xargs: use bb_ask_y_confirmation_FILE() instead of homegrown copy

function                                             old     new   delta
bb_ask_y_confirmation_FILE                             -      83     +83
inetd_main                                          2033    2043     +10
udhcp_send_kernel_packet                             295     301      +6
rmescapes                                            306     310      +4
send_tree                                            353     355      +2
i2cdetect_main                                       674     672      -2
confirm_or_abort                                      43      38      -5
get_terminal_width_height                            242     234      -8
bb_ask_y_confirmation                                 76      10     -66
xargs_main                                           823     755     -68
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 4/5 up/down: 105/-149)          Total: -44 bytes

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

1 files changed, 9 insertions, 3 deletions

diff --git a/libbb/ask_confirmation.c b/libbb/ask_confirmation.c
index ccd983c29..e4814e215 100644
--- a/libbb/ask_confirmation.c
+++ b/libbb/ask_confirmation.c
@@ -8,15 +8,16 @@
  */
 #include "libbb.h"
 
-/* Read a line from stdin.  If the first non-whitespace char is 'y' or 'Y',
+/* Read a line from fp.  If the first non-whitespace char is 'y' or 'Y',
  * return 1.  Otherwise return 0.
  */
-int FAST_FUNC bb_ask_y_confirmation(void)
+int FAST_FUNC bb_ask_y_confirmation_FILE(FILE *fp)
 {
         char first = 0;
         int c;
 
-        while (((c = getchar()) != EOF) && (c != '\n')) {
+        fflush_all();
+        while (((c = fgetc(fp)) != EOF) && (c != '\n')) {
                 if (first == 0 && !isblank(c)) {
                         first = c|0x20;
                 }
@@ -24,3 +25,8 @@ int FAST_FUNC bb_ask_y_confirmation(void)
 
         return first == 'y';
 }
+
+int FAST_FUNC bb_ask_y_confirmation(void)
+{
+        return bb_ask_y_confirmation_FILE(stdin);
+}