linux编程中read函数以O_APPEND方式打开文件,用lseek将便宜量之余文件开始处,为何写入文件还是在末端写入
int main( int argc, char *argv[] ){
int fileFd;
off_t off;
if( argc != 3 || strncmp( argv[1], "--help", strlen( "--help" ) ==0 ) )
err_quit( "Usage: %s <fileName>", argv[0] );
if( ( fileFd = open( argv[1], O_WRONLY | O_APPEND) ) < 0 )
err_sys( "open %s file error", argv[0] );
off = lseek( fileFd, 0, SEEK_SET );
write( fileFd, argv[2], strlen( argv[2] ) );
exit( EXIT_SUCCESS );
}