X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=string.c;h=e731bb496b4b0d0f2f5a7dac417cbbeab7b9f3f6;hp=d9dcc62d2ea45efc6a3c2899185a2033d5e74339;hb=8daabd03bb649ae04d6b2dd9e46640ca1e514d3d;hpb=5971e3303cf800603622c2475e07fdccc33e4915

diff --git a/string.c b/string.c
index d9dcc62d..e731bb49 100644
--- a/string.c
+++ b/string.c
@@ -1070,3 +1070,66 @@ __must_check int strwidth(const char *s, size_t *result)
 	free(dest);
 	return 1;
 }
+
+/**
+ * Truncate and sanitize a (wide character) string.
+ *
+ * This replaces all non-printable characters by spaces and makes sure that the
+ * modified string does not exceed the given maximal width.
+ *
+ * \param src The source string in multi-byte form.
+ * \param max_width The maximal number of cells the result may occupy.
+ * \param result Sanitized multi-byte string, must be freed by caller.
+ * \param width The width of the sanitized string, always <= max_width.
+ *
+ * The function is wide-character aware but falls back to C strings for
+ * non-UTF-8 locales.
+ *
+ * \return Standard. On success, *result points to a sanitized copy of the
+ * given string. This copy was allocated with malloc() and should hence be
+ * freed when the caller is no longer interested in the result.
+ *
+ * The function fails if the given string contains an invalid multibyte
+ * sequence. In this case, *result is set to NULL, and *width to zero.
+ */
+__must_check int sanitize_str(const char *src, size_t max_width,
+		char **result, size_t *width)
+{
+	mbstate_t state;
+	static wchar_t *wcs;
+	size_t num_wchars, n;
+
+	if (!utf8_mode()) {
+		*result = para_strdup(src);
+		/* replace non-printable characters by spaces */
+		for (n = 0; n < max_width && src[n]; n++) {
+			if (!isprint((unsigned char)src[n]))
+				(*result)[n] = ' ';
+		}
+		(*result)[n] = '\0';
+		*width = n;
+		return 0;
+	}
+	*result = NULL;
+	*width = 0;
+	memset(&state, 0, sizeof(state));
+	num_wchars = mbsrtowcs(NULL, &src, 0, &state);
+	if (num_wchars == (size_t)-1)
+		return -ERRNO_TO_PARA_ERROR(errno);
+	wcs = para_malloc((num_wchars + 1) * sizeof(*wcs));
+	memset(&state, 0, sizeof(state));
+	num_wchars = mbsrtowcs(wcs, &src, num_wchars + 1, &state);
+	assert(num_wchars != (size_t)-1);
+	for (n = 0; n < num_wchars && *width < max_width; n++) {
+		if (!iswprint(wcs[n]))
+			wcs[n] = L' ';
+		*width += xwcwidth(wcs[n], *width);
+	}
+	wcs[n] = L'\0';
+	n = wcstombs(NULL, wcs, 0) + 1;
+	*result = para_malloc(n);
+	num_wchars = wcstombs(*result, wcs, n);
+	assert(num_wchars != (size_t)-1);
+	free(wcs);
+	return 1;
+}