1 files changed, 154 insertions, 0 deletions
diff --git a/lib/sh/strvis.c b/lib/sh/strvis.c
new file mode 100644
index 0000000..7a11d57
--- /dev/null
+++ b/lib/sh/strvis.c
@@ -0,0 +1,154 @@
+/* strvis.c - make unsafe graphical characters in a string visible. */
+
+/* Copyright (C) 2022 Free Software Foundation, Inc.
+
+   This file is part of GNU Bash, the Bourne Again SHell.
+   
+   Bash is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Bash is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Bash.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/* This is a stripped-down version suitable for the shell's use. */
+#include <config.h>
+
+#include <unistd.h>
+
+#include "bashansi.h"
+#include <stdio.h>
+
+#include "chartypes.h"
+#include "bashintl.h"
+#include "shmbutil.h"
+
+#define SAFECHAR(c)   ((c) == ' ' || (c) == '\t')
+
+#ifndef RUBOUT
+#define RUBOUT 0x7f
+#endif
+
+#ifndef CTRL_CHAR
+#define CTRL_CHAR(c)	((c) < 0x20)
+#endif
+
+#ifndef META_CHAR
+#define META_CHAR(c)	((c) > 0x7f && (c) <= UCHAR_MAX)
+#endif
+
+#ifndef UNCTRL
+#define UNCTRL(c)	(TOUPPER ((c) | 0x40))
+#endif
+
+#ifndef UNMETA
+#define UNMETA(c)	((c) & 0x7f)
+#endif
+
+int
+sh_charvis (s, sindp, slen, ret, rindp)
+     const char *s;
+     size_t *sindp;
+     size_t slen;
+     char *ret;
+     size_t *rindp;
+{
+  unsigned char c;
+  size_t si, ri;
+  const char *send;
+  DECLARE_MBSTATE;
+
+  si = *sindp;
+  ri = *rindp;
+  c = s[*sindp];
+
+#if defined (HANDLE_MULTIBYTE)
+  send = (locale_mb_cur_max > 1) ? s + slen : 0;
+#else
+  send = 0;
+#endif
+
+  if (SAFECHAR (c))
+    {
+      ret[ri++] = c;
+      si++;
+    }
+  else if (c == RUBOUT)
+    {
+      ret[ri++] = '^';
+      ret[ri++] = '?';
+      si++;
+    }
+  else if (CTRL_CHAR (c))
+    {
+      ret[ri++] = '^';
+      ret[ri++] = UNCTRL (c);
+      si++;
+    }
+#if defined (HANDLE_MULTIBYTE)
+  else if (locale_utf8locale && (c & 0x80))
+    COPY_CHAR_I (ret, ri, s, send, si);
+  else if (locale_mb_cur_max > 1 && is_basic (c) == 0)
+    COPY_CHAR_I (ret, ri, s, send, si);
+#endif
+  else if (META_CHAR (c))
+    {
+      ret[ri++] = 'M';
+      ret[ri++] = '-';
+      ret[ri++] = UNMETA (c);
+      si++;
+    }
+  else
+    ret[ri++] = s[si++];
+  
+  *sindp = si;
+  *rindp = ri;
+
+  return si;    
+}
+
+/* Return a new string with `unsafe' non-graphical characters in S rendered
+   in a visible way. */
+char *
+sh_strvis (string)
+     const char *string;
+{
+  size_t slen, sind;
+  char *ret;
+  size_t retind, retsize;
+  unsigned char c;
+  DECLARE_MBSTATE;
+
+  if (string == 0)
+    return 0;
+  if (*string == '\0')
+    {
+      if ((ret = (char *)malloc (1)) == 0)
+	return 0;
+      ret[0] = '\0';
+      return ret;
+    }
+
+  slen = strlen (string);
+  retsize = 3 * slen + 1;
+
+  ret = (char *)malloc (retsize);
+  if (ret == 0)
+    return 0;
+
+  retind = 0;
+  sind = 0;
+
+  while (string[sind])
+    sind = sh_charvis (string, &sind, slen, ret, &retind);
+
+  ret[retind] = '\0';
+  return ret;
+}