不输出到STDOUT的程序的管道输出

Question

Say I have a program that outputs to a file which is provided by an (required) argument:

./foo -o bar.txt

Is there any way to trick it into outputting to a pipe? This just outputs to a file named - .

./foo -o - | less

Answer 1

您可以使用/dev/stdout作为文件名：

./foo -o /dev/stdout | less

Answer 2

other solution, create a named pipe:

mkfifo /tmp/myfifo; ./foo -o /tmp/myfifo
</tmp/myfifo cat -

Answer 3

这将提供bar.txt的内容以随着文件的增长进行过滤 ：

tail -f bar.txt | filter