Add +pc {latin1|unicode} switch and io:printable_range/0

This is the base for implementing configurable
~tp printouts, so that the user can define which
characters to view as actually printable in the shell and
by io_lib:format.

The functionality is neither documented nor used in this commit

6 files changed, 78 insertions, 7 deletions

diff --git a/erts/emulator/beam/bif.tab b/erts/emulator/beam/bif.tab
index b74dc5c3fe..8bc994c8c3 100644
--- a/erts/emulator/beam/bif.tab
+++ b/erts/emulator/beam/bif.tab
@@ -569,6 +569,8 @@ bif erlang:float_to_binary/1
 bif erlang:float_to_binary/2
 bif erlang:binary_to_float/1
 
+bif io:printable_range/0
+
 #
 # Obsolete
 #
diff --git a/erts/emulator/beam/erl_init.c b/erts/emulator/beam/erl_init.c
index ec3e0d54cb..83853dcd43 100644
--- a/erts/emulator/beam/erl_init.c
+++ b/erts/emulator/beam/erl_init.c
@@ -496,7 +496,7 @@ void erts_usage(void)
 
     erts_fprintf(stderr, "-d          don't write a crash dump for internally detected errors\n");
     erts_fprintf(stderr, "            (halt(String) will still produce a crash dump)\n");
-
+    erts_fprintf(stderr, "-fn[u|a|l]  Control how filenames are interpreted\n");
     erts_fprintf(stderr, "-hms size   set minimum heap size in words (default %d)\n",
 	       H_DEFAULT_SIZE);
     erts_fprintf(stderr, "-hmbs size  set minimum binary virtual heap size in words (default %d)\n",
@@ -509,7 +509,7 @@ void erts_usage(void)
     erts_fprintf(stderr, "            Note that this flag is deprecated!\n");
     erts_fprintf(stderr, "-M<X> <Y>   memory allocator switches,\n");
     erts_fprintf(stderr, "            see the erts_alloc(3) documentation for more info.\n");
-
+    erts_fprintf(stderr, "-pc <set>   Control what characters are considered printable (default latin1)\n");
     erts_fprintf(stderr, "-P number   set maximum number of processes on this node,\n");
     erts_fprintf(stderr, "            valid range is [%d-%d]\n",
 		 ERTS_MIN_PROCESSES, ERTS_MAX_PROCESSES);
@@ -979,13 +979,30 @@ erl_start(int argc, char **argv)
 	    VERBOSE(DEBUG_SYSTEM,
                     ("using display items %d\n",display_items));
 	    break;
+	case 'p':
+	    if (!strncmp(argv[i],"-pc",3)) {
+		int printable_chars = ERL_PRINTABLE_CHARACTERS_LATIN1;
+		arg = get_arg(argv[i]+3, argv[i+1], &i);
+		if (!strcmp(arg,"unicode")) {
+		    printable_chars = ERL_PRINTABLE_CHARACTERS_UNICODE;
+		} else if (strcmp(arg,"latin1")) {
+		    erts_fprintf(stderr, "bad range of printable "
+				 "characters: %s\n", arg);
+		    erts_usage();
+		}
+		erts_set_printable_characters(printable_chars);
+		break;
+	    } else {
+		erts_fprintf(stderr, "%s unknown flag %s\n", argv[0], argv[i]);
+		erts_usage();
+	    }
 	case 'f':
 	    if (!strncmp(argv[i],"-fn",3)) {
 		int warning_type =  ERL_FILENAME_WARNING_WARNING;
 		arg = get_arg(argv[i]+3, argv[i+1], &i);
 		switch (*arg) {
 		case 'u':
-		    switch (*(argv[i]+4)) {
+		    switch (*(arg+1)) {
 		    case 'w':
 		    case 0:
 			break;
@@ -997,7 +1014,7 @@ erl_start(int argc, char **argv)
 			break;
 		    default:
 			erts_fprintf(stderr, "bad type of warnings for "
-				     "wrongly coded filename: %s\n", argv[i]+4);
+				     "wrongly coded filename: %s\n", arg+1);
 			erts_usage();
 		    }
 		    erts_set_user_requested_filename_encoding
@@ -1014,7 +1031,7 @@ erl_start(int argc, char **argv)
 			 );
 		    break;
 		case 'a':
-		    switch (*(argv[i]+4)) {
+		    switch (*(arg+1)) {
 		    case 'w':
 		    case 0:
 			break;
@@ -1026,7 +1043,7 @@ erl_start(int argc, char **argv)
 			break;
 		    default:
 			erts_fprintf(stderr, "bad type of warnings for "
-				     "wrongly coded filename: %s\n", argv[i]+4);
+				     "wrongly coded filename: %s\n", arg+1);
 			erts_usage();
 		    }
 		    erts_set_user_requested_filename_encoding
diff --git a/erts/emulator/beam/erl_unicode.c b/erts/emulator/beam/erl_unicode.c
index 80982f3760..fa53fd0937 100644
--- a/erts/emulator/beam/erl_unicode.c
+++ b/erts/emulator/beam/erl_unicode.c
@@ -2747,3 +2747,11 @@ int erts_utf8_to_latin1(byte* dest, const byte* source, int slen)
     return dp - dest;
 }
 
