Fix the \x escape sequence to be limited to max 2 characters, instead of

consuming as long as there are isxdigit(3) characters available.

While here document it and mark it as an extension.

OK millert@

diff --git a/usr.bin/printf/printf.1 b/usr.bin/printf/printf.1
index 73ea464..37e2697 100644 (file)
--- a/usr.bin/printf/printf.1
+++ b/usr.bin/printf/printf.1
@@ -1,4 +1,4 @@
-.\"    $OpenBSD: printf.1,v 1.34 2020/01/16 16:46:47 schwarze Exp $
+.\"    $OpenBSD: printf.1,v 1.35 2021/05/07 14:31:27 martijn Exp $
 .\"
 .\" Copyright (c) 1989, 1990 The Regents of the University of California.
 .\" All rights reserved.
@@ -32,7 +32,7 @@
 .\"
 .\"    from: @(#)printf.1      5.11 (Berkeley) 7/24/91
 .\"
-.Dd $Mdocdate: January 16 2020 $
+.Dd $Mdocdate: May 7 2021 $
 .Dt PRINTF 1
 .Os
 .Sh NAME
@@ -103,6 +103,11 @@ Write a backslash character.
 Write an 8-bit character whose ASCII value is
 the 1-, 2-, or 3-digit octal number
 .Ar num .
+.It Cm \ex Ns Ar num
+Write an 8-bit character whose ASCII value is
+the 1- or 2-digit hexadecimal
+number
+.Ar num .
 .El
 .Pp
 Each format specification is introduced by the percent
@@ -383,7 +388,8 @@ and always operates as if
 were set.
 .Pp
 The escape sequences
-.Cm \ee
+.Cm \ee ,
+.Cm \ex
 and
 .Cm \e' ,
 as well as omitting the leading digit

diff --git a/usr.bin/printf/printf.c b/usr.bin/printf/printf.c
index 30feac0..ecbf4ba 100644 (file)
--- a/usr.bin/printf/printf.c
+++ b/usr.bin/printf/printf.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: printf.c,v 1.26 2016/11/18 15:53:16 schwarze Exp $    */
+/*     $OpenBSD: printf.c,v 1.27 2021/05/07 14:31:27 martijn Exp $     */
 
 /*
  * Copyright (c) 1989 The Regents of the University of California.
@@ -275,7 +275,7 @@ static int
 print_escape(const char *str)
 {
        const char *start = str;
-       int value;
+       int value = 0;
        int c;
 
        str++;
@@ -283,7 +283,7 @@ print_escape(const char *str)
        switch (*str) {
        case '0': case '1': case '2': case '3':
        case '4': case '5': case '6': case '7':
-               for (c = 3, value = 0; c-- && isodigit(*str); str++) {
+               for (c = 3; c-- && isodigit(*str); str++) {
                        value <<= 3;
                        value += octtobin(*str);
                }
@@ -293,14 +293,10 @@ print_escape(const char *str)
 
        case 'x':
                str++;
-               for (value = 0; isxdigit((unsigned char)*str); str++) {
+               for (c = 2; c-- && isxdigit((unsigned char)*str); str++) {
                        value <<= 4;
                        value += hextobin(*str);
                }
-               if (value > UCHAR_MAX) {
-                       warnx ("escape sequence out of range for character");
-                       rval = 1;
-               }
                putchar (value);
                return str - start - 1;
                /* NOTREACHED */