lpd: spool mode added by Vladimir

lpr: more robust error reporting
*: introduce and use xchroot
libbb: full_read/write now will report partial data counts prior to error
isdirectory.c: style fixes

lpd_main                                             249     486    +237
xchroot                                                -      29     +29
get_response_or_say_and_die                          110     139     +29
full_write                                            52      60      +8
full_read                                             55      63      +8
static.newline                                         1       -      -1
switch_root_main                                     404     400      -4
chpst_main                                          1089    1079     -10
getopt32                                            1370    1359     -11
chroot_main                                          115     101     -14
------------------------------------------------------------------------------
(add/remove: 1/1 grow/shrink: 4/4 up/down: 311/-40)           Total: 271 bytes
   text    data     bss     dec     hex filename
 798472     728    7484  806684   c4f1c busybox_old
 798775     728    7484  806987   c504b busybox_unstripped

1 files changed, 6 insertions, 0 deletions

diff --git a/libbb/xfuncs.c b/libbb/xfuncs.c
index 17760a3c3..18e696a7a 100644
--- a/libbb/xfuncs.c
+++ b/libbb/xfuncs.c
@@ -577,6 +577,12 @@ void xchdir(const char *path)
                 bb_perror_msg_and_die("chdir(%s)", path);
 }
 
+void xchroot(const char *path)
+{
+        if (chroot(path))
+                bb_perror_msg_and_die("can't change root directory to %s", path);
+}
+
 // Print a warning message if opendir() fails, but don't die.
 DIR *warn_opendir(const char *path)
 {