接收器控制台从函数输出到.txt文件

Question

我需要在运行带有嵌套函数的代码时填充.txt文件。为此，我使用sink()。输出由a）文本消息，b）数据帧行组成。我无法从嵌套函数内部打印数据框：

sink("log.txt")

cat("Some message")          # Successfully prints to log.txt
head(some_df)                # Successfully prints to log.txt

some_fun = function(x){
    # ...
    cat("Another message")   # Successfully prints to log.txt
    head(another_df)         # Nothing gets printed to log.txt
    # check that another_df is not empty:
    cat(nrow(another_df))    # Successfully prints to log.txt (>0) 
    # ...
}
some_fun(x=0)

sink()

那么正确的方法是什么？