Refactor catv. Move visible() from stty to libbb.

Fixes the following TODO:

  stty's visible() function and catv's guts are identical. Merge them into
  an appropriate libbb function.

Also makes catv behave exactly like coreutils' cat -v e.g. it'll print 'M-^I'
instead of 'M-   '.

function                                             old     new   delta
visible                                                -      70     +70
do_display                                           431     379     -52
catv_main                                            306     250     -56
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/2 up/down: 70/-108)           Total: -38 bytes

Signed-off-by: Bartosz Golaszewski <bartekgola@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 16 insertions, 22 deletions

diff --git a/coreutils/catv.c b/coreutils/catv.c
index 214b4311a..18b18104e 100644
--- a/coreutils/catv.c
+++ b/coreutils/catv.c
@@ -25,14 +25,20 @@ int catv_main(int argc UNUSED_PARAM, char **argv)
 {
         int retval = EXIT_SUCCESS;
         int fd;
-        unsigned flags;
+        unsigned opts;
+        int flags = 0;
 
-        flags = getopt32(argv, "etv");
+        opts = getopt32(argv, "etv");
 #define CATV_OPT_e (1<<0)
 #define CATV_OPT_t (1<<1)
 #define CATV_OPT_v (1<<2)
-        flags ^= CATV_OPT_v;
         argv += optind;
+        if (opts & (CATV_OPT_e | CATV_OPT_t))
+                opts &= ~CATV_OPT_v;
+        if (opts & CATV_OPT_e)
+                flags |= VISIBLE_ENDLINE;
+        if (opts & CATV_OPT_t)
+                flags |= VISIBLE_SHOW_TABS;
 
         /* Read from stdin if there's nothing else to do. */
         if (!argv[0])
@@ -50,29 +56,17 @@ int catv_main(int argc UNUSED_PARAM, char **argv)
                         res = read(fd, read_buf, COMMON_BUFSIZE);
                         if (res < 0)
                                 retval = EXIT_FAILURE;
-                        if (res < 1)
+                        if (res <= 0)
                                 break;
                         for (i = 0; i < res; i++) {
                                 unsigned char c = read_buf[i];
-
-                                if (c > 126 && (flags & CATV_OPT_v)) {
-                                        if (c == 127) {
-                                                printf("^?");
-                                                continue;
-                                        }
-                                        printf("M-");
-                                        c -= 128;
-                                }
-                                if (c < 32) {
-                                        if (c == 10) {
-                                                if (flags & CATV_OPT_e)
-                                                        bb_putchar('$');
-                                        } else if (flags & (c==9 ? CATV_OPT_t : CATV_OPT_v)) {
-                                                printf("^%c", c+'@');
-                                                continue;
-                                        }
+                                if (opts & CATV_OPT_v) {
+                                        putchar(c);
+                                } else {
+                                        char buf[sizeof("M-^c")];
+                                        visible(c, buf, flags);
+                                        fputs(buf, stdout);
                                 }
-                                bb_putchar(c);
                         }
                 }
                 if (ENABLE_FEATURE_CLEAN_UP && fd)