ls: implement -q, fix -w0, reduce startup time

function                                             old     new   delta
ls_main                                              598     660     +62
ls_longopts                                            -      47     +47
G_isatty                                               -      36     +36
print_name                                           102     134     +32
display_files                                        358     374     +16
.rodata                                           105829  105833      +4
vgetopt32                                           1330    1317     -13
static.ls_longopts                                    47       -     -47
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 4/1 up/down: 197/-60)           Total: 137 bytes

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

2 files changed, 122 insertions, 62 deletions

diff --git a/coreutils/ls.c b/coreutils/ls.c
index cc809b797..eaccd1a17 100644
--- a/coreutils/ls.c
+++ b/coreutils/ls.c
@@ -126,6 +126,8 @@
 //usage:     "\n        -F      Append indicator (one of */=@|) to names"
 //usage:        )
 //usage:     "\n        -l      Long format"
+////usage:     "\n      -g      Long format without group column"
+////TODO: support -G too ("suppress owner column", GNUism)
 //usage:     "\n        -i      List inode numbers"
 //usage:     "\n        -n      List numeric UIDs and GIDs instead of names"
 //usage:     "\n        -s      List allocated blocks"
@@ -159,6 +161,8 @@
 //usage:        IF_FEATURE_LS_WIDTH(
 //usage:     "\n        -w N    Format N columns wide"
 //usage:        )
+////usage:     "\n      -Q      Double-quote names"
+////usage:     "\n      -q      Replace unprintable chars with '?'"
 //usage:        IF_FEATURE_LS_COLOR(
 //usage:     "\n        --color[={always,never,auto}]"
 //usage:        )
@@ -196,27 +200,47 @@ SPLIT_SUBDIR    = 2,
 
 /* -Cadi1l  Std options, busybox always supports */
 /* -gnsxA   Std options, busybox always supports */
-/* -Q       GNU option, busybox always supports */
-/* -k       Std option, busybox always supports (by ignoring) */
-/*          It means "for -s, show sizes in kbytes" */
-/*          Seems to only affect "POSIXLY_CORRECT=1 ls -sk" */
-/*          since otherwise -s shows kbytes anyway */
+/* -Q       GNU option, busybox always supports:  */
+/*          -Q, --quote-name                     */
+/*          enclose entry names in double quotes */
 /* -LHRctur Std options, busybox optionally supports */
 /* -Fp      Std options, busybox optionally supports */
 /* -SXvhTw  GNU options, busybox optionally supports */
 /* -T WIDTH Ignored (we don't use tabs on output) */
 /* -Z       SELinux mandated option, busybox optionally supports */
+/* -q       Std option, busybox always supports: */
+/*      https://pubs.opengroup.org/onlinepubs/9699919799/utilities/ls.html: */
+/*      Force each instance of non-printable filename characters and        */
+/*      <tab> characters to be written as the <question-mark> ('?')         */
+/*      character. Implementations may provide this option by default       */
+/*      if the output is to a terminal device.                              */
+/* -k       Std option, busybox always supports (by ignoring) */
+/*          It means "for -s, show sizes in kbytes" */
+/*          Seems to only affect "POSIXLY_CORRECT=1 ls -sk" */
+/*          since otherwise -s shows kbytes anyway */
 #define ls_options \
-        "Cadi1lgnsxAk"       /* 12 opts, total 12 */ \
-        IF_FEATURE_LS_FILETYPES("Fp")    /* 2, 14 */ \
-        IF_FEATURE_LS_RECURSIVE("R")     /* 1, 15 */ \
-        IF_SELINUX("Z")                  /* 1, 16 */ \
-        "Q"                              /* 1, 17 */ \
-        IF_FEATURE_LS_TIMESTAMPS("ctu")  /* 3, 20 */ \
-        IF_FEATURE_LS_SORTFILES("SXrv")  /* 4, 24 */ \
-        IF_FEATURE_LS_FOLLOWLINKS("LH")  /* 2, 26 */ \
-        IF_FEATURE_HUMAN_READABLE("h")   /* 1, 27 */ \
-        IF_FEATURE_LS_WIDTH("T:w:")      /* 2, 29 */
+        "Cadi1lgnsxA"        /* 11 opts, total 11 */ \
+        IF_FEATURE_LS_FILETYPES("Fp")    /* 2, 13 */ \
+        IF_FEATURE_LS_RECURSIVE("R")     /* 1, 14 */ \
+        IF_SELINUX("Z")                  /* 1, 15 */ \
+        "Q"                              /* 1, 16 */ \
+        IF_FEATURE_LS_TIMESTAMPS("ctu")  /* 3, 19 */ \
+        IF_FEATURE_LS_SORTFILES("SXrv")  /* 4, 23 */ \
+        IF_FEATURE_LS_FOLLOWLINKS("LH")  /* 2, 25 */ \
+        IF_FEATURE_HUMAN_READABLE("h")   /* 1, 26 */ \
+        IF_FEATURE_LS_WIDTH("T:w:")      /* 2, 28 */ \
+        IF_LONG_OPTS("\xff")             /* 1, 29 */ \
+        IF_LONG_OPTS("\xfe")             /* 1, 30 */ \
+        IF_LONG_OPTS("\xfd")             /* 1, 31 */ \
+        "qk"                             /* 2, 33 */
+
+#if ENABLE_LONG_OPTS
+static const char ls_longopts[] ALIGN1 =
+        "full-time\0" No_argument "\xff"
+        "group-directories-first\0" No_argument "\xfe"
+        IF_FEATURE_LS_COLOR("color\0" Optional_argument "\xfd")
+;
+#endif
 
