2 files changed, 73 insertions, 64 deletions

diff --git a/util-linux/hexdump.c b/util-linux/hexdump.c
index 065b83980..2174c3008 100644
--- a/util-linux/hexdump.c
+++ b/util-linux/hexdump.c
@@ -15,16 +15,6 @@
 //config:       The hexdump utility is used to display binary data in a readable
 //config:       way that is comparable to the output from most hex editors.
 //config:
-//config:config FEATURE_HEXDUMP_REVERSE
-//config:       bool "Support -R, reverse of 'hexdump -Cv'"
-//config:       default y
-//config:       depends on HEXDUMP
-//config:       help
-//config:       The hexdump utility is used to display binary data in an ascii
-//config:       readable way. This option creates binary data from an ascii input.
-//config:       NB: this option is non-standard. It's unwise to use it in scripts
-//config:       aimed to be portable.
-//config:
 //config:config HD
 //config:       bool "hd (7.8 kb)"
 //config:       default y
@@ -38,7 +28,7 @@
 //kbuild:lib-$(CONFIG_HD) += hexdump.o
 
 //usage:#define hexdump_trivial_usage
-//usage:       "[-bcCdefnosvx" IF_FEATURE_HEXDUMP_REVERSE("R") "] [FILE]..."
+//usage:       "[-bcCdefnosvx] [FILE]..."
 //usage:#define hexdump_full_usage "\n\n"
 //usage:       "Display FILEs (or stdin) in a user specified format\n"
 //usage:     "\n        -b              1-byte octal display"
@@ -53,9 +43,6 @@
 // exactly the same help text lines in hexdump and xxd:
 //usage:     "\n        -n LENGTH       Show only first LENGTH bytes"
 //usage:     "\n        -s OFFSET       Skip OFFSET bytes"
-//usage:        IF_FEATURE_HEXDUMP_REVERSE(
-//usage:     "\n        -R              Reverse of 'hexdump -Cv'")
-// TODO: NONCOMPAT!!! move -R to xxd -r
 //usage:
 //usage:#define hd_trivial_usage
 //usage:       "FILE..."
@@ -94,7 +81,7 @@ static const char *const add_strings[] = {
 
 static const char add_first[] ALIGN1 = "\"%07.7_Ax\n\"";
 
-static const char hexdump_opts[] ALIGN1 = "bcdoxCe:f:n:s:v" IF_FEATURE_HEXDUMP_REVERSE("R");
+static const char hexdump_opts[] ALIGN1 = "bcdoxCe:f:n:s:v";
 
 int hexdump_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int hexdump_main(int argc, char **argv)
@@ -102,10 +89,6 @@ int hexdump_main(int argc, char **argv)
         dumper_t *dumper = alloc_dumper();
         const char *p;
         int ch;
-#if ENABLE_FEATURE_HEXDUMP_REVERSE
-        FILE *fp;
-        smallint rdump = 0;
-#endif
 
         if (ENABLE_HD
          && (!ENABLE_HEXDUMP || !applet_name[2])
@@ -153,11 +136,6 @@ int hexdump_main(int argc, char **argv)
                 if (ch == 'v') {
                         dumper->dump_vflag = ALL;
                 }
-#if ENABLE_FEATURE_HEXDUMP_REVERSE
-                if (ch == 'R') {
-                        rdump = 1;
-                }
-#endif
         }
 
         if (!dumper->fshead) {
@@ -167,40 +145,5 @@ int hexdump_main(int argc, char **argv)
 
         argv += optind;
 
