1 files changed, 103 insertions, 0 deletions
diff --git a/util/sbase/ln.c b/util/sbase/ln.c
new file mode 100644
index 00000000..f62068a1
--- /dev/null
+++ b/util/sbase/ln.c
@@ -0,0 +1,103 @@
+/* See LICENSE file for copyright and license details. */
+#include <sys/stat.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <libgen.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "util.h"
+
+static void
+usage(void)
+{
+	eprintf("usage: %s [-f] [-L | -P | -s] target [name]\n"
+	        "       %s [-f] [-L | -P | -s] target ... dir\n", argv0, argv0);
+}
+
+int
+main(int argc, char *argv[])
+{
+	char *targetdir = ".", *target = NULL;
+	int ret = 0, sflag = 0, fflag = 0, dirfd = AT_FDCWD,
+	    hastarget = 0, flags = AT_SYMLINK_FOLLOW;
+	struct stat st, tst;
+
+	ARGBEGIN {
+	case 'f':
+		fflag = 1;
+		break;
+	case 'L':
+		flags |= AT_SYMLINK_FOLLOW;
+		break;
+	case 'P':
+		flags &= ~AT_SYMLINK_FOLLOW;
+		break;
+	case 's':
+		sflag = 1;
+		break;
+	default:
+		usage();
+	} ARGEND
+
+	if (!argc)
+		usage();
+
+	if (argc > 1) {
+		if (!stat(argv[argc - 1], &st) && S_ISDIR(st.st_mode)) {
+			if ((dirfd = open(argv[argc - 1], O_RDONLY)) < 0)
+				eprintf("open %s:", argv[argc - 1]);
+			targetdir = argv[argc - 1];
+			if (targetdir[strlen(targetdir) - 1] == '/')
+				targetdir[strlen(targetdir) - 1] = '\0';
+		} else if (argc == 2) {
+			hastarget = 1;
+			target = argv[argc - 1];
+		} else {
+			eprintf("%s: not a directory\n", argv[argc - 1]);
+		}
+		argv[argc - 1] = NULL;
+		argc--;
+	}
+
+	for (; *argv; argc--, argv++) {
+		if (!hastarget)
+			target = basename(*argv);
+
+		if (!sflag) {
+			if (stat(*argv, &st) < 0) {
+				weprintf("stat %s:", *argv);
+				ret = 1;
+				continue;
+			} else if (fstatat(dirfd, target, &tst, AT_SYMLINK_NOFOLLOW) < 0) {
+				if (errno != ENOENT) {
+					weprintf("fstatat %s %s:", targetdir, target);
+					ret = 1;
+					continue;
+				}
+			} else if (st.st_dev == tst.st_dev && st.st_ino == tst.st_ino) {
+				if (!fflag) {
+					weprintf("%s and %s/%s are the same file\n",
+							*argv, targetdir, target);
+					ret = 1;
+				}
+				continue;
+			}
+		}
+
+		if (fflag && unlinkat(dirfd, target, 0) < 0 && errno != ENOENT) {
+			weprintf("unlinkat %s %s:", targetdir, target);
+			ret = 1;
+			continue;
+		}
+		if ((sflag ? symlinkat(*argv, dirfd, target) :
+		             linkat(AT_FDCWD, *argv, dirfd, target, flags)) < 0) {
+			weprintf("%s %s <- %s/%s:", sflag ? "symlinkat" : "linkat",
+			         *argv, targetdir, target);
+			ret = 1;
+		}
+	}
+
+	return ret;
+}