+BIF_RETTYPE io_printable_range_0(BIF_ALIST_0)
+{
+    if (erts_get_printable_characters() == ERL_PRINTABLE_CHARACTERS_UNICODE) {
+	BIF_RET(am_unicode);
+    } else {
+	BIF_RET(am_latin1);
+    }
+}
diff --git a/erts/emulator/beam/sys.h b/erts/emulator/beam/sys.h
index 9416a91480..05bff430e3 100644
--- a/erts/emulator/beam/sys.h
+++ b/erts/emulator/beam/sys.h
@@ -1040,11 +1040,24 @@ char* win32_errorstr(int);
 #define ERL_FILENAME_WARNING_IGNORE (1)
 #define ERL_FILENAME_WARNING_ERROR (2)
 
+/***********************************************************************
+ * The user can request a range of character that he/she consider
+ * printable. Currently this can be either latin1 or unicode, but
+ * in the future a set of ranges, or languages, could be specified.
+ ***********************************************************************/
+#define ERL_PRINTABLE_CHARACTERS_LATIN1 (0)
+#define ERL_PRINTABLE_CHARACTERS_UNICODE (1)
+
 int erts_get_native_filename_encoding(void);
 /* The set function is only to be used by erl_init! */
 void erts_set_user_requested_filename_encoding(int encoding, int warning);
 int erts_get_user_requested_filename_encoding(void);
 int erts_get_filename_warning_type(void);
+/* This function is called from erl_init. The setting is read by BIF's 
+   in io/io_lib. Setting is not atomic. */
+void erts_set_printable_characters(int range);
+/* Get the setting (ERL_PRINTABLE_CHARACTERS_{LATIN1|UNICODE} */
+int erts_get_printable_characters(void);
 
 void erts_init_sys_common_misc(void);
 
diff --git a/erts/emulator/sys/common/erl_sys_common_misc.c b/erts/emulator/sys/common/erl_sys_common_misc.c
index 0b31c125e5..31ad3b82d5 100644
--- a/erts/emulator/sys/common/erl_sys_common_misc.c
+++ b/erts/emulator/sys/common/erl_sys_common_misc.c
@@ -49,10 +49,15 @@
 static int filename_encoding = ERL_FILENAME_UNKNOWN;
 static int filename_warning = ERL_FILENAME_WARNING_WARNING;
 #if defined(__WIN32__) || defined(__DARWIN__)
-static int user_filename_encoding = ERL_FILENAME_UTF8; /* Default unicode on windows */
+/* Default unicode on windows and MacOS X */
+static int user_filename_encoding = ERL_FILENAME_UTF8; 
 #else
 static int user_filename_encoding = ERL_FILENAME_LATIN1;
 #endif
+/* This controls the heuristic in printing characters in shell and w/ 
+   io:format("~tp", ...) etc. */
+static int printable_character_set = ERL_PRINTABLE_CHARACTERS_LATIN1;
+
 void erts_set_user_requested_filename_encoding(int encoding, int warning)
 {
     user_filename_encoding = encoding;
@@ -69,6 +74,15 @@ int erts_get_filename_warning_type(void)
     return filename_warning;
 }
 
+void erts_set_printable_characters(int range) {
+    /* Not an atomic */
+    printable_character_set = range;
+}
+
+int erts_get_printable_characters(void) {
+    return  printable_character_set;
+}
+
 void erts_init_sys_common_misc(void)
 {
 #if defined(__WIN32__)
diff --git a/erts/etc/common/erlexec.c b/erts/etc/common/erlexec.c
index 577554c43d..02615f9ef1 100644
--- a/erts/etc/common/erlexec.c
+++ b/erts/etc/common/erlexec.c
@@ -145,6 +145,13 @@ static char *plusr_val_switches[] = {
     NULL
 };
 
+/* +pc arguments with values */
+static char *pluspc_val_switches[] = {
+    "latin1",
+    "unicode",
+    NULL
+};
+
 /* +z arguments with values */
 static char *plusz_val_switches[] = {
     "dbbl",
@@ -912,6 +919,16 @@ int main(int argc, char **argv)
 			  i++;
 		      }
 		      break;
+		  case 'p':
+		      if (argv[i][2] != 'c' || argv[i][3] != '\0')
+			  goto the_default;
+		      if (i+1 >= argc)
+			  usage(argv[i]);
+		      argv[i][0] = '-';
+		      add_Eargs(argv[i]);
+		      add_Eargs(argv[i+1]);
+		      i++;
+		      break;
 		  case 'z':
 		      if (!is_one_of_strings(&argv[i][2], plusz_val_switches)) {
 			  goto the_default;