1 files changed, 155 insertions, 0 deletions
diff --git a/src/utils/include/carefulputc.h b/src/utils/include/carefulputc.h
new file mode 100644
index 0000000..f1c0356
--- /dev/null
+++ b/src/utils/include/carefulputc.h
@@ -0,0 +1,155 @@
+#ifndef UTIL_LINUX_CAREFULPUTC_H
+#define UTIL_LINUX_CAREFULPUTC_H
+
+/*
+ * A putc() for use in write and wall (that sometimes are sgid tty).
+ * It avoids control characters in our locale, and also ASCII control
+ * characters.   Note that the locale of the recipient is unknown.
+*/
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+
+#include "cctype.h"
+
+static inline int fputc_careful(int c, FILE *fp, const char fail)
+{
+	int ret;
+
+	if (isprint(c) || c == '\a' || c == '\t' || c == '\r' || c == '\n')
+		ret = putc(c, fp);
+	else if (!c_isascii(c))
+		ret = fprintf(fp, "\\%3o", (unsigned char)c);
+	else {
+		ret = putc(fail, fp);
+		if (ret != EOF)
+			ret = putc(c ^ 0x40, fp);
+	}
+	return (ret < 0) ? EOF : 0;
+}
+
+/*
+ * Requirements enumerated via testing (V8, Firefox, IE11):
+ *
+ * var charsToEscape = [];
+ * for (var i = 0; i < 65535; i += 1) {
+ *	try {
+ *		JSON.parse('{"sample": "' + String.fromCodePoint(i) + '"}');
+ *	} catch (e) {
+ *		charsToEscape.push(i);
+ *	}
+ * }
+ */
+static inline void fputs_quoted_case_json(const char *data, FILE *out, int dir)
+{
+	const char *p;
+
+	fputc('"', out);
+	for (p = data; p && *p; p++) {
+
+		const unsigned char c = (unsigned char) *p;
+
+		/* From http://www.json.org
+		 *
+		 * The double-quote and backslashes would break out a string or
+		 * init an escape sequence if not escaped.
+		 *
+		 * Note that single-quotes and forward slashes, while they're
+		 * in the JSON spec, don't break double-quoted strings.
+		 */
+		if (c == '"' || c == '\\') {
+			fputc('\\', out);
+			fputc(c, out);
+			continue;
+		}
+
+		/* All non-control characters OK; do the case swap as required. */
+		if (c >= 0x20) {
+			fputc(dir ==  1 ? toupper(c) :
+			      dir == -1 ? tolower(c) : *p, out);
+			continue;
+		}
+
+		/* In addition, all chars under ' ' break Node's/V8/Chrome's, and
+		 * Firefox's JSON.parse function
+		 */
+		switch (c) {
+			/* Handle short-hand cases to reduce output size.  C
+			 * has most of the same stuff here, so if there's an
+			 * "Escape for C" function somewhere in the STL, we
+			 * should probably be using it.
+			 */
+			case '\b':
+				fputs("\\b", out);
+				break;
+			case '\t':
+				fputs("\\t", out);
+				break;
+			case '\n':
+				fputs("\\n", out);
+				break;
+			case '\f':
+				fputs("\\f", out);
+				break;
+			case '\r':
+				fputs("\\r", out);
+				break;
+			default:
+				/* Other assorted control characters */
+				fprintf(out, "\\u00%02x", c);
+				break;
+		}
+	}
+	fputc('"', out);
+}
+
+
+static inline void fputs_quoted_case(const char *data, FILE *out, int dir)
+{
+	const char *p;
+
+	fputc('"', out);
+	for (p = data; p && *p; p++) {
+		if ((unsigned char) *p == 0x22 ||		/* " */
+		    (unsigned char) *p == 0x5c ||		/* \ */
+		    (unsigned char) *p == 0x60 ||		/* ` */
+		    (unsigned char) *p == 0x24 ||		/* $ */
+		    !isprint((unsigned char) *p) ||
+		    iscntrl((unsigned char) *p)) {
+
+			fprintf(out, "\\x%02x", (unsigned char) *p);
+		} else
+			fputc(dir ==  1 ? toupper(*p) :
+			      dir == -1 ? tolower(*p) :
+			      *p, out);
+	}
+	fputc('"', out);
+}
+
+#define fputs_quoted(_d, _o)		fputs_quoted_case(_d, _o, 0)
+#define fputs_quoted_upper(_d, _o)	fputs_quoted_case(_d, _o, 1)
+#define fputs_quoted_lower(_d, _o)	fputs_quoted_case(_d, _o, -1)
+
+#define fputs_quoted_json(_d, _o)       fputs_quoted_case_json(_d, _o, 0)
+#define fputs_quoted_json_upper(_d, _o) fputs_quoted_case_json(_d, _o, 1)
+#define fputs_quoted_json_lower(_d, _o) fputs_quoted_case_json(_d, _o, -1)
+
+static inline void fputs_nonblank(const char *data, FILE *out)
+{
+	const char *p;
+
+	for (p = data; p && *p; p++) {
+		if (isblank((unsigned char) *p) ||
+		    (unsigned char) *p == 0x5c ||		/* \ */
+		    !isprint((unsigned char) *p) ||
+		    iscntrl((unsigned char) *p)) {
+
+			fprintf(out, "\\x%02x", (unsigned char) *p);
+
+		} else
+			fputc(*p, out);
+	}
+}
+
+
+#endif  /*  _CAREFULPUTC_H  */