1 files changed, 310 insertions, 0 deletions
diff --git a/src/pstring.c b/src/pstring.c
new file mode 100644
index 0000000..ef845f3
--- /dev/null
+++ b/src/pstring.c
@@ -0,0 +1,310 @@
+/*--------------------------------------------------------------------
+ * Copyright © 2012-2016 James Hunt <jamesodhunt@ubuntu.com>.
+ *
+ * This program 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.
+ *
+ * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+ *--------------------------------------------------------------------
+ */
+
+#include "pstring.h"
+
+#include <assert.h>
+
+extern wchar_t wide_indent_char;
+
+wchar_t *
+char_to_wchar (const char *str)
+{
+	const char  *p;
+	wchar_t     *wstr = NULL;
+	size_t       len;
+	size_t       bytes;
+
+	assert (str);
+
+	len = mbsrtowcs (NULL, &str, 0, NULL);
+	if (len <= 0)
+		return NULL;
+
+	/* include space for terminator */
+	bytes = (1 + len) * sizeof (wchar_t);
+
+	wstr = malloc (bytes);
+	if (! wstr)
+		return NULL;
+
+	p = str;
+
+	if (mbsrtowcs (wstr, &p, len, NULL) != len)
+		goto error;
+
+	/* ensure it's terminated */
+	wstr[len] = L'\0';
+
+	return wstr;
+
+error:
+	free (wstr);
+	return NULL;
+}
+
+char *
+wchar_to_char (const wchar_t *wstr)
+{
+	char    *str = NULL;
+	size_t   len;
+	size_t   bytes;
+	size_t   ret;
+
+	assert (wstr);
+
+	len = wcslen (wstr);
+
+	/* determine number of MBS (char) bytes requires to hold the
+	 * wchar_t string.
+	 */
+	bytes = wcstombs (NULL, wstr, len);
+	if (! bytes)
+		return NULL;
+
+	str = calloc (bytes + 1, sizeof (char));
+	if (! str)
+		return NULL;
+
+	/* actually perform the conversion */
+	ret = wcstombs (str, wstr, bytes);
+
+	if (! ret)
+		goto error;
+
+	return str;
+
+error:
+	free (str);
+	return NULL;
+}
+
+pstring *
+pstring_new (void)
+{
+	pstring *pstr = NULL;
+
+	pstr = calloc (1, sizeof (pstring));
+	if (! pstr)
+		return NULL;
+
+	pstr->len = 0;
+	pstr->size = 0;
+	pstr->buf = NULL;
+
+	return pstr;
+}
+
+pstring *
+pstring_create (const wchar_t *str)
+{
+	pstring *pstr = NULL;
+
+	assert (str);
+
+	pstr = pstring_new ();
+
+	if (! pstr)
+		return NULL;
+
+	pstr->buf = wcsdup (str);
+	if (! pstr->buf) {
+		pstring_free (pstr);
+		return NULL;
+	}
+
+	/* include the L'\0' terminator */
+	pstr->len = 1 + wcslen (pstr->buf);
+
+	pstr->size = pstr->len * sizeof (wchar_t);
+
+	return pstr;
+}
+
+void
+pstring_free (pstring *str)
+{
+	assert (str);
+
+	if (str->buf)
+		free (str->buf);
+
+	free (str);
+}
+
+pstring *
+char_to_pstring (const char *str)
+{
+	pstring  *pstr = NULL;
+	wchar_t  *s;
+
+	assert (str);
+
+	s = char_to_wchar (str);
+	if (! s)
+		return NULL;
+
+	pstr = pstring_create (s);
+
+	free (s);
+
+	return pstr;
+}
+
+char *
+pstring_to_char (const pstring *str)
+{
+	assert (str);
+
+	return wchar_to_char (str->buf);
+}
+
+/**
+ * pstring_chomp:
+ *
+ * Remove trailing extraneous newlines and indent_chars from @str.
+ **/
+void
+pstring_chomp (pstring *str)
+{
+	size_t    len;
+	int       removable = 0;
+	wchar_t  *p;
+
+	assert (str);
+
+	/* Unable to add '\n' in this scenario */
+	if (str->len < 2)
+		return;
+
+	for (p = str->buf+str->len-1;
+            *p == L'\n' || *p == wide_indent_char;
+			p--, removable++)
+		;
+
+	/* Chop string at the appropriate place after first adding a new
+	 * newline.
+	 */
+	if (removable > 1) {
+		len = str->len - (removable-1);
+		str->buf[len-1] = L'\n';
+		str->buf[len] = L'\0';
+		str->len = len;
+	}
+}
+
+/**
+ * pstring_compress:
+ *
+ * Remove lines composed entirely of whitespace from @str.
+ *
+ * This is required specifically for '--output=text' which in some
+ * scenarios generates lines comprising pure whitespace. This is
+ * unecessary and results from the fact that when an
+ * ELEMENT_TYPE_OBJECT_* is encountered, formatting is applied for the
+ * previously seen element, but sometimes such "objects" should be
+ * invisible.
+ **/
+void
+pstring_compress (pstring **wstr, wchar_t remove_char)
+{
+	wchar_t  *from;
+	wchar_t  *to;
+	wchar_t  *p;
+	wchar_t  *start;
+	size_t    count = 0;
+	size_t    blanks = 0;
+	size_t    new_len;
+	size_t    bytes;
+
+	assert (wstr);
+
+	to = from = (*wstr)->buf;
+	assert (from);
+
+	while (to && *to) {
+again:
+		while (*to == L'\n' && *(to+1) == L'\n') {
+			/* skip over blank lines */
+			to++;
+			blanks++;
+		}
+
+		start = to;
+
+		while (*to == remove_char) {
+			/* skip runs of contiguous characters */
+			to++;
+			count++;
+		}
+
+		if (to != start) {
+			/* Only start consuming NLs at the end of a
+			 * contiguous run *iff* there was more than a
+			 * single removed char. This is a heuristic to
+			 * avoid removing valid entries for example env
+			 * vars that are set to nul are shown as:
+			 *
+			 *  'var: '
+			 *
+			 * Shudder.
+			 */
+			if (*to == L'\n' && to != start+1) {
+				while (*to == L'\n') {
+					/* consume the NL at the end of the contiguous run */
+					to++;
+				}
+
+				/* check to ensure that we haven't entered a new line
+				 * containing another block of chars to remove.
+				 */
+				if (*to == remove_char)
+					goto again;
+
+				blanks++;
+
+			} else  {
+				/* not a full line so backtrack */
+				to = start;
+				count = 0;
+			}
+		}
+
+		*from++ = *to++;
+	}
+
+	/* terminate */
+	*from = L'\0';
+
+	if (blanks || count) {
+		new_len = (*wstr)->len - (blanks + count);
+
+		bytes = new_len * sizeof (wchar_t);
+
+		p = realloc ((*wstr)->buf, bytes);
+		assert (p);
+
+		(*wstr)->buf = p;
+
+		(*wstr)->buf[new_len-1] = L'\0';
+
+		(*wstr)->len = new_len;
+		(*wstr)->size = bytes;
+	}
+}
+