1 files changed, 134 insertions, 22 deletions

diff --git a/coreutils/cat.c b/coreutils/cat.c
index 65978887e..4d9147f8a 100644
--- a/coreutils/cat.c
+++ b/coreutils/cat.c
@@ -12,56 +12,168 @@
 //config:       help
 //config:         cat is used to concatenate files and print them to the standard
 //config:         output. Enable this option if you wish to enable the 'cat' utility.
+//config:
+//config:config FEATURE_CATV
+//config:       bool "cat -v[etA]"
+//config:       default y
+//config:       depends on CAT
+//config:       help
+//config:         Display nonprinting characters as escape sequences
 
-//applet:IF_CAT(APPLET_NOFORK(cat, cat, BB_DIR_BIN, BB_SUID_DROP, cat))
+//applet:IF_CAT(APPLET(cat, BB_DIR_BIN, BB_SUID_DROP))
 
-//kbuild:lib-$(CONFIG_CAT)     += cat.o
+//kbuild:lib-$(CONFIG_CAT) += cat.o
 
 /* BB_AUDIT SUSv3 compliant */
 /* http://www.opengroup.org/onlinepubs/007904975/utilities/cat.html */
 
 //usage:#define cat_trivial_usage
-//usage:       "[FILE]..."
+//usage:       "[-nb"IF_FEATURE_CATV("vteA")"] [FILE]..."
 //usage:#define cat_full_usage "\n\n"
-//usage:       "Concatenate FILEs and print them to stdout"
+//usage:       "Print FILEs to stdout\n"
+//usage:     "\n        -n      Number output lines"
+//usage:     "\n        -b      Number nonempty lines"
+//usage:        IF_FEATURE_CATV(
+//usage:     "\n        -v      Show nonprinting characters as ^x or M-x"
+//usage:     "\n        -t      ...and tabs as ^I"
+//usage:     "\n        -e      ...and end lines with $"
+//usage:     "\n        -A      Same as -vte"
+//usage:        )
+/*
+  Longopts not implemented yet:
+      --number-nonblank    number nonempty output lines, overrides -n
+      --number             number all output lines
+      --show-nonprinting   use ^ and M- notation, except for LFD and TAB
+      --show-all           equivalent to -vet
+  Not implemented yet:
+  -E, --show-ends          display $ at end of each line (-e sans -v)
+  -T, --show-tabs          display TAB characters as ^I (-t sans -v)
+  -s, --squeeze-blank      suppress repeated empty output lines
+*/
 //usage:
 //usage:#define cat_example_usage
 //usage:       "$ cat /proc/uptime\n"
 //usage:       "110716.72 17.67"
 
 #include "libbb.h"
+#include "common_bufsiz.h"
 
-/* This is a NOFORK applet. Be very careful! */
-
-
-int bb_cat(char **argv)
+#if ENABLE_FEATURE_CATV
+/*
+ * cat -v implementation for busybox
+ *
+ * Copyright (C) 2006 Rob Landley <rob@landley.net>
+ *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+/* Rob had "cat -v" implemented as a separate applet, catv.
+ * See "cat -v considered harmful" at
+ * http://cm.bell-labs.com/cm/cs/doc/84/kp.ps.gz
+ * From USENIX Summer Conference Proceedings, 1983
+ * """
+ * The talk reviews reasons for UNIX's popularity and shows, using UCB cat
+ * as a primary example, how UNIX has grown fat. cat isn't for printing
+ * files with line numbers, it isn't for compressing multiple blank lines,
+ * it's not for looking at non-printing ASCII characters, it's for
+ * concatenating files.
+ * We are reminded that ls isn't the place for code to break a single column
+ * into multiple ones, and that mailnews shouldn't have its own more
+ * processing or joke encryption code.
+ * """
+ *
+ * I agree with the argument. Unfortunately, this ship has sailed (1983...).
+ * There are dozens of Linux distros and each of them has "cat" which supports -v.
+ * It's unrealistic for us to "reeducate" them to use our, incompatible way
+ * to achieve "cat -v" effect. The actuall effect would be "users pissed off
+ * by gratuitous incompatibility".
+ */
+#define CATV_OPT_e (1<<0)
+#define CATV_OPT_t (1<<1)
+#define CATV_OPT_v (1<<2)
+static int catv(unsigned opts, char **argv)
 {
-        int fd;
         int retval = EXIT_SUCCESS;
+        int fd;
 