 enum {
         OPT_C = (1 << 0),
@@ -230,29 +254,31 @@ enum {
         OPT_s = (1 << 8),
         OPT_x = (1 << 9),
         OPT_A = (1 << 10),
-        //OPT_k = (1 << 11),
 
-        OPTBIT_F = 12,
-        OPTBIT_p, /* 13 */
+        OPTBIT_F = 11,
+        OPTBIT_p, /* 12 */
         OPTBIT_R = OPTBIT_F + 2 * ENABLE_FEATURE_LS_FILETYPES,
         OPTBIT_Z = OPTBIT_R + 1 * ENABLE_FEATURE_LS_RECURSIVE,
         OPTBIT_Q = OPTBIT_Z + 1 * ENABLE_SELINUX,
-        OPTBIT_c, /* 17 */
-        OPTBIT_t, /* 18 */
-        OPTBIT_u, /* 19 */
+        OPTBIT_c, /* 16 */
+        OPTBIT_t, /* 17 */
+        OPTBIT_u, /* 18 */
         OPTBIT_S = OPTBIT_c + 3 * ENABLE_FEATURE_LS_TIMESTAMPS,
-        OPTBIT_X, /* 21 */
-        OPTBIT_r, /* 22 */
-        OPTBIT_v, /* 23 */
+        OPTBIT_X, /* 20 */
+        OPTBIT_r, /* 21 */
+        OPTBIT_v, /* 22 */
         OPTBIT_L = OPTBIT_S + 4 * ENABLE_FEATURE_LS_SORTFILES,
-        OPTBIT_H, /* 25 */
+        OPTBIT_H, /* 24 */
         OPTBIT_h = OPTBIT_L + 2 * ENABLE_FEATURE_LS_FOLLOWLINKS,
         OPTBIT_T = OPTBIT_h + 1 * ENABLE_FEATURE_HUMAN_READABLE,
-        OPTBIT_w, /* 28 */
+        OPTBIT_w, /* 27 */
         OPTBIT_full_time = OPTBIT_T + 2 * ENABLE_FEATURE_LS_WIDTH,
         OPTBIT_dirs_first,
-        OPTBIT_color, /* 31 */
-        /* with long opts, we use all 32 bits */
+        OPTBIT_color, /* 30 */
+        OPTBIT_q = OPTBIT_color + 1, /* 31 */
+        OPTBIT_k = OPTBIT_q + 1, /* 32 */
+        /* with all options enabled, we use all 32 bits and even one extra bit! */
+        /* this works because -k is ignored, and getopt32 allows such "ignore" options past 31th bit */
 
         OPT_F = (1 << OPTBIT_F) * ENABLE_FEATURE_LS_FILETYPES,
         OPT_p = (1 << OPTBIT_p) * ENABLE_FEATURE_LS_FILETYPES,
@@ -274,6 +300,8 @@ enum {
         OPT_full_time  = (1 << OPTBIT_full_time ) * ENABLE_LONG_OPTS,
         OPT_dirs_first = (1 << OPTBIT_dirs_first) * ENABLE_LONG_OPTS,
         OPT_color      = (1 << OPTBIT_color     ) * ENABLE_FEATURE_LS_COLOR,
+        OPT_q = (1 << OPTBIT_q),
+        //-k is ignored: OPT_k = (1 << OPTBIT_k),
 };
 
