library: let's make 'escaped_copy' multibyte aware too

This patch is intended to bring the master branch into
closer alignment with the newlib branch functionality.

The commit shown below replaced that 'escape_str' with
'escaped_copy' so that the ps program wouldn't execute
some code twice. However, it created a problem for the
top program when the UTF-8 encoding was not available.

Unlike ps who calls the escape functions directly, top
outputs those library provided strings unaltered. That
means there is no workaround (like LANG=) when such an
encoding was unavailable. This, in turn, can lead to a
corrupted display (especially with the linux console).

Now, when a UTF-8 encoding is not available, multibyte
chars are converted to '?', reducing display problems.

[ there's still a potential problem concerning 'cmd' ]
[ should program names contain multibyte characters. ]
[ unlike that newlib branch, this string is not ever ]
[ altered with the '?' char under the master branch. ]

Reference(s);
. Dec 2020, escaoed_copy repleced most escape_str
commit eea5626bb144328eb60e9ea8a29bd5b1f100ecd9

Signed-off-by: Jim Warner <james.warner@comcast.net>

diff --git a/proc/escape.c b/proc/escape.c
index 880dfd959d30ad0d130021f9946a884435d8daf8..2e8fb7dddaaa2aabe5b2733ef04310875ac78ccf 100644 (file)
--- a/proc/escape.c
+++ b/proc/escape.c
@@ -41,7 +41,20 @@
   if ((cells) <= 0) return 0; \
 } while (0)
 
+static const unsigned char ESC_tab[] = {
+  "@..............................."
+  "||||||||||||||||||||||||||||||||"
+  "||||||||||||||||||||||||||||||||"
+  "|||||||||||||||||||||||||||||||."
+  "????????????????????????????????"
+  "????????????????????????????????"
+  "????????????????????????????????"
+  "????????????????????????????????"
+};
+
+
 #if (__GNU_LIBRARY__ >= 6) && (!defined(__UCLIBC__) || defined(__UCLIBC_HAS_WCHAR__))
+
 static int escape_str_utf8(char *restrict dst, const char *restrict src, int bufsize, int *maxcells){
   int my_cells = 0;
   int my_bytes = 0;
@@ -105,23 +118,14 @@ static int escape_str_utf8(char *restrict dst, const char *restrict src, int buf
   *maxcells -= my_cells;
   return my_bytes;        // bytes of text, excluding the NUL
 }
-
 #endif /* __GNU_LIBRARY__  */
 
+
 /* sanitize a string via one-way mangle */
 int escape_str(char *restrict dst, const char *restrict src, int bufsize, int *maxcells){
   unsigned char c;
   int my_cells = 0;
   int my_bytes = 0;
-  const char codes[] =
-  "Z..............................."
-  "||||||||||||||||||||||||||||||||"
-  "||||||||||||||||||||||||||||||||"
-  "|||||||||||||||||||||||||||||||."
-  "????????????????????????????????"
-  "????????????????????????????????"
-  "????????????????????????????????"
-  "????????????????????????????????";
 
 #if (__GNU_LIBRARY__ >= 6) && (!defined(__UCLIBC__) || defined(__UCLIBC_HAS_WCHAR__))
   static int utf_init=0;
@@ -145,7 +149,7 @@ int escape_str(char *restrict dst, const char *restrict src, int bufsize, int *m
       break;
     c = (unsigned char) *(src++);
     if(!c) break;
-    if(codes[c]!='|') c=codes[c];
+    if(ESC_tab[c]!='|') c=ESC_tab[c];
     my_cells++;
     my_bytes++;
     *(dst++) = c;
@@ -225,8 +229,14 @@ int escape_command(char *restrict const outbuf, const proc_t *restrict const pp,
 // copy a string, but 'escape' any control characters
 // using the traditional escape.h calling conventions
 int escaped_copy(char *restrict dst, const char *restrict src, int bufsize, int *maxroom){
+  static int utf_sw = 0;
   int i, n;
+  char c;
 
+  if(utf_sw == 0){
+     char *enc = nl_langinfo(CODESET);
+     utf_sw = enc && strcasecmp(enc, "UTF-8")==0 ? 1 : -1;
+  }
   SECURE_ESCAPE_ARGS(dst, bufsize, *maxroom);
   if (bufsize > *maxroom+1) bufsize = *maxroom+1;
 
@@ -237,11 +247,17 @@ int escaped_copy(char *restrict dst, const char *restrict src, int bufsize, int
   }
   if (n >= bufsize) n = bufsize-1;
 
-  // control chars, especially tabs, create alignment problems for ps & top ...
-  for (i = 0; i < n; i++)
-    if ((unsigned char)dst[i] < 0x20 || dst[i] == 0x7f)
-      dst[i] = '?';
-
+  if (utf_sw < 0) {
+    // if bad locale, replace the non-printing stuff
+    for (i = 0; i < n; i++)
+      if ((c = ESC_tab[(unsigned char)dst[i]]) != '|')
+        dst[i] = c;
+  } else {
+    // or eliminate those non-printing control chars
+    for (i = 0; i < n; i++)
+      if ((unsigned char)dst[i] < 0x20 || dst[i] == 0x7f)
+        dst[i] = '?';
+  }
   *maxroom -= n;
   return n;
 }