Re: [Udpcast] compile udpcast failed

xy zou wrote:

I list symbol from udpcdialog/lib.a

1. cd busybox-1.13.2/udpcdialog
2. nm lib.a | grep "_IO_cleanup"

get result:

            U _IO_cleanup

00000000 T __bring_in_IO_cleanup 00000000 d __elf_set___libc_atexit_element__IO_cleanup__

_IO_cleanup not defined in busybox-1.13.2/udpcdialog/lib.a why ???

The purpose of __bring_in_IO_cleanup is to force the linker to include the function _IO_cleanup , which is responsible for flushing IO buffers before exit. Because of static linking the linker "forgets" to include this, unless such tricks are used.

Without it, some data that application write right before exit might get lost.

Regards,

Alain