-        if (!*argv)
-                argv = (char**) &bb_argv_dash;
+        BUILD_BUG_ON(CATV_OPT_e != VISIBLE_ENDLINE);
+        BUILD_BUG_ON(CATV_OPT_t != VISIBLE_SHOW_TABS);
+#if 0 /* These consts match, we can just pass "opts" to visible() */
+        if (opts & CATV_OPT_e)
+                flags |= VISIBLE_ENDLINE;
+        if (opts & CATV_OPT_t)
+                flags |= VISIBLE_SHOW_TABS;
+#endif
+
+        /* Read from stdin if there's nothing else to do. */
+        if (!argv[0])
+                *--argv = (char*)"-";
 
+#define read_buf bb_common_bufsiz1
+        setup_common_bufsiz();
         do {
                 fd = open_or_warn_stdin(*argv);
-                if (fd >= 0) {
-                        /* This is not a xfunc - never exits */
-                        off_t r = bb_copyfd_eof(fd, STDOUT_FILENO);
-                        if (fd != STDIN_FILENO)
-                                close(fd);
-                        if (r >= 0)
-                                continue;
+                if (fd < 0) {
+                        retval = EXIT_FAILURE;
+                        continue;
                 }
-                retval = EXIT_FAILURE;
+                for (;;) {
+                        int i, res;
+
+                        res = read(fd, read_buf, COMMON_BUFSIZE);
+                        if (res < 0)
+                                retval = EXIT_FAILURE;
+                        if (res <= 0)
+                                break;
+                        for (i = 0; i < res; i++) {
+                                unsigned char c = read_buf[i];
+                                char buf[sizeof("M-^c")];
+                                visible(c, buf, opts);
+                                fputs(buf, stdout);
+                        }
+                }
+                if (ENABLE_FEATURE_CLEAN_UP && fd)
+                        close(fd);
         } while (*++argv);
 
-        return retval;
+        fflush_stdout_and_exit(retval);
 }
+#endif
 
 int cat_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int cat_main(int argc UNUSED_PARAM, char **argv)
 {
-        getopt32(argv, "u");
+        struct number_state ns;
+        unsigned opts;
+
+        IF_FEATURE_CATV(opt_complementary = "Aetv"; /* -A == -vet */)
+        /* -u is ignored ("unbuffered") */
+        opts = getopt32(argv, IF_FEATURE_CATV("etvA")"nbu");
         argv += optind;
-        return bb_cat(argv);
+
+#if ENABLE_FEATURE_CATV
+        if (opts & 7)
+                return catv(opts, argv);
+//BUG: -v,-e,-t,-A ignore -nb
+        opts >>= 4;
+#endif
+
+#define CAT_OPT_n (1<<0)
+#define CAT_OPT_b (1<<1)
+#define CAT_OPT_u (1<<2)
+        if (!(opts & (CAT_OPT_n|CAT_OPT_b))) /* no -n or -b */
+                return bb_cat(argv);
+
+        if (!*argv)
+                *--argv = (char*)"-";
+        ns.width = 6;
+        ns.start = 1;
+        ns.inc = 1;
+        ns.sep = "\t";
+        ns.empty_str = "\n";
+        ns.all = !(opts & CAT_OPT_b); /* -n without -b */
+        ns.nonempty = (opts & CAT_OPT_b); /* -b (with or without -n) */
+        do {
+                print_numbered_lines(&ns, *argv);
+        } while (*++argv);
+        fflush_stdout_and_exit(EXIT_SUCCESS);
 }