hexdump: fix numerous bugs in handling of backslashes

Was:
	t=48\\	t=45\\	t=4c\\	t=4c\\	t=4f\\	t=0a\\
Now:
	=48=\n	=45=\n	=4c=\n	=4c=\n	=4f=\n	=0a=\n

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/libbb/dump.c b/libbb/dump.c
index 566881a781fd9356a4bd851b0bfa4d337e615512..154be5d809db5b25c16fc1634ee5207a18ed2003 100644 (file)
--- a/libbb/dump.c
+++ b/libbb/dump.c
@@ -157,7 +157,7 @@ static NOINLINE void rewrite(priv_dumper_t *dumper, FS *fs)
                        /*
                         * figure out the byte count for each conversion;
                         * rewrite the format as necessary, set up blank-
-                        * pbb_dump_adding for end of data.
+                        * padding for end of data.
                         */
                        if (*p1 == 'c') {
                                pr->flags = F_CHAR;
@@ -466,14 +466,14 @@ static void bpad(PR *pr)
 }
 
 static const char conv_str[] ALIGN1 =
-       "\0\\0\0"
-       "\007\\a\0"  /* \a */
-       "\b\\b\0"
-       "\f\\b\0"
-       "\n\\n\0"
-       "\r\\r\0"
-       "\t\\t\0"
-       "\v\\v\0"
+       "\0"  "\\""0""\0"
+       "\007""\\""a""\0"  /* \a */
+       "\b"  "\\""b""\0"
+       "\f"  "\\""f""\0"
+       "\n"  "\\""n""\0"
+       "\r"  "\\""r""\0"
+       "\t"  "\\""t""\0"
+       "\v"  "\\""v""\0"
        ;
 
 
@@ -485,7 +485,7 @@ static void conv_c(PR *pr, unsigned char *p)
        do {
                if (*p == *str) {
                        ++str;
-                       goto strpr;
+                       goto strpr; /* map e.g. '\n' to "\\n" */
                }
                str += 4;
        } while (*str);
@@ -702,8 +702,6 @@ int FAST_FUNC bb_dump_dump(dumper_t *pub_dumper, char **argv)
 void FAST_FUNC bb_dump_add(dumper_t* pub_dumper, const char *fmt)
 {
        const char *p;
-       char *p1;
-       char *p2;
        FS *tfs;
        FU *tfu, **nextfupp;
        const char *savep;
@@ -779,29 +777,42 @@ void FAST_FUNC bb_dump_add(dumper_t* pub_dumper, const char *fmt)
                        }
                }
                tfu->fmt = xstrndup(savep, p - savep);
-/*      escape(tfu->fmt); */
-
-               p1 = tfu->fmt;
 
                /* alphabetic escape sequences have to be done in place */
+               strcpy_and_process_escape_sequences(tfu->fmt, tfu->fmt);
+               /* unknown mappings are not changed: "\z" -> '\\' 'z' */
+               /* trailing backslash, if any, is preserved */
+#if 0
+               char *p1;
+               char *p2;
+               p1 = tfu->fmt;
                for (p2 = p1;; ++p1, ++p2) {
-                       if (*p1 == '\0') {
-                               *p2 = *p1;
+                       *p2 = *p1;
+                       if (*p1 == '\0')
                                break;
-                       }
+
                        if (*p1 == '\\') {
-                               const char *cs = conv_str + 4;
-                               ++p1;
+                               const char *cs;
+
+                               p1++;
                                *p2 = *p1;
+                               if (*p1 == '\0') {
+                                       /* "...\" trailing backslash. Eaten. */
+                                       break;
+                               }
+                               cs = conv_str + 4; /* skip NUL element */
                                do {
+                                       /* map e.g. "\n" -> '\n' */
                                        if (*p1 == cs[2]) {
                                                *p2 = cs[0];
                                                break;
                                        }
                                        cs += 4;
                                } while (*cs);
+                               /* unknown mappings remove bkslash: "\z" -> 'z' */
                        }
                }
+#endif
 
                p++;
        }