1 files changed, 74 insertions, 0 deletions
diff --git a/include/carefulputc.h b/include/carefulputc.h
new file mode 100644
index 0000000..8860b12
--- /dev/null
+++ b/include/carefulputc.h
@@ -0,0 +1,74 @@
+#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;
+}
+
+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)
+
+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  */