Re: a little extra cmdline help. [PATCH]

Message-Id: <409FF333.4020104@divsol.com>

p4raw-id: //depot/perl@22806

1 files changed, 39 insertions, 6 deletions

diff --git a/perl.c b/perl.c
index 3375099f79..e4301a0b91 100644
--- a/perl.c
+++ b/perl.c
@@ -2382,6 +2382,33 @@ NULL
 int
 Perl_get_debug_opts(pTHX_ char **s)
 {
+    static char *usage_msgd[] = {
+      " Debugging flag values: (see also -d)",
+      "  p  Tokenizing and parsing (with v, displays parse stack)",
+      "  s  Stack snapshots. with v, displays all stacks",
+      "  l  Context (loop) stack processing",
+      "  t  Trace execution",
+      "  o  Method and overloading resolution",
+      "  c  String/numeric conversions",
+      "  P  Print profiling info, preprocessor command for -P, source file input state",
+      "  m  Memory allocation",
+      "  f  Format processing",
+      "  r  Regular expression parsing and execution",
+      "  x  Syntax tree dump",
+      "  u  Tainting checks (Obsolete, previously used for LEAKTEST)",
+      "  H  Hash dump -- usurps values()",
+      "  X  Scratchpad allocation",
+      "  D  Cleaning up",
+      "  S  Thread synchronization",
+      "  T  Tokenising",
+      "  R  Include reference counts of dumped variables (eg when using -Ds)",
+      "  J  Do not s,t,P-debug (Jump over) opcodes within package DB",
+      "  v  Verbose: use in conjunction with other flags",
+      "  C  Copy On Write",
+      "  A  Consistency checks on internal structures",
+      "  q  quiet - currently only suppressed the 'EXECUTING' message",
+      NULL
+    };
     int i = 0;
     if (isALPHA(**s)) {
 	/* if adding extra options, remember to update DEBUG_MASK */
@@ -2392,14 +2419,18 @@ Perl_get_debug_opts(pTHX_ char **s)
 	    if (d)
 		i |= 1 << (d - debopts);
 	    else if (ckWARN_d(WARN_DEBUGGING))
-		Perl_warner(aTHX_ packWARN(WARN_DEBUGGING),
-		    "invalid option -D%c\n", **s);
+	        Perl_warner(aTHX_ packWARN(WARN_DEBUGGING),
+		    "invalid option -D%c, use -D'' to see choices\n", **s);
 	}
     }
-    else {
+    else if (isDIGIT(**s)) {
 	i = atoi(*s);
 	for (; isALNUM(**s); (*s)++) ;
     }
+    else {
+      char **p = usage_msgd;
+      while (*p) PerlIO_printf(PerlIO_stdout(), "%s\n", *p++);
+    }
 #  ifdef EBCDIC
     if ((i & DEBUG_p_FLAG) && ckWARN_d(WARN_DEBUGGING))
 	Perl_warner(aTHX_ packWARN(WARN_DEBUGGING),
@@ -2514,7 +2545,7 @@ Perl_moreswitches(pTHX_ char *s)
 #else /* !DEBUGGING */
 	if (ckWARN_d(WARN_DEBUGGING))
 	    Perl_warner(aTHX_ packWARN(WARN_DEBUGGING),
-	           "Recompile perl with -DDEBUGGING to use -D switch\n");
+	           "Recompile perl with -DDEBUGGING to use -D switch (did you mean -d ?)\n");
 	for (s++; isALNUM(*s); s++) ;
 #endif
 	/*SUPPRESS 530*/
@@ -3095,8 +3126,10 @@ S_open_script(pTHX_ char *scriptname, bool dosearch, SV *sv)
 #endif /* IAMSUID */
     if (!PL_rsfp) {
 /* PSz 16 Sep 03  Keep neat error message */
-            Perl_croak(aTHX_ "Can't open perl script \"%s\": %s\n",
-                       CopFILE(PL_curcop), Strerror(errno));
+        
+            Perl_croak(aTHX_ "Can't open perl script \"%s\": %s%s\n",
+                       CopFILE(PL_curcop), Strerror(errno),
+		       ".  Use -S to search $PATH for it");
     }
 }