 /*
@@ -327,6 +355,7 @@ struct globals {
 #endif
         smallint exit_code;
         smallint show_dirname;
+        smallint tty_out;
 #if ENABLE_FEATURE_LS_WIDTH
         unsigned terminal_width;
 # define G_terminal_width (G.terminal_width)
@@ -343,16 +372,21 @@ struct globals {
         setup_common_bufsiz(); \
         /* we have to zero it out because of NOEXEC */ \
         memset(&G, 0, sizeof(G)); \
-        IF_FEATURE_LS_WIDTH(G_terminal_width = TERMINAL_WIDTH;) \
+        IF_FEATURE_LS_WIDTH(G_terminal_width = ~0U;) \
         IF_FEATURE_LS_TIMESTAMPS(time(&G.current_time_t);) \
 } while (0)
 
 #define ESC "\033"
 
+static int G_isatty(void)
+{
+        if (!G.tty_out) /* not known yet? */
+                G.tty_out = isatty(STDOUT_FILENO) + 1;
+        return (G.tty_out == 2);
+}
 
 /*** Output code ***/
 
-
 /* FYI type values: 1:fifo 2:char 4:dir 6:blk 8:file 10:link 12:socket
  * (various wacky OSes: 13:Sun door 14:BSD whiteout 5:XENIX named file
  *  3/7:multiplexed char/block device)
@@ -420,6 +454,9 @@ static unsigned calc_name_len(const char *name)
         unsigned len;
         uni_stat_t uni_stat;
 
+        if (!(option_mask32 & OPT_q))
+                return strlen(name);
+
         // TODO: quote tab as \t, etc, if -Q
         name = printable_string2(&uni_stat, name);
 
@@ -449,6 +486,11 @@ static unsigned print_name(const char *name)
         unsigned len;
         uni_stat_t uni_stat;
 
+        if (!(option_mask32 & OPT_q)) {
+                fputs_stdout(name);
+                return strlen(name);
+        }
+
         // TODO: quote tab as \t, etc, if -Q
         name = printable_string2(&uni_stat, name);
 
@@ -646,7 +688,7 @@ static void display_files(struct dnode **dn, unsigned nfiles)
         unsigned i, ncols, nrows, row, nc;
         unsigned column;
         unsigned nexttab;
-        unsigned column_width = 0; /* used only by coulmnal output */
+        unsigned column_width = 0; /* used only by columnar output */
 
         if (option_mask32 & (OPT_l|OPT_1)) {
                 ncols = 1;
@@ -691,6 +733,11 @@ static void display_files(struct dnode **dn, unsigned nfiles)
                                 }
                                 nexttab = column + column_width;
                                 column += display_single(dn[i]);
+                        } else {
+                                /* if -w999999999, ncols can be very large */
+                                //bb_error_msg(" col:%u ncol:%u i:%i", nc, ncols, i); sleep1();
+                                /* without "break", we loop millions of times here */
+                                break;
                         }
                 }
                 putchar('\n');
@@ -1090,25 +1137,11 @@ int ls_main(int argc UNUSED_PARAM, char **argv)
         /* need to initialize since --color has _an optional_ argument */
         const char *color_opt = color_str; /* "always" */
 #endif
-#if ENABLE_LONG_OPTS
-        static const char ls_longopts[] ALIGN1 =
-                "full-time\0" No_argument "\xff"
-                "group-directories-first\0" No_argument "\xfe"
-                IF_FEATURE_LS_COLOR("color\0" Optional_argument "\xfd")
-        ;
-#endif
 
         INIT_G();
 
         init_unicode();
 
-#if ENABLE_FEATURE_LS_WIDTH
-        /* obtain the terminal width */
-        G_terminal_width = get_terminal_width(STDIN_FILENO);
-        /* go one less... */
-        G_terminal_width--;
-#endif
-
         /* process options */
         opt = getopt32long(argv, "^"
                 ls_options
@@ -1144,6 +1177,17 @@ int ls_main(int argc UNUSED_PARAM, char **argv)
         exit(0);
 #endif
 
