1 files changed, 126 insertions, 0 deletions
diff --git a/include/carefulputc.h b/include/carefulputc.h
new file mode 100644
index 0000000..3cc6f7f
--- /dev/null
+++ b/include/carefulputc.h
@@ -0,0 +1,126 @@
+#ifndef UTIL_LINUX_CAREFULPUTC_H
+#define UTIL_LINUX_CAREFULPUTC_H
+
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#ifdef HAVE_WIDECHAR
+#include <wctype.h>
+#include <wchar.h>
+#endif
+#include <stdbool.h>
+
+#include "cctype.h"
+
+/*
+ * A puts() for use in write and wall (that sometimes are sgid tty).
+ * It avoids control and invalid characters.
+ * The locale of the recipient is nominally unknown,
+ * but it's a solid bet that it's compatible with the author's.
+ * Use soft_width=0 to disable wrapping.
+ */
+static inline int fputs_careful(const char * s, FILE *fp, const char ctrl, bool cr_lf, int soft_width)
+{
+	int ret = 0, col = 0;
+
+	for (size_t slen = strlen(s); *s; ++s, --slen) {
+		if (*s == '\t')
+			col += (7 - (col % 8)) - 1;
+		else if (*s == '\r')
+			col = -1;
+		else if (*s == '\a')
+			--col;
+
+		if ((soft_width && col >= soft_width) || *s == '\n') {
+			if (soft_width) {
+				fprintf(fp, "%*s", soft_width - col, "");
+				col = 0;
+			}
+			ret = fputs(cr_lf ? "\r\n" : "\n", fp);
+			if (*s == '\n' || ret < 0)
+				goto wrote;
+		}
+
+		if (isprint(*s) || *s == '\a' || *s == '\t' || *s == '\r') {
+			ret = putc(*s, fp);
+			++col;
+		} else if (!c_isascii(*s)) {
+#ifdef HAVE_WIDECHAR
+			wchar_t w;
+			size_t clen = mbtowc(&w, s, slen);
+			switch(clen) {
+				case (size_t)-2:  // incomplete
+				case (size_t)-1:  // EILSEQ
+					mbtowc(NULL, NULL, 0);
+				nonprint:
+					col += ret = fprintf(fp, "\\%3hho", *s);
+					break;
+				default:
+					if(!iswprint(w))
+						goto nonprint;
+					ret = fwrite(s, 1, clen, fp);
+					if (soft_width)
+						col += wcwidth(w);
+					s += clen - 1;
+					slen -= clen - 1;
+					break;
+			}
+#else
+			col += ret = fprintf(fp, "\\%3hho", *s);
+#endif
+		} else {
+			ret = fputs((char[]){ ctrl, *s ^ 0x40, '\0' }, fp);
+			col += 2;
+		}
+
+	wrote:
+		if (ret < 0)
+			return EOF;
+	}
+	return 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  */