adding libbb/printable.c

1 files changed, 34 insertions, 0 deletions

diff --git a/libbb/printable.c b/libbb/printable.c
new file mode 100644
index 000000000..2420a91f0
--- /dev/null
+++ b/libbb/printable.c
@@ -0,0 +1,34 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Utility routines.
+ *
+ * Copyright (C) 2007 Denis Vlasenko
+ *
+ * Licensed under GPL version 2, see file LICENSE in this tarball for details.
+ */
+
+#include "libbb.h"
+
+void fputc_printable(int ch, FILE *file)
+{
+        if ((ch & (0x80 + PRINTABLE_META)) == (0x80 + PRINTABLE_META)) {
+                fputs("M-", file);
+                ch &= 0x7f;
+        }
+        ch = (unsigned char) ch;
+        if (ch == 0x9b) {
+                /* VT100's CSI, aka Meta-ESC, is not printable on vt-100 */
+                ch = '{';
+                goto print_caret;
+        }
+        if (ch < ' ') {
+                ch += '@';
+                goto print_caret;
+        }
+        if (ch == 0x7f) {
+                ch = '?';
+ print_caret:
+                fputc('^', file);
+        }
+        fputc(ch, file);
+}