Module Name: src
Committed By: kre
Date: Tue Aug 6 07:48:16 UTC 2024
Modified Files:
src/usr.bin/printf: printf.c
Log Message:
PR bin/58534 -- printf(1) source code comment fix
Update the comment near the start of main() in printf.c so it
explains what is really happening and why, rather than being a
whole bunch of incorrect BS about what posix does or doesn't require.
This changes comments only, NFC (should be no binary change at all).
To generate a diff of this commit:
cvs rdiff -u -r1.55 -r1.56 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:1.55 src/usr.bin/printf/printf.c:1.56
--- src/usr.bin/printf/printf.c:1.55 Thu Jul 18 12:08:11 2024
+++ src/usr.bin/printf/printf.c Tue Aug 6 07:48:16 2024
@@ -1,4 +1,4 @@
-/* $NetBSD: printf.c,v 1.55 2024/07/18 12:08:11 wiz Exp $ */
+/* $NetBSD: printf.c,v 1.56 2024/08/06 07:48:16 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 1.55 2024/07/18 12:08:11 wiz Exp $");
+__RCSID("$NetBSD: printf.c,v 1.56 2024/08/06 07:48:16 kre Exp $");
#endif
#endif /* not lint */
@@ -144,23 +144,33 @@ main(int argc, char *argv[])
rval = 0; /* clear for builtin versions (avoid holdover) */
clearerr(stdout); /* for the builtin version */
- /*
- * printf does not comply with Posix XBD 12.2 - there are no opts,
- * not even the -- end of options marker. Do not run getopt().
- */
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.
+ * We only do this for argc > 2, as:
+ *
+ * for argc <= 1
+ * at best we have a bare "printf" so there cannot be
+ * any options, thus getopts() would be a waste of time.
+ * The usage() below is assured.
+ *
+ * for argc == 2
+ * There is only one arg (argv[1]) which logically must
+ * be intended to be the (required) format string for
+ * printf, without which we can do nothing so rather
+ * than usage() if it happens to start with a '-' we
+ * just avoid getopts() and treat it as a format string.
+ *
+ * Then, for argc > 2, we also skip this if there is a '%'
+ * anywhere in argv[1] as it is likely that would be intended
+ * to be the format string, rather than options, even if it
+ * starts with a '-' so we skip getopts() in that case as well.
+ *
+ * Note that this would fail should there ever be an option
+ * which takes an arbitrary string value, which could be given
+ * as -Oabc%def so should that ever become possible, remove
+ * the strchr() test above.
*/
while ((o = getopt(argc, argv, "")) != -1) {
@@ -178,13 +188,13 @@ main(int argc, char *argv[])
argv += 1;
}
- if (argc < 1) {
+ if (argc < 1) { /* Nothing left at all? */
usage();
return 1;
}
- format = *argv;
- gargv = ++argv;
+ format = *argv; /* First remaining arg is the format string */
+ gargv = ++argv; /* remaining args are for that to consume */
#define SKIP1 "#-+ 0'"
#define SKIP2 "0123456789"
