
+                               bb_perror_msg("cannot create link '%s'", dest);
+                               return -1;
+                       }
+               }
+               return 0;
+
+       } else if (S_ISREG(source_stat.st_mode)
+       // Huh? DEREF uses stat, which never returns links IIRC...
+        || (FLAGS_DEREF && S_ISLNK(source_stat.st_mode)) 
+       ) {
                int src_fd;
                int dst_fd;
                if (ENABLE_FEATURE_PRESERVE_HARDLINKS) {
                        char *link_name;
 
-                       if (!(flags & FILEUTILS_DEREFERENCE) &&
-                                       is_in_ino_dev_hashtable(&source_stat, &link_name)) {
+                       if (!FLAGS_DEREF
+                        && is_in_ino_dev_hashtable(&source_stat, &link_name)
+                       ) {
                                if (link(link_name, dest) < 0) {
-                                       bb_perror_msg("unable to link `%s'", dest);
-                                       return -1;
+                                       ovr = retry_overwrite(dest, flags);
+                                       if (ovr <= 0)
+                                               return ovr;
+                                       if (link(link_name, dest) < 0) {
+                                               bb_perror_msg("cannot create link '%s'", dest);
+                                               return -1;
+                                       }
                                }
-
                                return 0;
                        }
+                       // TODO: probably is_in_.. and add_to_...
+                       // can be combined: find_or_add_...
                        add_to_ino_dev_hashtable(&source_stat, dest);
                }
+
                src_fd = open(source, O_RDONLY);
                if (src_fd == -1) {
-                       bb_perror_msg("unable to open `%s'", source);
-                       return(-1);
+                       bb_perror_msg("cannot open '%s'", source);
+                       return -1;
                }
 
-               if (dest_exists) {
-                       if (flags & FILEUTILS_INTERACTIVE) {
-                               fprintf(stderr, "%s: overwrite `%s'? ", bb_applet_name, dest);
-                               if (!bb_ask_confirmation()) {
-                                       close (src_fd);
-                                       return 0;
-                               }
-                       }
-
-                       dst_fd = open(dest, O_WRONLY|O_TRUNC);
-                       if (dst_fd == -1) {
-                               if (!(flags & FILEUTILS_FORCE)) {
-                                       bb_perror_msg("unable to open `%s'", dest);
-                                       close(src_fd);
-                                       return -1;
-                               }
-
-                               if (unlink(dest) < 0) {
-                                       bb_perror_msg("unable to remove `%s'", dest);
-                                       close(src_fd);
-                                       return -1;
-                               }
-
-                               goto dest_removed;
+               // POSIX: if exists and -i, ask (w/o -i assume yes).
+               // Then open w/o EXCL.
+               // If open still fails and -f, try unlink, then try open again.
+               // Result: a mess:
+               // If dest is a softlink, we overwrite softlink's destination!
+               // (or fail, if it points to dir/nonexistent location/etc).
+               // This is strange, but POSIX-correct.
+               // coreutils cp has --remove-destination to override this...
+               dst_fd = open(dest, (flags & FILEUTILS_INTERACTIVE)
+                               ? O_WRONLY|O_CREAT|O_TRUNC|O_EXCL
+                               : O_WRONLY|O_CREAT|O_TRUNC, source_stat.st_mode);
+               if (dst_fd == -1) {
+                       // We would not do POSIX insanity. -i asks,
+                       // then _unlinks_ the offender. Presto.
+                       // Or else we will end up having 3 open()s!
+                       ovr = retry_overwrite(dest, flags);
+                       if (ovr <= 0) {
+                               close(src_fd);
+                               return ovr;
                        }
-               } else {
-dest_removed:
-                       dst_fd = open(dest, O_WRONLY|O_CREAT, source_stat.st_mode);
+                       dst_fd = open(dest, O_WRONLY|O_CREAT|O_TRUNC, source_stat.st_mode);
                        if (dst_fd == -1) {
-                               bb_perror_msg("unable to open `%s'", dest);
+                               bb_perror_msg("cannot open '%s'", dest);
                                close(src_fd);
-                               return(-1);
+                               return -1;
                        }
                }
 
