Module Name: src
Committed By: kre
Date: Mon Jul 22 17:34:31 UTC 2019
Modified Files:
src/usr.bin/printf: printf.c
Log Message:
Amend the previous change: we can have (almost) the best of both
worlds, as when the first arg (which should be the format) contains
no % conversions, and there are more args, the results are unspecified
(according to POSIX).
We can use this so the previous usage
printf -- format arg...
(which is stupid, and pointless, but used to work) continues to
simply ignore the -- (unspecified results mean we can do whatever
feels good...)
This brings back the #if 0'd block from the previous modification
(so there is no longer anything that needs cleaning up later) but runs
the getopt() loop it contained only when there are at least 2 args
(so any 1 arg printf always uses that arg as the format string,
whatever it contains, including just "--") and also only when the
first (format) arg contains no '%' characters (which guarantees no %
conversions without needing to actually parse the arg). This is the
(or a) "unspecified results" case from POSIX, so we are free to do
anything we like - including assuming that we might have options
(we don't) and pretending to process them.
To generate a diff of this commit:
cvs rdiff -u -r1.49 -r1.50 src/usr.bin/printf/printf.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/usr.bin/printf/printf.c
diff -u src/usr.bin/printf/printf.c:1.49 src/usr.bin/printf/printf.c:1.50
--- src/usr.bin/printf/printf.c:1.49 Sun Jul 21 15:25:39 2019
+++ src/usr.bin/printf/printf.c Mon Jul 22 17:34:31 2019
@@ -1,4 +1,4 @@
-/* $NetBSD: printf.c,v 1.49 2019/07/21 15:25:39 kre Exp $ */
+/* $NetBSD: printf.c,v 1.50 2019/07/22 17:34:31 kre Exp $ */
/*
* Copyright (c) 1989, 1993
@@ -41,7 +41,7 @@ __COPYRIGHT("@(#) Copyright (c) 1989, 19
#if 0
static char sccsid[] = "@(#)printf.c 8.2 (Berkeley) 3/22/95";
#else
-__RCSID("$NetBSD: printf.c,v 1.49 2019/07/21 15:25:39 kre Exp $");
+__RCSID("$NetBSD: printf.c,v 1.50 2019/07/22 17:34:31 kre Exp $");
#endif
#endif /* not lint */
@@ -138,27 +138,39 @@ main(int argc, char *argv[])
rval = 0; /* clear for builtin versions (avoid holdover) */
-#if 0
- int o;
-
/*
* printf does not comply with Posix XBD 12.2 - there are no opts,
* not even the -- end of options marker. Do not run getoot().
*/
- while ((o = getopt(argc, argv, "")) != -1) {
- switch (o) {
- case '?':
- default:
- usage();
- return 1;
+ if (argc > 2 && strchr(argv[1], '%') == NULL) {
+ int o;
+
+ /*
+ * except that if there are multiple args and
+ * the first (the nominal format) contains no '%'
+ * conversions (which we will approximate as no '%'
+ * characters at all, conversions or not) then the
+ * results are unspecified, and we can do what we
+ * like. So in that case, for some backward compat
+ * to scripts which (stupidly) do:
+ * printf -- format args
+ * process this case the old way.
+ */
+
+ while ((o = getopt(argc, argv, "")) != -1) {
+ switch (o) {
+ case '?':
+ default:
+ usage();
+ return 1;
+ }
}
+ argc -= optind;
+ argv += optind;
+ } else {
+ argc -= 1; /* drop argv[0] (the program name) */
+ argv += 1;
}
- argc -= optind;
- argv += optind;
-#else
- argc -= 1;
- argv += 1;
-#endif
if (argc < 1) {
usage();
