Changeset 2725 in MondoRescue for branches/2.2.9/mindi-busybox/coreutils/echo.c

Timestamp:

Feb 25, 2011, 9:26:54 PM (13 years ago)

Author:

Bruno Cornec

Message:

• Update mindi-busybox to 1.18.3 to avoid problems with the tar command which is now failing on recent versions with busybox 1.7.3

File:

• branches/2.2.9/mindi-busybox/coreutils/echo.c (modified) (7 diffs)

branches/2.2.9/mindi-busybox/coreutils/echo.c

@@ -6 +6 @@
  *  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.
@@ -26 +26 @@
 #include "libbb.h"
 
-int bb_echo(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;
@@ -34 +38 @@
         nflag = 1,  /* 1 -- print '\n' */
     };
+
+    /* We must check that stdout is not closed.
+     * The reason for this is highly non-obvious.
+     * 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. */
+// 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)
@@ -41 +60 @@
     char nflag = 1;
     char eflag = 0;
+
+    /* We must check that stdout is not closed. */
+    if (fcntl(1, F_GETFL) == -1)
+        return 1;
 
     while (1) {
@@ -89 +112 @@
 #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);
                 }
             }
-            putchar(c);
+            bb_putchar(c);
         }
 
@@ -107 +134 @@
         if (!arg)
             break;
-        putchar(' ');
+        bb_putchar(' ');
     }
 
  newline_ret:
     if (nflag) {
-        putchar('\n');
+        bb_putchar('\n');
     }
  ret:
-    return fflush(stdout);
-}
-
-/* This is a NOFORK applet. Be very careful! */
-
-int echo_main(int argc, char** argv);
-int echo_main(int argc, char** argv)
-{
-    return bb_echo(argv);
+    return fflush_all();
 }
 
@@ -164 +183 @@
  *  @(#)echo.c  8.1 (Berkeley) 5/31/93
  */
+
+#ifdef VERSION_WITH_WRITEV
+/* We can't use stdio.
+ * The reason for this is highly non-obvious.
+ * 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.
+ *
+ * Using writev instead, with 'direct' conversion of argv vector.
+ */
+
+int echo_main(int argc, char **argv)
+{
+    struct iovec io[argc];
+    struct iovec *cur_io = io;
+    char *arg;
+    char *p;
+#if !ENABLE_FEATURE_FANCY_ECHO
+    enum {
+        eflag = '\\',
+        nflag = 1,  /* 1 -- print '\n' */
+    };
+    arg = *++argv;
+    if (!arg)
+        goto newline_ret;
+#else
+    char nflag = 1;
+    char eflag = 0;
+
+    while (1) {
+        arg = *++argv;
+        if (!arg)
+            goto newline_ret;
+        if (*arg != '-')
+            break;
+
+        /* If it appears that we are handling options, then make sure
+         * that all of the options specified are actually valid.
+         * Otherwise, the string should just be echoed.
+         */
+        p = arg + 1;
+        if (!*p)    /* A single '-', so echo it. */
+            goto just_echo;
+
+        do {
+            if (!strrchr("neE", *p))
+                goto just_echo;
+        } while (*++p);
+
+        /* All of the options in this arg are valid, so handle them. */
+        p = arg + 1;
+        do {
+            if (*p == 'n')
+                nflag = 0;
+            if (*p == 'e')
+                eflag = '\\';
+        } while (*++p);
+    }
+ just_echo:
+#endif
+
+    while (1) {
+        /* arg is already == *argv and isn't NULL */
+        int c;
+
+        cur_io->iov_base = p = arg;
+
+        if (!eflag) {
+            /* optimization for very common case */
+            p += strlen(arg);
+        } else while ((c = *arg++)) {
+            if (c == eflag) {   /* Check for escape seq. */
+                if (*arg == 'c') {
+                    /* '\c' means cancel newline and
+                     * ignore all subsequent chars. */
+                    cur_io->iov_len = p - (char*)cur_io->iov_base;
+                    cur_io++;
+                    goto ret;
+                }
+#if !ENABLE_FEATURE_FANCY_ECHO
+                /* SUSv3 specifies that octal escapes must begin with '0'. */
+                if ( (((unsigned char)*arg) - '1') >= 7)
+#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++;
+                    }
+                    /* bb_process_escape_sequence can handle nul correctly */
+                    c = bb_process_escape_sequence( (void*) &arg);
+                }
+            }
+            *p++ = c;
+        }
+
+        arg = *++argv;
+        if (arg)
+            *p++ = ' ';
+        cur_io->iov_len = p - (char*)cur_io->iov_base;
+        cur_io++;
+        if (!arg)
+            break;
+    }
+
+ newline_ret:
+    if (nflag) {
+        cur_io->iov_base = (char*)"\n";
+        cur_io->iov_len = 1;
+        cur_io++;
+    }
+ ret:
+    /* TODO: implement and use full_writev? */
+    return writev(1, io, (cur_io - io)) >= 0;
+}
+#endif