-#if !ENABLE_FEATURE_HEXDUMP_REVERSE
         return bb_dump_dump(dumper, argv);
-#else
-        if (!rdump) {
-                return bb_dump_dump(dumper, argv);
-        }
-
-        /* -R: reverse of 'hexdump -Cv' */
-        fp = stdin;
-        if (!*argv) {
-                argv--;
-                goto jump_in;
-        }
-
-        do {
-                char *buf;
-                fp = xfopen_for_read(*argv);
- jump_in:
-                while ((buf = xmalloc_fgetline(fp)) != NULL) {
-                        p = buf;
-                        while (1) {
-                                /* skip address or previous byte */
-                                while (isxdigit(*p)) p++;
-                                while (*p == ' ') p++;
-                                /* '|' char will break the line */
-                                if (!isxdigit(*p) || sscanf(p, "%x ", &ch) != 1)
-                                        break;
-                                putchar(ch);
-                        }
-                        free(buf);
-                }
-                fclose(fp);
-        } while (*++argv);
-
-        fflush_stdout_and_exit(EXIT_SUCCESS);
-#endif
 }
diff --git a/util-linux/hexdump_xxd.c b/util-linux/hexdump_xxd.c
index f2d1ecb2c..d2f4b6ed8 100644
--- a/util-linux/hexdump_xxd.c
+++ b/util-linux/hexdump_xxd.c
@@ -50,6 +50,7 @@
 // exactly the same help text lines in hexdump and xxd:
 //usage:     "\n        -l LENGTH       Show only first LENGTH bytes"
 //usage:     "\n        -s OFFSET       Skip OFFSET bytes"
+//usage:     "\n        -r              Reverse (with -p, assumes no offsets in input)"
 // TODO: implement -r (see hexdump -R)
 
 #include "libbb.h"
@@ -57,6 +58,71 @@
 
 /* This is a NOEXEC applet. Be very careful! */
 
+#define OPT_l (1 << 0)
+#define OPT_s (1 << 1)
+#define OPT_a (1 << 2)
+#define OPT_p (1 << 3)
+#define OPT_r (1 << 4)
+
+static void reverse(unsigned opt, unsigned cols, const char *filename)
+{
+        FILE *fp;
+        char *buf;
+
+        fp = filename ? xfopen_for_read(filename) : stdin;
+
+        while ((buf = xmalloc_fgetline(fp)) != NULL) {
+                char *p = buf;
+                unsigned cnt = cols;
+
+                if (!(opt & OPT_p)) {
+                        /* skip address */
+                        while (isxdigit(*p)) p++;
+                        /* NB: for xxd -r, first hex portion is address even without colon */
+                        /* If it's there, skip it: */
+                        if (*p == ':') p++;
+
+//TODO: seek (or zero-pad if unseekable) to the address position
+//NOTE: -s SEEK value should be added to the address before seeking
+                }
+
+                /* Process hex bytes optionally separated by whitespace */
+                do {
+                        uint8_t val, c;
+
+                        p = skip_whitespace(p);
+
+                        c = *p++;
+                        if (isdigit(c))
+                                val = c - '0';
+                        else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
+                                val = (c|0x20) - ('a' - 10);
+                        else
+                                break;
+                        val <<= 4;
+
+                        /* Works the same with xxd V1.10:
+                         *  echo "31 09 32 0a" | xxd -r -p
+                         *  echo "31 0 9 32 0a" | xxd -r -p
+                         * thus allow whitespace even within the byte:
+                         */
+                        p = skip_whitespace(p);
+
+                        c = *p++;
+                        if (isdigit(c))
+                                val |= c - '0';
+                        else if ((c|0x20) >= 'a' && (c|0x20) <= 'f')
+                                val |= (c|0x20) - ('a' - 10);
+                        else
+                                break;
+                        putchar(val);
+                } while (!(opt & OPT_p) || --cnt != 0);
+                free(buf);
+        }
+        //fclose(fp);
+        fflush_stdout_and_exit(EXIT_SUCCESS);
+}
+
 int xxd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int xxd_main(int argc UNUSED_PARAM, char **argv)
 {
@@ -69,11 +135,7 @@ int xxd_main(int argc UNUSED_PARAM, char **argv)
 
         dumper = alloc_dumper();
 
-#define OPT_l (1 << 0)
-#define OPT_s (1 << 1)
-#define OPT_a (1 << 2)
-#define OPT_p (1 << 3)
-        opt = getopt32(argv, "^" "l:s:apg:+c:+" "\0" "?1" /* 1 argument max */,
+        opt = getopt32(argv, "^" "l:s:aprg:+c:+" "\0" "?1" /* 1 argument max */,
                         &opt_l, &opt_s, &bytes, &cols
         );
         argv += optind;
@@ -107,6 +169,10 @@ int xxd_main(int argc UNUSED_PARAM, char **argv)
                 bb_dump_add(dumper, "\"%08.8_ax: \""); // "address: "
         }
 
+        if (opt & OPT_r) {
+                reverse(opt, cols, argv[0]);
+        }
+
         if (bytes < 1 || bytes >= cols) {
                 sprintf(buf, "%u/1 \"%%02x\"", cols); // cols * "xx"
                 bb_dump_add(dumper, buf);