+#if ENABLE_FEATURE_LS_WIDTH
+        if ((int)G_terminal_width < 0) {
+                /* obtain the terminal width */
+                G_terminal_width = get_terminal_width(STDIN_FILENO);
+                /* go one less... */
+                G_terminal_width--;
+        }
+        if (G_terminal_width == 0) /* -w0 */
+                G_terminal_width = INT_MAX; /* "infinite" */
+#endif
+
 #if ENABLE_SELINUX
         if (opt & OPT_Z) {
                 if (!is_selinux_enabled())
@@ -1157,7 +1201,7 @@ int ls_main(int argc UNUSED_PARAM, char **argv)
                 char *p = getenv("LS_COLORS");
                 /* LS_COLORS is unset, or (not empty && not "none") ? */
                 if (!p || (p[0] && strcmp(p, "none") != 0)) {
-                        if (isatty(STDOUT_FILENO)) {
+                        if (G_isatty()) {
                                 /* check isatty() last because it's expensive (syscall) */
                                 G_show_color = 1;
                         }
@@ -1166,15 +1210,19 @@ int ls_main(int argc UNUSED_PARAM, char **argv)
         if (opt & OPT_color) {
                 if (color_opt[0] == 'n')
                         G_show_color = 0;
-                else switch (index_in_substrings(color_str, color_opt)) {
-                case 3:
-                case 4:
-                case 5:
-                        if (!is_TERM_dumb() && isatty(STDOUT_FILENO)) {
-                case 0:
-                case 1:
-                case 2:
-                                G_show_color = 1;
+                else if (!G_show_color) {
+                /* if() is not needed, but avoids extra isatty() if G_show_color is already set */
+                        /* Check --color=COLOR_OPT and maybe set show_color=1 */
+                        switch (index_in_substrings(color_str, color_opt)) {
+                        case 3: // auto
+                        case 4: // tty
+                        case 5: // if-tty
+                                if (!is_TERM_dumb() && G_isatty()) {
+                        case 0: // always
+                        case 1: // yes
+                        case 2: // force
+                                        G_show_color = 1;
+                                }
                         }
                 }
         }
@@ -1182,7 +1230,7 @@ int ls_main(int argc UNUSED_PARAM, char **argv)
 
         /* sort out which command line options take precedence */
         if (ENABLE_FEATURE_LS_RECURSIVE && (opt & OPT_d))
-                option_mask32 &= ~OPT_R;        /* no recurse if listing only dir */
+                opt = option_mask32 &= ~OPT_R;  /* no recurse if listing only dir */
         if (!(opt & OPT_l)) { /* not -l? */
                 if (ENABLE_FEATURE_LS_TIMESTAMPS && ENABLE_FEATURE_LS_SORTFILES) {
                         /* when to sort by time? -t[cu] sorts by time even with -l */
@@ -1190,18 +1238,21 @@ int ls_main(int argc UNUSED_PARAM, char **argv)
                         /* without -l, bare -c or -u enable sort too */
                         /* (with -l, bare -c or -u just select which time to show) */
                         if (opt & (OPT_c|OPT_u)) {
-                                option_mask32 |= OPT_t;
+                                opt = option_mask32 |= OPT_t;
                         }
                 }
         }
 
         /* choose a display format if one was not already specified by an option */
-        if (!(option_mask32 & (OPT_l|OPT_1|OPT_x|OPT_C)))
-                option_mask32 |= (isatty(STDOUT_FILENO) ? OPT_C : OPT_1);
+        if (!(opt & (OPT_l|OPT_1|OPT_x|OPT_C)))
+                opt = option_mask32 |= (G_isatty() ? OPT_C : OPT_1);
+
+        if (!(opt & OPT_q) && G_isatty())
+                opt = option_mask32 |= OPT_q;
 
         if (ENABLE_FTPD && applet_name[0] == 'f') {
                 /* ftpd secret backdoor. dirs first are much nicer */
-                option_mask32 |= OPT_dirs_first;
+                opt = option_mask32 |= OPT_dirs_first;
         }
 
         argv += optind;
diff --git a/libbb/getopt32.c b/libbb/getopt32.c
index b5efa19ac..4c05dcb97 100644
--- a/libbb/getopt32.c
+++ b/libbb/getopt32.c
@@ -530,6 +530,7 @@ vgetopt32(char **argv, const char *applet_opts, const char *applet_long_options,
          * "fake" short options, like this one:
          * wget $'-\203' "Test: test" http://kernel.org/
          * (supposed to act as --header, but doesn't) */
+ next_opt:
 #if ENABLE_LONG_OPTS
         while ((c = getopt_long(argc, argv, applet_opts,
                         long_options, NULL)) != -1) {
@@ -544,8 +545,16 @@ vgetopt32(char **argv, const char *applet_opts, const char *applet_long_options,
                          * but we construct long opts so that flag
                          * is always NULL (see above) */
                         if (on_off->opt_char == '\0' /* && c != '\0' */) {
-                                /* c is probably '?' - "bad option" */
-                                goto error;
+                                /* We reached the end of complementary[] and did not find -c */
+                                if (c == '?') /* getopt says: "bad option, or option has no required argument" */
+                                        goto error;
+                                /* if there were options beyond 32 bits (example: ls),
+                                 * they got no complementary[] slot, and no result bit.
+                                 * IOW: they must be "accept but ignore" options.
+                                 * For them, we end up here.
+                                 */
+                                //bb_error_msg("ignored option '%c', skipping", c);
+                                goto next_opt;
                         }
                 }
                 if (flags & on_off->incongruously)