From fa96aa8d70eb1dfd7b3550fab417a43b3a507a6d Mon Sep 17 00:00:00 2001
From: Ron Yorston <rmy@pobox.com>
Date: Sat, 5 Jan 2019 14:16:50 +0000
Subject: busybox: add --uninstall option

Add an option to allow hard links to be removed.

   busybox --uninstall file

removes all hard links to the given file (including the file itself.)
Since Microsoft Windows refuses to delete a running executable a
BusyBox binary is unable to remove links to itself.

   busybox --uninstall -n file

displays the names of all hard links to the given file.

Although this feature is couched in terms of uninstalling BusyBox
it's actually quite general:  it can be used to delete or display
hard links to any file.
---
 libbb/appletlib.c | 34 ++++++++++++++++++++++++++++++++--
 1 file changed, 32 insertions(+), 2 deletions(-)

(limited to 'libbb')

diff --git a/libbb/appletlib.c b/libbb/appletlib.c
index 11136de11..8a66b3303 100644
--- a/libbb/appletlib.c
+++ b/libbb/appletlib.c
@@ -776,7 +776,8 @@ static void install_links(const char *busybox,
 	while (*appname) {
 		fpc = xasprintf("%s/%s.exe", custom_install_dir, appname);
 		rc = link(busybox, fpc);
-		if (rc != 0 && errno != EEXIST) {
+		if (rc != 0 && (errno != EEXIST ||
+				strcmp("busybox.exe", bb_basename(fpc)) != 0)) {
 			bb_simple_perror_msg(fpc);
 		}
 		free(fpc);
@@ -885,7 +886,13 @@ int busybox_main(int argc UNUSED_PARAM, char **argv)
 			"   or: busybox --show SCRIPT\n"
 #  endif
 			IF_FEATURE_INSTALLER(
-			"   or: busybox --install "IF_NOT_PLATFORM_MINGW32("[-s] ")"[DIR]\n"
+			IF_NOT_PLATFORM_MINGW32(
+			"   or: busybox --install [-s] [DIR]\n"
+			)
+			IF_PLATFORM_MINGW32(
+			"   or: busybox --install [DIR]\n"
+			"   or: busybox --uninstall [-n] file\n"
+			)
 			)
 			"   or: function [arguments]...\n"
 			"\n"
@@ -1016,6 +1023,29 @@ int busybox_main(int argc UNUSED_PARAM, char **argv)
 		return 0;
 	}
 
+#if ENABLE_PLATFORM_MINGW32 && ENABLE_FEATURE_INSTALLER
+	if (strcmp(argv[1], "--uninstall") == 0) {
+		char name[PATH_MAX];
+		int dry_run = (argv[2] && strcmp(argv[2], "-n") == 0 && ++argv);
+		const char *file = argv[2];
+
+		if (!argv[2])
+			bb_error_msg_and_die(bb_msg_requires_arg, "--uninstall");
+
+		while (enumerate_links(file, name)) {
+			if (dry_run) {
+				full_write1_str(name);
+				full_write1_str("\n");
+			}
+			else if (unlink(name) != 0) {
+				bb_simple_perror_msg(name);
+			}
+			file = NULL;
+		}
+		return 0;
+	}
+#endif
+
 	if (strcmp(argv[1], "--help") == 0) {
 		/* "busybox --help [<applet>]" */
 		if (!argv[2])
-- 
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