diff options
Diffstat (limited to 'src/ln.c')
| -rw-r--r-- | src/ln.c | 63 |
1 files changed, 34 insertions, 29 deletions
@@ -39,26 +39,15 @@ proper_name ("Mike Parker"), \ proper_name ("David MacKenzie") -/* In being careful not even to try to make hard links to directories, - we have to know whether link(2) follows symlinks. If it does, then - we have to *stat* the `source' to see if the resulting link would be - to a directory. Otherwise, we have to use *lstat* so that we allow - users to make hard links to symlinks-that-point-to-directories. */ - -#if LINK_FOLLOWS_SYMLINKS -# define STAT_LIKE_LINK(File, Stat_buf) \ - stat (File, Stat_buf) -#else -# define STAT_LIKE_LINK(File, Stat_buf) \ - lstat (File, Stat_buf) -#endif - /* FIXME: document */ static enum backup_type backup_type; /* If true, make symbolic links; otherwise, make hard links. */ static bool symbolic_link; +/* If true, hard links are logical rather than physical. */ +static bool logical = !!LINK_FOLLOWS_SYMLINKS; + /* If true, ask the user before removing existing files. */ static bool interactive; @@ -71,7 +60,7 @@ static bool verbose; /* If true, allow the superuser to *attempt* to make hard links to directories. However, it appears that this option is not useful in practice, since even the superuser is prohibited from hard-linking - directories on most (all?) existing systems. */ + directories on most existing systems (Solaris being an exception). */ static bool hard_dir_link; /* If nonzero, and the specified destination is a symbolic link to a @@ -99,6 +88,8 @@ static struct option const long_options[] = {"interactive", no_argument, NULL, 'i'}, {"suffix", required_argument, NULL, 'S'}, {"target-directory", required_argument, NULL, 't'}, + {"logical", no_argument, NULL, 'L'}, + {"physical", no_argument, NULL, 'P'}, {"symbolic", no_argument, NULL, 's'}, {"verbose", no_argument, NULL, 'v'}, {GETOPT_HELP_OPTION_DECL}, @@ -143,18 +134,15 @@ do_link (const char *source, const char *dest) bool source_is_dir = false; bool ok; - /* Use stat here instead of lstat. - On SVR4, link does not follow symlinks, so this check disallows - making hard links to symlinks that point to directories. Big deal. - On other systems, link follows symlinks, so this check is right. - - FIXME - POSIX 2008 added the AT_SYMLINK_FOLLOW flag to linkat so - that we can specify either behavior, via the new options -L - (hard-link to symlinks) and -P (hard-link to the referent). Once - gnulib has a decent implementation, we should use it here. */ if (!symbolic_link) { - if (STAT_LIKE_LINK (source, &source_stats) != 0) + /* Which stat to use depends on whether linkat will follow the + symlink. We can't use the shorter + (logical ? stat : lstat) (source, &source_stats) + since stat might be a function-like macro. */ + if ((logical ? stat (source, &source_stats) + : lstat (source, &source_stats)) + != 0) { error (0, errno, _("accessing %s"), quote (source)); return false; @@ -258,7 +246,9 @@ do_link (const char *source, const char *dest) } } - ok = ((symbolic_link ? symlink (source, dest) : link (source, dest)) + ok = ((symbolic_link ? symlink (source, dest) + : linkat (AT_FDCWD, source, AT_FDCWD, dest, + logical ? AT_SYMLINK_FOLLOW : 0)) == 0); /* If the attempt to create a link failed and we are removing or @@ -289,7 +279,9 @@ do_link (const char *source, const char *dest) return false; } - ok = ((symbolic_link ? symlink (source, dest) : link (source, dest)) + ok = ((symbolic_link ? symlink (source, dest) + : linkat (AT_FDCWD, source, AT_FDCWD, dest, + logical ? AT_SYMLINK_FOLLOW : 0)) == 0); } @@ -370,9 +362,11 @@ Mandatory arguments to long options are mandatory for short options too.\n\ -f, --force remove existing destination files\n\ "), stdout); fputs (_("\ + -i, --interactive prompt whether to remove destinations\n\ + -L, --logical make hard links to symbolic link references\n\ -n, --no-dereference treat destination that is a symlink to a\n\ directory as if it were a normal file\n\ - -i, --interactive prompt whether to remove destinations\n\ + -P, --physical make hard links directly to symbolic links\n\ -s, --symbolic make symbolic links instead of hard links\n\ "), stdout); fputs (_("\ @@ -391,6 +385,11 @@ The version control method may be selected via the --backup option or through\n\ the VERSION_CONTROL environment variable. Here are the values:\n\ \n\ "), stdout); + printf (_("\ +Using -s ignores -L and -P. Otherwise, the last option specified controls\n\ +behavior when the source is a symbolic link, defaulting to %s.\n\ +\n\ +"), LINK_FOLLOWS_SYMLINKS ? "-L" : "-P"); fputs (_("\ none, off never make backups (even if --backup is given)\n\ numbered, t make numbered backups\n\ @@ -430,7 +429,7 @@ main (int argc, char **argv) symbolic_link = remove_existing_files = interactive = verbose = hard_dir_link = false; - while ((c = getopt_long (argc, argv, "bdfinst:vFS:T", long_options, NULL)) + while ((c = getopt_long (argc, argv, "bdfinst:vFLPS:T", long_options, NULL)) != -1) { switch (c) @@ -452,9 +451,15 @@ main (int argc, char **argv) remove_existing_files = false; interactive = true; break; + case 'L': + logical = true; + break; case 'n': dereference_dest_dir_symlinks = false; break; + case 'P': + logical = false; + break; case 's': symbolic_link = true; break; |