lineedit: do not hang on error, but return error indicator.

[oweals/busybox.git] / coreutils / echo.c

diff --git a/coreutils/echo.c b/coreutils/echo.c
index 4c7a91743f017e11e8fd7040f45b3d2b91c59e54..3821e594e329ca963dc2f03558ce68f6bfe70825 100644 (file)
--- a/coreutils/echo.c
+++ b/coreutils/echo.c
@@ -5,7 +5,7 @@
  * Copyright (c) 1991, 1993
  *     The Regents of the University of California.  All rights reserved.
  *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  *
  * Original copyright notice is retained at the end of this file.
  */
@@ -25,9 +25,11 @@
 
 #include "libbb.h"
 
-/* argc is unused, but removing it precludes compiler from
- * using call -> jump optimization */
-int bb_echo(int argc, char **argv)
+/* This is a NOFORK applet. Be very careful! */
+
+/* NB: can be used by shell even if not enabled as applet */
+
+int echo_main(int argc UNUSED_PARAM, char **argv)
 {
        const char *arg;
 #if !ENABLE_FEATURE_FANCY_ECHO
@@ -38,14 +40,17 @@ int bb_echo(int argc, char **argv)
 
        /* We must check that stdout is not closed.
         * The reason for this is highly non-obvious.
-        * bb_echo is used from shell. Shell must correctly handle "echo foo"
+        * echo_main is used from shell. Shell must correctly handle "echo foo"
         * if stdout is closed. With stdio, output gets shoveled into
         * stdout buffer, and even fflush cannot clear it out. It seems that
         * even if libc receives EBADF on write attempts, it feels determined
         * to output data no matter what. So it will try later,
         * and possibly will clobber future output. Not good. */
-       if (dup2(1, 1) != 1)
-               return -1;
+// TODO: check fcntl() & O_ACCMODE == O_WRONLY or O_RDWR?
+       if (fcntl(1, F_GETFL) == -1)
+               return 1; /* match coreutils 6.10 (sans error msg to stderr) */
+       //if (dup2(1, 1) != 1) - old way
+       //      return 1;
 
        arg = *++argv;
        if (!arg)
@@ -56,8 +61,8 @@ int bb_echo(int argc, char **argv)
        char eflag = 0;
 
        /* We must check that stdout is not closed. */
-       if (dup2(1, 1) != 1)
-               return -1;
+       if (fcntl(1, F_GETFL) == -1)
+               return 1;
 
        while (1) {
                arg = *++argv;
@@ -106,15 +111,19 @@ int bb_echo(int argc, char **argv)
                                }
 #if !ENABLE_FEATURE_FANCY_ECHO
                                /* SUSv3 specifies that octal escapes must begin with '0'. */
-                               if ( (((unsigned char)*arg) - '1') >= 7)
+                               if ( ((int)(unsigned char)(*arg) - '0') >= 8) /* '8' or bigger */
 #endif
                                {
                                        /* Since SUSv3 mandates a first digit of 0, 4-digit octals
                                        * of the form \0### are accepted. */
-                                       if (*arg == '0' && ((unsigned char)(arg[1]) - '0') < 8) {
-                                               arg++;
+                                       if (*arg == '0') {
+                                               /* NB: don't turn "...\0" into "...\" */
+                                               if (arg[1] && ((unsigned char)(arg[1]) - '0') < 8) {
+                                                       arg++;
+                                               }
                                        }
-                                       /* bb_process_escape_sequence can handle nul correctly */
+                                       /* bb_process_escape_sequence handles NUL correctly
+                                        * ("...\" case). */
                                        c = bb_process_escape_sequence(&arg);
                                }
                        }
@@ -132,15 +141,7 @@ int bb_echo(int argc, char **argv)
                bb_putchar('\n');
        }
  ret:
-       return fflush(stdout);
-}
-
-/* This is a NOFORK applet. Be very careful! */
-
-int echo_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
-int echo_main(int argc, char **argv)
-{
-       return bb_echo(argc, argv);
+       return fflush_all();
 }
 
 /*-
@@ -185,7 +186,7 @@ int echo_main(int argc, char **argv)
 #ifdef VERSION_WITH_WRITEV
 /* We can't use stdio.
  * The reason for this is highly non-obvious.
- * bb_echo is used from shell. Shell must correctly handle "echo foo"
+ * echo_main is used from shell. Shell must correctly handle "echo foo"
  * if stdout is closed. With stdio, output gets shoveled into
  * stdout buffer, and even fflush cannot clear it out. It seems that
  * even if libc receives EBADF on write attempts, it feels determined
@@ -195,7 +196,7 @@ int echo_main(int argc, char **argv)
  * Using writev instead, with 'direct' conversion of argv vector.
  */
 
-int bb_echo(int argc, char **argv)
+int echo_main(int argc, char **argv)
 {
        struct iovec io[argc];
        struct iovec *cur_io = io;
@@ -297,6 +298,6 @@ int bb_echo(int argc, char **argv)
        }
  ret:
        /* TODO: implement and use full_writev? */
-       return writev(1, io, (cur_io - io)) >= 0; 
+       return writev(1, io, (cur_io - io)) >= 0;
 }
 #endif