svn commit: r345130 - head/usr.sbin/trim

[Eugene Grosbein]

Author: eugen
Date: Thu Mar 14 12:25:16 2019
New Revision: 345130
URL: https://svnweb.freebsd.org/changeset/base/345130

Log:
  trim(8): add another safety net
  
  It is quite easy make a mistake and run something like this:
  
  	trim -f /dev/da0 -r rfile
  
  This would trim the whole device then emit an error on non-existing file -r.
  
  Add another check to prevent this while allowing this form still
  for real object names beginning from dash:
  
  	trim -f -- /dev/da0 -r rfile
  
  MFC after:	1 week

Modified:
  head/usr.sbin/trim/trim.c

Modified: head/usr.sbin/trim/trim.c
==============================================================================
--- head/usr.sbin/trim/trim.c	Thu Mar 14 10:06:46 2019	(r345129)
+++ head/usr.sbin/trim/trim.c	Thu Mar 14 12:25:16 2019	(r345130)
@@ -40,6 +40,7 @@
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <sysexits.h>
 #include <unistd.h>
 
@@ -103,6 +104,23 @@ main(int argc, char **argv)
 			usage(name);
 			/* NOTREACHED */
 		}
+
+	/*
+	 * Safety net: do not allow mistakes like
+	 *
+	 *	trim -f /dev/da0 -r rfile
+	 *
+	 * This would trim whole device then error on non-existing file -r.
+	 * Following check prevents this while allowing this form still:
+	 *
+	 *	trim -f -- /dev/da0 -r rfile
+	 */
+	
+	if (strcmp(argv[optind-1], "--") != 0) {
+		for (ch = optind; ch < argc; ch++)
+			if (argv[ch][0] == '-')
+				usage(name);
+	}
 
 	argv += optind;
 	argc -= optind;