hush: HUSH_READONLY depends on HUSH

[oweals/busybox.git] / libbb / process_escape_sequence.c

diff --git a/libbb/process_escape_sequence.c b/libbb/process_escape_sequence.c
index dd6e076b0cb0c8102897e45117087ebb2ce0a12f..346ecfa1e2c0c5de4bc299ee10c12d4c465ce685 100644 (file)
--- a/libbb/process_escape_sequence.c
+++ b/libbb/process_escape_sequence.c
@@ -18,18 +18,8 @@
 
 char FAST_FUNC bb_process_escape_sequence(const char **ptr)
 {
-       /* bash builtin "echo -e '\ec'" interprets \e as ESC,
-        * but coreutils "/bin/echo -e '\ec'" does not.
-        * manpages tend to support coreutils way.
-        * Update: coreutils added support for \e on 28 Oct 2009. */
-       static const char charmap[] ALIGN1 = {
-               'a',  'b', 'e', 'f',  'n',  'r',  't',  'v',  '\\', 0,
-               '\a', '\b', 27, '\f', '\n', '\r', '\t', '\v', '\\', '\\' };
-
-       const char *p;
        const char *q;
        unsigned num_digits;
-       unsigned r;
        unsigned n;
        unsigned base;
 
@@ -37,18 +27,17 @@ char FAST_FUNC bb_process_escape_sequence(const char **ptr)
        base = 8;
        q = *ptr;
 
-#if WANT_HEX_ESCAPES
-       if (*q == 'x') {
+       if (WANT_HEX_ESCAPES && *q == 'x') {
                ++q;
                base = 16;
                ++num_digits;
        }
-#endif
 
        /* bash requires leading 0 in octal escapes:
         * \02 works, \2 does not (prints \ and 2).
         * We treat \2 as a valid octal escape sequence. */
        do {
+               unsigned r;
 #if !WANT_HEX_ESCAPES
                unsigned d = (unsigned char)(*q) - '0';
 #else
@@ -60,8 +49,9 @@ char FAST_FUNC bb_process_escape_sequence(const char **ptr)
                        if (WANT_HEX_ESCAPES && base == 16) {
                                --num_digits;
                                if (num_digits == 0) {
-                                       /* \x<bad_char> */
-                                       --q; /* go back to x */
+                                       /* \x<bad_char>: return '\',
+                                        * leave ptr pointing to x */
+                                       return '\\';
                                }
                        }
                        break;
@@ -76,20 +66,30 @@ char FAST_FUNC bb_process_escape_sequence(const char **ptr)
                ++q;
        } while (++num_digits < 3);
 
-       if (num_digits == 0) {  /* mnemonic escape sequence? */
-               p = charmap;
+       if (num_digits == 0) {
+               /* Not octal or hex escape sequence.
+                * Is it one-letter one? */
+
+               /* bash builtin "echo -e '\ec'" interprets \e as ESC,
+                * but coreutils "/bin/echo -e '\ec'" does not.
+                * Manpages tend to support coreutils way.
+                * Update: coreutils added support for \e on 28 Oct 2009. */
+               static const char charmap[] ALIGN1 = {
+                       'a',  'b', 'e', 'f',  'n',  'r',  't',  'v',  '\\', '\0',
+                       '\a', '\b', 27, '\f', '\n', '\r', '\t', '\v', '\\', '\\',
+               };
+               const char *p = charmap;
                do {
                        if (*p == *q) {
                                q++;
                                break;
                        }
-               } while (*++p);
+               } while (*++p != '\0');
                /* p points to found escape char or NUL,
                 * advance it and find what it translates to.
-                * Note that unrecognized sequence \z returns '\'
-                * and leaves ptr pointing to z. */
-               p += sizeof(charmap) / 2;
-               n = *p;
+                * Note that \NUL and unrecognized sequence \z return '\'
+                * and leave ptr pointing to NUL or z. */
+               n = p[sizeof(charmap) / 2];
        }
 
        *ptr = q;