                if (bb_copyfd_eof(src_fd, dst_fd) == -1)
                        status = -1;
-
                if (close(dst_fd) < 0) {
-                       bb_perror_msg("unable to close `%s'", dest);
+                       bb_perror_msg("cannot close '%s'", dest);
                        status = -1;
                }
-
                if (close(src_fd) < 0) {
-                       bb_perror_msg("unable to close `%s'", source);
+                       bb_perror_msg("cannot close '%s'", source);
                        status = -1;
                }
-       } else if (S_ISBLK(source_stat.st_mode) || S_ISCHR(source_stat.st_mode) ||
-           S_ISSOCK(source_stat.st_mode) || S_ISFIFO(source_stat.st_mode) ||
-           S_ISLNK(source_stat.st_mode)) {
 
+       } else if (S_ISBLK(source_stat.st_mode) || S_ISCHR(source_stat.st_mode)
+        || S_ISSOCK(source_stat.st_mode) || S_ISFIFO(source_stat.st_mode)
+        || S_ISLNK(source_stat.st_mode)
+       ) {
+               // We are lazy here, a bit lax with races...
                if (dest_exists) {
-                       if((flags & FILEUTILS_FORCE) == 0) {
-                               fprintf(stderr, "`%s' exists\n", dest);
-                               return -1;
-                       }
-                       if(unlink(dest) < 0) {
-                               bb_perror_msg("unable to remove `%s'", dest);
-                               return -1;
-                       }
+                       ovr = retry_overwrite(dest, flags);
+                       if (ovr <= 0)
+                               return ovr;
                }
                if (S_ISFIFO(source_stat.st_mode)) {
                        if (mkfifo(dest, source_stat.st_mode) < 0) {
-                               bb_perror_msg("cannot create fifo `%s'", dest);
+                               bb_perror_msg("cannot create fifo '%s'", dest);
                                return -1;
                        }
                } else if (S_ISLNK(source_stat.st_mode)) {
@@ -196,20 +235,21 @@ dest_removed:
 
                        lpath = xreadlink(source);
                        if (symlink(lpath, dest) < 0) {
-                               bb_perror_msg("cannot create symlink `%s'", dest);
+                               bb_perror_msg("cannot create symlink '%s'", dest);
+                               free(lpath);
                                return -1;
                        }
                        free(lpath);
 
                        if (flags & FILEUTILS_PRESERVE_STATUS)
                                if (lchown(dest, source_stat.st_uid, source_stat.st_gid) < 0)
-                                       bb_perror_msg("unable to preserve ownership of `%s'", dest);
+                                       bb_perror_msg("cannot preserve %s of '%s'", "ownership", dest);
 
                        return 0;
 
                } else {
                        if (mknod(dest, source_stat.st_mode, source_stat.st_rdev) < 0) {
-                               bb_perror_msg("unable to create `%s'", dest);
+                               bb_perror_msg("cannot create '%s'", dest);
                                return -1;
                        }
                }
@@ -218,22 +258,24 @@ dest_removed:
                return -1;
        }
 
-preserve_status:
+ preserve_status:
 
-       if (flags & FILEUTILS_PRESERVE_STATUS) {
+       if (flags & FILEUTILS_PRESERVE_STATUS
+       /* Cannot happen: */
+       /* && !(flags & (FILEUTILS_MAKE_SOFTLINK|FILEUTILS_MAKE_HARDLINK)) */
+       ) {
                struct utimbuf times;
-               char *msg="unable to preserve %s of `%s'";
 
                times.actime = source_stat.st_atime;
                times.modtime = source_stat.st_mtime;
                if (utime(dest, &times) < 0)
-                       bb_perror_msg(msg, "times", dest);
+                       bb_perror_msg("cannot preserve %s of '%s'", "times", dest);
                if (chown(dest, source_stat.st_uid, source_stat.st_gid) < 0) {
                        source_stat.st_mode &= ~(S_ISUID | S_ISGID);
-                       bb_perror_msg(msg, "ownership", dest);
+                       bb_perror_msg("cannot preserve %s of '%s'", "ownership", dest);
                }
                if (chmod(dest, source_stat.st_mode) < 0)
-                       bb_perror_msg(msg, "permissions", dest);
+                       bb_perror_msg("cannot preserve %s of '%s'", "permissions", dest);
        }
 
        return status;