#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
int main(void)
{
int fd;
fd = open("abc.txt", O_RDONLY);
if (fd < 0)
{
exit(EXIT_FAILURE);
}
printf("fd %d\n", fd);
close(fd);
exit(EXIT_SUCCESS);
}
现在我构建它:
$ cc -errwarn=%all -o ~/tmp/aa ~/tmp/a.c
warning: bad message tag: /export/home/rmashak/tmp/a.call
$ cc -V
cc: Sun C 5.12 SunOS_i386 2011/11/16
它确实执行得很好,但是警告是什么?